<p dir="ltr" id="isPasted">As our world increasingly relies on sound, the demand for pristine audio quality rises. Clear and crisp audio has become essential for various applications such as voice assistants and video conferencing. However, background noise can often interfere with audio quality, making communication and entertainment less enjoyable. Effective audio denoising is essential for these applications.&nbsp;</p><p dir="ltr">BrainChip has developed an Audio Denoising solution that uses <a href="https://brainchip.com/tenns-akida-2-0/" target="_blank">Temporal Event Neural Networks (TENNs)</a>, a set of algorithms designed to enhance performance and power efficiency.&nbsp;</p><p dir="ltr">The Audio Denoising solution stands out by minimizing the need for extensive data conversion that consumes significant power. This efficiency supports better audio quality and aligns with the growing demand for sustainable technology solutions in the audio industry.</p><h2 dir="ltr">The Challenge of Audio Denoising</h2><p dir="ltr">Audio denoising has long been a complex challenge in signal processing. Traditional methods often lack balancing noise reduction while preserving sound quality.&nbsp;</p><ul><li dir="ltr"><p dir="ltr">One of the main challenges in audio denoising is distinguishing between desired audio and unwanted noise. This can be especially difficult when the noise has similar characteristics to the audio signal, such as in background conversations or environmental sounds.&nbsp;</p></li><li dir="ltr"><p dir="ltr">Another challenge is in the computational complexity of audio denoising algorithms. Many traditional methods require significant processing power and memory resources, making them unsuitable for deployment on resource-constrained devices.&nbsp;</p></li></ul><p dir="ltr">These limitations have become problematic as the demand for real-time audio processing grows in various applications.&nbsp;</p><h2 dir="ltr">BrainChip Audio Denoising: A Solution to Unwanted Noise</h2><p dir="ltr">BrainChip's Audio Denoising solution enhances audio quality by removing unwanted noise. Powered by TENNs, this solution offers improvements in performance and energy efficiency. This makes it a good option for edge-computing audio applications.</p><h3 dir="ltr">Key Features of BrainChip Audio Denoising</h3><ul><li dir="ltr"><p dir="ltr">The solution includes medium-sized models that achieve an impressive Perceptual Evaluation of Speech Quality (PESQ) score of 3.36 with just 590,000 parameters. This makes it highly scalable to meet specific customer needs.</p></li><li dir="ltr"><p dir="ltr">The TENN models require fewer computational resources compared to traditional models. They use 12 times fewer multiply-accumulate operations (MACs) and nearly three times fewer parameters. This leads to lower power consumption.</p></li><li dir="ltr"><p dir="ltr">The Audio Denoising solution comes with integrated Hardware IP. It can easily be incorporated into System-on-Chip (SoC) designs for optimal performance in audio processing tasks.</p></li><li dir="ltr"><p dir="ltr">It is suitable for a range of devices, including wireless earbuds, VoIP systems, and smart home products. It can also be used as a standalone feature or as part of a more extensive system.</p></li><li dir="ltr"><p dir="ltr">Customers with a TENNs license can fine-tune the TENN models to cater to specific audio environments. This ensures tailored performance for various use cases.</p></li></ul><h2 dir="ltr">Benefits of Audio Denoising Solution</h2><p dir="ltr">BrainChip Audio Denoising solution provides several important benefits for various applications:</p><ul><li dir="ltr"><p dir="ltr"><strong>Improved Sound Quality:</strong> This solution enhances audio clarity by removing unwanted noise. This makes conversations, music, and other sounds more enjoyable.</p></li><li dir="ltr"><p dir="ltr"><strong>Better Communication:</strong> Denoising improves speech intelligibility in noisy environments, such as busy offices or public places, making conversations easier to understand.</p></li><li dir="ltr"><p dir="ltr"><strong>Enhanced User Experience:</strong> Clear audio is important for devices like hearing aids or smart speakers. BrainChip Denoising ensures users can hear content without distractions from background noise.</p></li><li dir="ltr"><p dir="ltr"><strong>Energy Efficiency:</strong> The Denoising solution consumes less power. This extends the battery life of devices, which is essential for portable electronics.</p></li></ul><h2 dir="ltr">Real-World Applications of BrainChip Denoising Solution</h2><p><span class="fr-img-caption fr-fic fr-dii" style="width: 780px;"><span class="fr-img-wrap"><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1722510951059-1722510951059.png" width="624" height="416" id="isPasted" class="fr-fic fr-dii"><span class="fr-inner">BrainChip Audio Denoising solution can enhance audio quality and improve user experiences in multiple settings.</span></span></span></p><h3 dir="ltr"><strong>1. Smart Home Devices</strong></h3><p dir="ltr">The solution plays a vital role in smart home technology. By improving the accuracy of voice-controlled systems, it ensures that commands are recognized correctly. This leads to better functionality and user satisfaction.</p><h3 dir="ltr">2. Industrial Monitoring</h3><p dir="ltr">In industrial settings, the solution enhances the quality of audio data. This improvement leads to more accurate analysis and predictive maintenance. This offers increased efficiency and safety in operations.</p><h3 dir="ltr">3. Medical Devices</h3><p dir="ltr">The technology also applies to medical devices, which aid in vital sign estimation. This capability offers accurate and energy-efficient monitoring of human health, which is important in healthcare settings.</p><h3 dir="ltr">4. Speech Clarity</h3><p dir="ltr">The Denoising solution can also be used in voice calls and audio recordings. TENN models remove background noise and allow the speaker's voice to come through clearly. This feature is beneficial for mobile devices and hearing aids, where clear communication is essential.</p><h3 dir="ltr">5. VoIP Communication</h3><p dir="ltr">The BrainChip Denoising solution improves audio quality in video conferencing and online meetings. Providing more precise and noise-free audio enhances the experience of remote work. This way, the conversations can be more productive and enjoyable.</p><h2 dir="ltr">Implementation and Future Directions</h2><p dir="ltr">BrainChip Audio Denoising solution is also integrated into the Akida 2.0 IP, optimized for TENNs technology. The architecture includes a network of nodes, each equipped with an event-based TENN processing unit. This provides a powerful platform for audio processing tasks.</p><ul><li dir="ltr"><p dir="ltr">Future developments will aim to improve efficiency by enhancing activation sparsity, which will reduce the number of active computations needed.&nbsp;</p></li><li dir="ltr"><p dir="ltr">There will also be a focus on exploring more flexible model architectures to adapt to different audio processing needs.&nbsp;</p></li><li dir="ltr"><p dir="ltr">Additionally, integrated solutions will be developed to combine audio denoising with speech recognition and keyword spotting tasks. This will offer a more comprehensive audio processing toolkit.</p></li></ul><h2 dir="ltr">Final Words</h2><p dir="ltr">BrainChip's Audio Denoising Solution is a big step forward in audio processing technology. By managing power consumption and computational demands, the solution supports the development of edge devices that provide clear audio in various environments.&nbsp;</p><p dir="ltr">This smart technology can make a big difference in how you enjoy your music, videos, and calls. With less noise and better sound, you can focus on what matters.</p>

BrainChip Audio Denoising solution uses Temporal Event Neural Networks (TENNs) to support better audio quality by removing unwanted voices. 

The Audio Revolution at the Edge

<p id="isPasted"><span data-contrast="auto" lang="EN-US">Three-and-a-half</span><span data-contrast="auto" lang="EN-US">&nbsp;years on from the Bluetooth Special Interest Group’s (SIG) announcement of a new specification that defined a high quality, low-power audio codec (Low Complexity Communications Codec or LC3) that promised to redefine audio streaming and wireless sound,&nbsp;</span><a href="https://www.nordicsemi.com/Products/Wireless/Bluetooth-LE-Audio" target="_blank" rel="noreferrer noopener"><span data-contrast="none" lang="EN-US"><span data-ccp-charstyle="Hyperlink">Bluetooth LE Audio</span></span></a><span data-contrast="auto" lang="EN-US">&nbsp;(LE Audio) is finally about to hit the commercial mainstream.</span></p><p><span data-contrast="auto">The delay has due to the development time needed to shake out the bugs from what is a complex technology. As Chuck Sabin, Senior Director, Market Development at the SIG says, developing specifications is hard, particularly when there are billions of Bluetooth-enabled receiving devices out there. That’s a lot of interested parties invested in ensuring the specification is going to deliver so things work perfectly.</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><p><span data-contrast="auto">With the due diligence now complete, and a year on from the adoption of the specification, the first commercial implementations of LE Audio are now coming to market. Within another three or four years, Sabin predicts—once the tech is natively adopted by iOS and Android smartphones and major wireless audio device vendors—LE Audio will be universal.&nbsp;</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><p><span data-contrast="auto">When it is, wireless audio will become unrecognizable from anything we’ve previously experienced, and not just for the millions of us that use wireless headphones and earbuds, but more importantly for the hearing impaired as well.&nbsp;</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><h2><span data-contrast="auto" lang="EN-US">True Wireless Stereo&nbsp;and&nbsp;better battery life</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></h2><p><span data-contrast="auto">Two key advantages of LE Audio over Classic Audio that will drive mass consumer adoption are the noticeable improvements in audio quality and longer playtime.&nbsp;</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><p><span data-contrast="auto">While Bluetooth LE supports multiple communication topologies for data transfer (for example, Bluetooth Mesh), it only supports point-to-point communication for audio streaming. LE Audio’s multi-stream audio functionality however enables multiple devices—for example a pair of earbuds—to receive their own unique audio stream. The left and right channels retain the original precise musical timing upon replay. The result is excellent stereo sound together with long battery life. That’s unlike the earbuds in use today that can only stream audio to a single device and therefore require an engineering work around to retransmit the second channel to a second earbud, at the cost of battery life.</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><p><span data-contrast="auto">On the question of battery life, quantifying the expected reduction in power consumption over Classic Audio is difficult because it will depend on both implementation and product use. Product developers focused on providing the highest audio quality might choose to implement the LC3 codec for hi-fidelity rather than aiming for significant gains in playback time. Others may choose to focus entirely on extending battery life by trading-off sound quality. In the latter case, the battery life of your earbuds or Bluetooth speaker could double.</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><h2><span data-contrast="auto" lang="EN-US">Auracast&nbsp;broadcast audio promotes&nbsp;inclusion</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></h2><p><span data-contrast="auto">Another breakthrough feature of LE Audio is the addition of Auracast broadcast audio. Auracast allows an audio source device such as a smartphone, laptop, TV, or sound system to broadcast one or several audio streams to an unlimited number of Bluetooth audio receivers.&nbsp;</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><p><span data-contrast="auto">There are several potential use cases for Auracast, but chief among them is the ability for it to become a high quality, lower cost augmented and assistive listening technology in venues where PA or hearing loop infrastructure is currently deployed. Such a use case opens up wider accessibility for the over 1.5 billion people living with hearing loss around the world. It can also enable multi-language audio streams in locations that support simultaneous translation services.&nbsp;</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><h2><span data-contrast="auto" lang="EN-US">Next gen SoCs&nbsp;optimized for LE Audio</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></h2><p><span data-contrast="auto">While LE Audio’s LC3 codec does demand more computational resource than Classic Audio’s SBC codec to compress and decompress audio, the latest generation of wireless SoCs can comfortably meet this requirement without compromising any power consumption advantages. For example, Nordic Semiconductor’s&nbsp;</span><a href="https://www.nordicsemi.com/Products/nRF5340" target="_blank"><span data-contrast="none">nRF5340</span></a><span data-contrast="auto"> SoC features a dedicated Arm Cortex-M33 application processor, optimized for performance and with ample overhead to look after the computational demands of advanced audio codecs. The SoC incorporates a second M33 processor to supervise wireless connectivity and which is optimized for low power consumption.</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><p><span data-contrast="auto">Looking forward to mass commercialization of LE Audio, Nordic’s fourth generation of wireless SoCs, the&nbsp;</span><a href="https://www.nordicsemi.com/Products/nRF54L15" target="_blank"><span data-contrast="none">nRF54L15</span></a><span data-contrast="auto">&nbsp;and&nbsp;</span><a href="https://www.nordicsemi.com/Products/nRF54H20" target="_blank"><span data-contrast="none">nRF54H20</span></a><span data-contrast="auto">&nbsp;are both now sampling, and represent the future of not just LE Audio, but for many applications demanding complex machine learning (ML) and support for sensor fusion at the edge. The&nbsp;</span><span data-contrast="auto">nRF54H20 SoC features multiple Arm Cortex-M33 processors and multiple RISC-V coprocessors optimized for specific types of workloads. The level of integration this will provide product developers ensures tomorrow’s LE Audio solutions—from earbuds to hearing aids—will consume even less energy, be smaller, and simpler to bring to market.</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><h2><span data-contrast="auto" lang="EN-US">LE Audio and&nbsp;Auracast&nbsp;world first</span><span data-ccp-props='{"201341983":0,"335559739":0,"335559740":259}'>&nbsp;</span></h2><p><span data-contrast="auto">The first commercialized LE Audio solutions are already available. Earlier this year, global hearing technology solutions provider GN launched a&nbsp;</span><a href="https://www.nordicsemi.com/Nordic-news/2024/01/GN-Group-unveils-Nordic-powered-Bluetooth-LE-Audio-and-Auracast-broadcast-audio-TV-streamer" target="_blank"><span data-contrast="none">world first LE Audio and Auracast broadcast audio TV streamer</span></a><span data-contrast="auto">, enabling people suffering from hearing loss to stream hi-fidelity audio between their television and their hearing aids, with all the benefits of Auracast. Working seamlessly with the company’s new ReSound Nexia hearing aids or other LE Audio compatible solutions, the TV-Streamer+ integrates a Nordic’s LE Audio- and Auracast-capable SoC to deliver low power, low latency, and long range wireless connectivity with improved audio quality.&nbsp;</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p><p><span data-contrast="auto">For people with hearing loss the launch means they can enjoy immediate speech clarity at their preferred volume, while at the same time enjoying the benefits of Auracast. For developers and consumers, it means the LE Audio and Auracast are in the public eye.</span><span data-ccp-props='{"201341983":0,"335559739":160,"335559740":259}'>&nbsp;</span></p>

Three-and-a-half years on from the Bluetooth Special Interest Group’s (SIG) announcement of a new specification that defined a high quality, low-power audio codec that promised to redefine audio streaming and wireless sound, Bluetooth LE Audio is finally about to hit the commercial mainstream.

Bluetooth LE Audio and Auracast going mainstream will redefine wireless audio

Audio event detection functions can listen for distinct sounds or patterns embedded within an audio stream. It uses advanced signal processing and machine learning algorithms to accurately identify and classify sound events in real-time, with no internet connectivity required.

Implementing Audio Event Detection on the Edge with Particle Photon 2

<p id="isPasted">Near ubiquitous wireless tech is making everyday life simpler, safer, and healthier for billions. And as ambitious developers take advantage of evolving technologies, connected devices with smaller form factors will do even more using even less power. But this brave new world hasn&rsquo;t happened overnight.</p><p>A pivotable moment in the remarkable rise of wireless innovation can be traced back a quarter of a century to the emergence of Bluetooth &ndash; an interoperable protocol that became a standard, accompanied by an open specification for both hardware and software. In its various forms, Bluetooth has powered a significant segment of the connected world ever since.</p><h2><strong>Changing the game with Bluetooth LE</strong></h2><p>The release of the original Bluetooth Classic standard drove impressive growth. Still, the introduction in 2010 of a low-energy version, Bluetooth Low Energy&nbsp;(<a href="https://www.nordicsemi.com/Products/Bluetooth-Low-Energy?utm_campaign=2021%20wevolver" target="_blank" rel="noopener noreferrer">Bluetooth LE</a>), dramatically expanded the technology&rsquo;s range of applications. The development of Bluetooth LE was pushed along by partners, including Nordic Semiconductor &ndash; at the time, a company already renowned as a pioneer in ultra-low power, high-performance wireless connectivity.</p><p>Bluetooth LE was a game changer because its ultra-low power consumption meant data could be gathered from sensors without requiring frequent battery recharge or replacement. And because handset makers were familiar with the original Bluetooth tech, they rapidly adopted support for the low-power version in their new mobiles.</p><p>This was the catalyst for a huge market in &ldquo;appcessories&rdquo;, wirelessly linked peripheral devices such as fitness bands that were able to leverage the smartphone&rsquo;s computational horsepower. Today&rsquo;s highly-advanced wearables represent just the latest chapter in that story.</p><h2><strong>Planet Bluetooth expands</strong></h2><p>The expansion of &lsquo;Planet Bluetooth&rsquo; has been due to both constant enhancements to the Bluetooth Core Specification&mdash;the technical name for the document that details how to build Bluetooth devices&mdash;and the powerful Bluetooth SoCs with their associated application software that power increasingly sophisticated applications.</p><p>For example, the introduction of Bluetooth 5 in mid-2016 added some key capabilities to Bluetooth tech&mdash;notably increased range or higher data throughput&mdash;which helped improve functionality across a gamut of wireless applications from smart watches to smart agriculture.</p><p>The July 2017 release of the Bluetooth mesh 1.0 specification&mdash;as the name suggests, a mesh networking technology&mdash;provided vital functionality for applications in smart lighting, predictive maintenance, asset tracking, and locationing, among others.</p><p>In 2019, a further update to the Bluetooth Specification, Bluetooth 5.1, brought another powerful application of the technology to the fore &ndash; Direction Finding, a feature that opens up new possibilities for accurate indoor positioning of both assets and people.</p><p>In the lucrative audio market, LE Audio is described as the &lsquo;future of wireless sound&rsquo; and now allows engineers to enhance both the sound quality and power consumption of wireless audio products. The Bluetooth SIG says that in 2022, 1.36 billion Bluetooth audio streaming devices&mdash;including headsets, headphones, speakers, and earbuds &ndash; were shipped globally. An even more recent development, Auracast broadcast radio, is set to reshape audio sharing.</p><h2>Bluetooth cements its place in the smart home</h2><p>Bluetooth is also the wireless tech of choice for commissioning smart home devices. While smart home device manufacturers can select from several low-power wireless protocols, Bluetooth&#39;s unique advantage is its interoperability with smartphones and tablets. And with its inclusion in Matter, Bluetooth tech&#39;s place in the smart home is now cemented.</p><p>Thanks to these applications and many others, Bluetooth chips are used in their billions. And further growth is forecast. According to the Bluetooth Special Interest Group (SIG), 2023 will see the shipment of 5.4 billion Bluetooth devices &ndash; a figure expected to climb to 7.6 billion by 2027.</p><h2><strong>Pioneer becomes leader</strong></h2><p>Nordic&rsquo;s decision to back the Bluetooth LE open standard&mdash;just as it has with <a href="https://www.nordicsemi.com/Products/Low-power-cellular-IoT?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">cellular IoT</a>, <a href="https://www.nordicsemi.com/Products/DECT-NR?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">DECT NR+</a>, and <a href="https://www.nordicsemi.com/Products/WiFi?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">Wi-Fi</a> in more recent times&mdash;meant ceding much of its hard-won intellectual property (IP) to others. But such a decision proved a masterstroke; Nordic&#39;s chip shipments made it the global market leader when the low-power wireless segment exploded.</p><p>Today, Nordic&rsquo;s award-winning, high-performance, yet easy to design-in Bluetooth LE solutions are used by the world&rsquo;s leading brands in myriad products from sports and fitness to industrial automation and education.</p><p>According to Bluetooth SIG data compiled by DNB Markets, Nordic had a market share of 39 percent of new design certifications in the Bluetooth LE market in 2021. And a total of more than 1,100 new designs were certified in 2022, of which 446 had Nordic inside.</p><p>Through successive product introductions, Nordic&#39;s chips have continually evolved in performance&mdash;primarily based on the use of more advanced semiconductor manufacturing tech, more generous memory, greater processing power, and highly-refined software. Each new generation has allowed developers to push the boundaries of innovation without making major sacrifices in power consumption.</p><h2><strong>Applications once unimagined</strong></h2><p>Like the capability of its products, the performance of applications enabled by Nordic&#39;s low-power wireless tech continues to improve. Two prominent examples include a high-end health monitoring wearable launched by U.S.-based human performance company <a href="https://www.nordicsemi.com/News/2022/07/The-WHOOP-4-uses-Nordics-nRF52840-SoC?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">WHOOP</a> and China-based OctoNet&rsquo;s <a href="https://www.nordicsemi.com/News/2023/05/OctoNet-Bluetooth-positioning-gateway-employs-nRF52840-and-nRF52833-SoCs?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">Bluetooth positioning gateway</a>, which uses the <a href="https://www.nordicsemi.com/products/nrf52833?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">nRF52833</a> SoC&rsquo;s direction-finding capabilities to keep track of high-value hospital equipment and the whereabouts of staff in hospitals.</p><p>The list of similarly advanced applications employing Nordic-enabled Bluetooth LE wireless connectivity is extensive. And as Bluetooth continues to spread and evolve, engineers using the omnipresent tech will keep coming up with applications once unimagined. The most recent update is Bluetooth 5.4, which includes enhancements that enable connectionless, bidirectional, secure communication with thousands of very low-power end nodes in a star topology network. Such a topology suits applications such as electronic shelf labels.</p><p>Bluetooth LE technology has become synonymous with the connected lifestyle across the globe. Whether a dedicated athlete, an intrepid adventurer, a patient with an acute medical condition, or simply a typical consumer in the developed world, we&rsquo;re all citizens of Planet Bluetooth.</p><hr><p>This article was first published on Nordic&#39;s&nbsp;<a href="https://blog.nordicsemi.com/getconnected" target="_blank" rel="nofollow" id="isPasted"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" target="_blank" rel="nofollow">Get Connected Blog</a>. &nbsp;</p>

A pivotable moment in the remarkable rise of wireless innovation can be traced back a quarter of a century to the emergence of Bluetooth – an interoperable protocol that became a standard, accompanied by an open specification for both hardware and software. In its various forms, Bluetooth has powered a significant segment of the connected world ever since.

The rise and rise of Bluetooth

<p id="isPasted">The latest Bluetooth development may not yet be on everyone&rsquo;s radar, but Auracast broadcast audio is set to revolutionize sound sharing.</p><p>By allowing an audio source device to broadcast to an unlimited number of receivers, this location-based broadcast application (with a user interface similar to Wi-Fi hotspots) could dramatically change how people consume content and interact with their environment. Better yet, Auracast will be viable across multiple end markets &ndash; from hearing-impaired support services through mass information systems to hospitality.</p><h2><strong>Next gen Bluetooth audio tech</strong></h2><p>Auracast broadcast audio is a key new capability enabled by the release of LE Audio &ndash; the new generation of Bluetooth audio technology created to complement Classic Audio with a high-quality audio streaming option. The introduction of LE Audio added new features which support superior sound, lower latency, reduced power consumption, and enhanced interoperability, plus ease the development of new audio device types.</p><p>LE Audio is primed to play an increasingly central role in how people listen to content and engage with their environment. A report compiled by analyst ABI Research on behalf of the Bluetooth Special Interest Group (SIG) forecasts three billion Bluetooth LE Audio-enabled devices will be shipped in 2027. That figure was 115.5 million in 2022.</p><h2><strong>Helping the world sound better with Auracast</strong></h2><p>Technically, Auracast defines a specific set of requirements that uses Bluetooth tech&rsquo;s Public Broadcast Profile (PBP) specification for a universal format and availability of a public broadcast.</p><p>In practical use, Auracast allows an audio source device like a smartphone, laptop, TV, public address (PA), or sound system to broadcast one or several audio streams to an unlimited number of Bluetooth audio receivers. The broadcast would use <a data-lf-fd-inspected-kn9eq4roawkarlvp="true" href="https://www.nordicsemi.com/-/media/Publications/Wireless-Quarter-pdf/2020/NS_WQ_Issue1_2020_1.pdf?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">Bluetooth 5.2 specification</a>&#39;s Isochronous Channels to transmit signals to things like headphones, True Wireless Stereo (TWS) earbuds, or more specialized audio products like hearing aids.</p><p>With ABI Research suggesting&nbsp;57 percent&nbsp;of users plan to increase the time they spend using their audio devices, Auracast enables new market opportunities to attract consumers with both public and private broadcast use cases.</p><h2><strong>Tuning in anywhere with LE Audio</strong></h2><p>The Bluetooth SIG has identified five of these audio use cases. The primary promoted use case for Auracast is for it to become a high-quality, lower-cost augmented and assistive listening technology in venues where a PA or hearing loop infrastructure is currently deployed.</p><p>Thanks to its connectionless broadcast capabilities, LE Audio allows any number of users to effectively tune into various public audio streams using their own devices. Such a use case opens up wider accessibility for over 1.5 billion people (nearly 20 percent of the global population) suffering with hearing loss. This is a group the World Health Organization (WHO) anticipates will grow to 2.5 billion by 2050.</p><p>Auracast can also enable multi-language audio streams in locations that support simultaneous translation services. Users will be able to tune into a relevant stream for their preferred language.</p><p>A more niche use case enables people to join audio tours in venues such as museums, stadiums, and tourist attractions. Elsewhere, individuals could use their Auracast assistant and headset device to tune into the audio of a particular screen at a venue where televisions are installed, but no audio is provided, or where the audio is hard to hear. Longer term, one-to-one or counter-based assistive listening applications could emerge in retail and other service environments.</p><h2><strong>Getting started with Auracast</strong></h2><p>To bring such use cases to life and make the most of Auracast&rsquo;s potential, Bluetooth LE SoCs with plenty of processing power yet modest energy consumption are in demand. An ideal solution is Nordic Semiconductor&rsquo;s <a href="https://www.nordicsemi.com/Products/nRF5340?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">nRF5340</a> SoC, which incorporates two processor cores&mdash;one a dedicated application processor, the other a power optimized network processor&mdash;and an advanced feature set, provides the ideal combination of performance and energy use to meet the demands of LE Audio and advanced &lsquo;hearable&rsquo; applications.</p><p>Nordic&rsquo;s <a href="https://www.nordicsemi.com/Products/Development-hardware/nRF5340-Audio-DK?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">nRF5340 Audio DK</a> supports all Auracast features and incorporates everything developers need to embark on LE Audio projects. The Development Kit is configurable and can function as a USB dongle to send or receive audio data from a PC, a business headset, or a TWS Earbud.</p><h2><strong>The future of hearing</strong></h2><p>Soon, everyone will be able to seamlessly use their own devices to experience ground-breaking Auracast technology. Public venues&nbsp;like auditoriums, lecture halls, cinemas, theaters, and transit centers will add support for Auracast broadcast audio to existing sound systems, bringing audio clarity to people wherever they go. And it won&rsquo;t be long before locations like sports bars, gymnasiums, restaurants, and waiting areas add support for Auracast to their silent TVs, allowing visitors to unmute screens if they so wish.</p><p>Picture an airport terminal, where even in the best circumstances, boarding and gate announcements can be difficult to hear. Now airports will be able to add support for Auracast to their existing sound system so visitors can hear high-quality public address audio in their Bluetooth&nbsp;earbuds or hearing aids. And air travelers could select the Auracast broadcast for their specific terminal, filtering out unnecessary announcements.</p><h2><strong>A market on the move</strong></h2><p>All signs point to the Auracast broadcast audio market making a massive impact this decade. According to ABI Research, by 2030 there will be nearly 2.5 million Auracast deployments across venues such as libraries, social or meeting venues, recreational facilities, entertainment and culture, and airports and transportation hubs. Public assembly use cases will account for nearly 42 percent of those deployments. Silent TV screens, assistive listening, and multi-language support applications are expected to become increasingly prevalent over time.</p><p>As the market develops and the installed base of Auracast devices grows, new use cases are likely to emerge. The world is about to open its ears like never before.</p><hr><p>This article was first published on Nordic&#39;s&nbsp;<a href="https://blog.nordicsemi.com/getconnected" target="_blank" rel="nofollow" id="isPasted"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" rel="nofollow" target="_blank">Get Connected Blog</a>.  &nbsp;</p>

The latest Bluetooth development may not yet be on everyone’s radar, but Auracast broadcast audio is set to revolutionize sound sharing.

Auracast broadcast audio transforms sound sharing

True Wireless Stereo (TWS)  devices will be ready for any acoustic environment in everyday life  


Redefining hearing and communication with TWS earbuds and hearables

<p id="isPasted">Recording technology has followed a path of increasing fidelity since the days of wax grooves on a cylinder with mechanical playback. Later those grooves were carved into vinyl and the music reproduced electrically. Then magnetic tape enhanced the quality of recorded sound from the 1940s through to the 1970s.&nbsp;The analogue era was then brushed aside by digital recording, using technology pioneered by Sony, which peaked with today&rsquo;s CD-quality sound.</p><p>But it turns out that the relentless drive for greater sound quality might have been misplaced. It seems that beyond Hi-Fi aficionados, listeners are happy with digital sound delivered at bitrates well below those offered by CD&mdash;provided it&rsquo;s done cleverly&mdash;and that&rsquo;s proved a boon for wireless audio product designers.</p><h2>The psychology of sound</h2><p>Engineers use coder/encoders (&ldquo;codecs&rdquo;) to stream audio sound across a wireless link. The codecs use a compression format to squeeze the digitized music and lower the throughput required to wirelessly transmit. The compression formats help improve range and lower power consumption.</p><p>Some popular compression techniques use &lsquo;lossy&rsquo; formats whereby before transmission, the encoder discards information considered not needed to maintain the quality of reproduction, in order to increase compression. The developers of lossy formats have been guided by psychoacoustic models which help them determine which information can be discarded. But not all psychoacoustic models are equal and otherwise equivalent compression algorithms can result in very different sound quality.</p><h2>Bluetooth Audio evolves</h2><p>The Bluetooth Special Interest Group (SIG) developed its own wireless streaming technology as far back as 2003.&nbsp;Called the Advanced Audio Distribution Profile (A2DP), the technology facilitated audio streaming between two Bluetooth devices and introduced the low complexity sub-band codec (SBC).</p><p>SBC did a reasonable job but suffered from some drawbacks. Key among these was a channel limitation that only allowed streaming audio to a single device such as the left-hand unit of a pair of earbuds. Engineers overcame the problem by processing the incoming Bluetooth audio stream in one earbud and then from there wirelessly retransmitting the second channel to the other earbud. The technique worked but was processor intensive and shortened battery life.</p><p>Now a new Bluetooth SIG codec, called the Low Complexity Communications Codec (LC3), is both addressing the drawbacks of SBC and bringing some new features of its own. LC3 forms the backbone of <a href="https://www.nordicsemi.com/Products/Bluetooth-LE-Audio?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">LE Audio</a>, which the Bluetooth SIG describes as &ldquo;the future of wireless sound&rdquo;.</p><p>Through innovative compression techniques, LC3 promises improved audio quality and better battery life than SBC for all use cases. A key factor in extending battery life is that LC3 provides the same audio quality as SBC but at half the throughput. LE Audio also brings true wireless stereo (TWS) and other new functions to wireless audio including Audio Sharing.</p><h2>Number crunching power</h2><p>LC3 does demand more computational resource than SBC to compress and decompress the music. Previously that would threaten to erode some of the power advantage gained by the lower throughout for a given audio quality, but the new generation of wireless SoCs provide the answer. Bluetooth LE SoCs such as Nordic Semiconductor&rsquo;s <a href="https://www.nordicsemi.com/Products/nRF5340?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">nRF5340</a> offer plenty of processing power yet at a much lower processor energy consumption than previous generations of chips.</p><p>The nRF5340 features a dedicated Arm Cortex M33 application processor, optimized for performance and with ample overhead to look after the computational demands of advanced audio codecs. The SoC incorporates a second M33 processor to supervise wireless connectivity and which is optimized for low power consumption. The result is an SoC with the ideal combination of performance and energy use to meet the demands of LE Audio.</p><h2>Accelerate wireless audio development</h2><p>Nordic is making it easy for developers to get started on LE Audio projects with its <a href="https://www.nordicsemi.com/nRF5340-Audio-DK?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">nRF5340 Audio DK</a>. The DK makes it easy to embark on LE Audio projects. It is highly configurable allowing it to function as a USB dongle to send and receive high-quality audio data from a PC, a business headset, or a TWS earbud.</p><p>The Audio DK features Nordic&rsquo;s <a href="https://www.nordicsemi.com/Products/nPM1100?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">nPM1100</a> power management IC (PMIC), and Cirrus Logic&rsquo;s CS47L63 Audio digital signal processor (DSP). The PMIC features a highly efficient configurable buck regulator and an integrated battery charger and its extremely small form factor makes it ideal for space-constrained applications like TWS Earbuds. The CS47L63 is optimized for direct connection to an external headphone load and suits earbuds with mono-only and direct speaker output.</p><h2>No trade-offs</h2><p>LE Audio brings no technical trade-offs limiting what a designer can do. It brings better audio quality, more robust wireless connectivity and vastly improved battery life compared with Classic Audio. An engineer can, for example, design earbuds with incredible sound quality and extended battery life by designing with LE Audio. Alternatively, they can use smaller batteries to shrink the product&rsquo;s form factor and direct material costs, while still matching the original product&rsquo;s playtime.</p><p>And with the nRF5340 Audio DK and Nordic&rsquo;s nRF5340 SoC, getting those compelling wireless audio products to market quickly is made easy.</p><hr><p>This article was first published on Nordic&#39;s&nbsp;<a href="https://blog.nordicsemi.com/getconnected" target="_blank" rel="nofollow" id="isPasted"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" rel="nofollow" target="_blank">Get Connected Blog</a>.  &nbsp;</p>

Technology described as the ‘future of wireless sound’ allows engineers to enhance the sound quality and power consumption of wireless audio products

LE Audio ready for developers of next-generation wireless sound products

<p>In this episode, we talk about why minimization of speakers and energy storage devices is crucial for the next generation of electronics and medical devices. As always, you can find these and other interesting &amp; impactful engineering articles on Wevolver.com.&nbsp;</p><p><span class="fr-video fr-deletable fr-fvc fr-dvb fr-draggable" contenteditable="false" draggable="true"><iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/85cb7aef-c9a6-4ef8-b1e2-47bc45441f6d?dark=false" class="fr-draggable" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true"></iframe></span></p><hr><p id="isPasted">This podcast is sponsored by <a href="https://www2.mouser.com/" rel="nofollow" target="_blank">Mouser Electronics</a>. &nbsp; &nbsp;&nbsp;</p><p><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1654599330909-Mouser-sponsor-1-a.jpg" style="width: 766px;" class="fr-fic fr-dib"></p><hr><h3 id="isPasted">EPISODE NOTES</h3><p>(0:50) -&nbsp;<a href="https://www.wevolver.com/article/ultrathin-fuel-cell-uses-the-bodys-own-sugar-to-generate-electricity" target="_blank">Glucose Fuel Cell</a></p><p>(13:46) - <a href="https://www.wevolver.com/article/researchers-develop-a-paper-thin-loudspeaker" target="_blank">Paper-thin Loudspeaker</a></p><hr><p id="isPasted">About the podcast:</p><p>Every day, some of the most innovative universities, companies, and individual technology developers share their knowledge on Wevolver. To ensure we can also provide this knowledge for the growing group of podcast listeners, we started a collaboration with two young engineers, Daniel Scott Mitchell &amp; Farbod Moghaddam who discuss the most interesting content in this podcast series.&nbsp;</p><p>To learn more about this show, please visit the&nbsp;<a href="https://www.wevolver.com/profile/the.next.byte" target="_blank">shows page</a>. By following the page, you will get automatic updates by email when a new show is published.</p><p>Be sure to give us a follow and review on&nbsp;<a href="https://podcasts.apple.com/nl/podcast/the-next-byte/id1548255861?l=en" rel="nofollow" target="_blank">Apple</a> podcasts,&nbsp;<a href="https://open.spotify.com/show/6lPPsRtegnivsRUEsQ09R7?si=IPMiah7xT_apJtPjqvXMlA" rel="nofollow" target="_blank">Spotify</a>, and most of your favorite podcast platforms!</p><p>Take a few seconds to leave us a review. It really helps!&nbsp;<a href="https://apple.co/2RIsbZ2" rel="nofollow" target="_blank">https://apple.co/2RIsbZ2&nbsp;</a>if you do it and send us proof, we&rsquo;ll give you a shoutout on the show.</p>

Silicon chip with 30 individual glucose micro fuel cells, seen as small silver squares inside each gray rectangle. Image: Kent Dayton

In this episode, we talk about why minimization of speakers and energy storage devices is crucial for the next generation of electronics and medical devices. 

Podcast: Nanometer Fuel Cells & Ultrathin Speakers

<p>This article was discussed in our <a data-saferedirecturl="https://www.google.com/url?q=https://www.wevolver.com/profile/the.next.byte&source=gmail&ust=1654577502725000&usg=AOvVaw17DYESu9H53oY-k8Bg1xYc" href="https://www.wevolver.com/profile/the.next.byte" id="isPasted" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;</p><p><span class="fr-video fr-deletable fr-fvc fr-dvb fr-draggable" contenteditable="false" draggable="true"><iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/85cb7aef-c9a6-4ef8-b1e2-47bc45441f6d?dark=false" class="fr-draggable" data-gtm-yt-inspected-9="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true"></iframe></span></p><p>The full article will continue below.</p><hr><p>This article was first published on <a href="https://news.mit.edu/2022/low-power-thin-loudspeaker-0426" id="isPasted" rel="noopener noreferrer" target="_blank">MIT News</a>. &nbsp;</p><hr><p id="isPasted">MIT engineers have developed a paper-thin loudspeaker that can turn any surface into an active audio source.</p><p>This thin-film loudspeaker produces sound with minimal distortion while using a fraction of the energy required by a traditional loudspeaker. The hand-sized loudspeaker the team demonstrated, which weighs about as much as a dime, can generate high-quality sound no matter what surface the film is bonded to.</p><p>To achieve these properties, the researchers pioneered a deceptively simple fabrication technique, which requires only three basic steps and can be scaled up to produce ultrathin loudspeakers large enough to cover the inside of an automobile or to wallpaper a room.</p><p>Used this way, the thin-film loudspeaker could provide active noise cancellation in clamorous environments, such as an airplane cockpit, by generating sound of the same amplitude but opposite phase; the two sounds cancel each other out. The flexible device could also be used for immersive entertainment, perhaps by providing three-dimensional audio in a theater or theme park ride. And because it is lightweight and requires such a small amount of power to operate, the device is well-suited for applications on smart devices where battery life is limited.</p><p>&ldquo;It feels remarkable to take what looks like a slender sheet of paper, attach two clips to it, plug it into the headphone port of your computer, and start hearing sounds emanating from it. It can be used anywhere. One just needs a smidgeon of electrical power to run it,&rdquo; says Vladimir Bulović, the Fariborz Maseeh Chair in Emerging Technology, leader of the Organic and Nanostructured Electronics Laboratory (ONE Lab), director of MIT.nano, and senior author of the paper.</p><p>Bulović wrote the paper with lead author Jinchi Han, a ONE Lab postdoc, and co-senior author Jeffrey Lang, the Vitesse Professor of Electrical Engineering. The research is published today in <em>IEEE Transactions of Industrial Electronics</em>.</p><h2><strong>A new approach</strong></h2><p>A typical loudspeaker found in headphones or an audio system uses electric current inputs that pass through a coil of wire that generates a magnetic field, which moves a speaker membrane, that moves the air above it, that makes the sound we hear. By contrast, the new loudspeaker simplifies the speaker design by using a thin film of a shaped piezoelectric material that moves when voltage is applied over it, which moves the air above it and generates sound.</p><p>Most thin-film loudspeakers are designed to be freestanding because the film must bend freely to produce sound. Mounting these loudspeakers onto a surface would impede the vibration and hamper their ability to generate sound.</p><p>To overcome this problem, the MIT team rethought the design of a thin-film loudspeaker. Rather than having the entire material vibrate, their design relies on tiny domes on a thin layer of piezoelectric material which each vibrate individually. These domes, each only a few hair-widths across, are surrounded by spacer layers on the top and bottom of the film that protect them from the mounting surface while still enabling them to vibrate freely. The same spacer layers protect the domes from abrasion and impact during day-to-day handling, enhancing the loudspeaker&rsquo;s durability.</p><p>To build the loudspeaker, the researchers used a laser to cut tiny holes into a thin sheet of PET, which is a type of lightweight plastic. They laminated the underside of that perforated PET layer with a very thin film (as thin as 8 microns) of piezoelectric material, called PVDF. Then they applied vacuum above the bonded sheets and a heat source, at 80 degrees Celsius, underneath them.</p><p>Because the PVDF layer is so thin, the pressure difference created by the vacuum and heat source caused it to bulge. The PVDF can&rsquo;t force its way through the PET layer, so tiny domes protrude in areas where they aren&rsquo;t blocked by PET. These protrusions self-align with the holes in the PET layer. The researchers then laminate the other side of the PVDF with another PET layer to act as a spacer between the domes and the bonding surface.</p><p>&ldquo;This is a very simple, straightforward process. It would allow us to produce these loudspeakers in a high-throughput fashion if we integrate it with a roll-to-roll process in the future. That means it could be fabricated in large amounts, like wallpaper to cover walls, cars, or aircraft interiors,&rdquo; Han says.</p><p><span class="fr-video fr-deletable fr-fvc fr-dvb fr-draggable" contenteditable="false" draggable="true"><iframe src="https://www.youtube.com/embed/pABxdxTuAY8?&wmode=opaque&rel=0&enablejsapi=1&origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" style="width: 767px; height: 438px;" data-gtm-yt-inspected-9="true" id="307239093"></iframe></span></p><h2 id="isPasted"><strong>High quality, low power</strong></h2><p>The domes are 15 microns in height, about one-sixth the thickness of a human hair, and they only move up and down about half a micron when they vibrate. Each dome is a single sound-generation unit, so it takes thousands of these tiny domes vibrating together to produce audible sound.</p><p>An added benefit of the team&rsquo;s simple fabrication process is its tunability &mdash; the researchers can change the size of the holes in the PET to control the size of the domes. Domes with a larger radius displace more air and produce more sound, but larger domes also have lower resonance frequency. Resonance frequency is the frequency at which the device operates most efficiently, and lower resonance frequency leads to audio distortion.</p><p>Once the researchers perfected the fabrication technique, they tested several different dome sizes and piezoelectric layer thicknesses to arrive at an optimal combination.</p><p>They tested their thin-film loudspeaker by mounting it to a wall 30 centimeters from a microphone to measure the sound pressure level, recorded in decibels. When 25 volts of electricity were passed through the device at 1 kilohertz (a rate of 1,000 cycles per second), the speaker produced high-quality sound at conversational levels of 66 decibels. At 10 kilohertz, the sound pressure level increased to 86 decibels, about the same volume level as city traffic.</p><p>The energy-efficient device only requires about 100 milliwatts of power per square meter of speaker area. By contrast, an average home speaker might consume more than 1 watt of power to generate similar sound pressure at a comparable distance.</p><p>Because the tiny domes are vibrating, rather than the entire film, the loudspeaker has a high enough resonance frequency that it can be used effectively for ultrasound applications, like imaging, Han explains. Ultrasound imaging uses very high frequency sound waves to produce images, and higher frequencies yield better image resolution. &nbsp;</p><p>The device could also use ultrasound to detect where a human is standing in a room, just like bats do using echolocation, and then shape the sound waves to follow the person as they move, Bulović says. If the vibrating domes of the thin film are covered with a reflective surface, they could be used to create patterns of light for future display technologies. If immersed in a liquid, the vibrating membranes could provide a novel method of stirring chemicals, enabling chemical processing techniques that could use less energy than large batch processing methods.</p><p>&ldquo;We have the ability to precisely generate mechanical motion of air by activating a physical surface that is scalable. The options of how to use this technology are limitless,&rdquo; Bulović says.</p><p>&ldquo;I think this is a very creative approach to making this class of ultra-thin speakers,&rdquo; says Ioannis (John) Kymissis, Kenneth Brayer Professor of Electrical Engineering and Chair of the Department of Electrical Engineering at Columbia University, who was not involved with this research. &ldquo;The strategy of doming the film stack using photolithographically patterned templates is quite unique and likely to lead to a range of new applications in speakers and microphones.&rdquo;</p><hr><p>&quot;Reprinted with permission of <a href="https://news.mit.edu/2022/low-power-thin-loudspeaker-0426" id="isPasted" rel="noopener noreferrer" target="_blank">MIT News</a>&quot;&nbsp;</p>

MIT researchers have developed an ultrathin loudspeaker that can turn any rigid surface into a high-quality, active audio source. The straightforward fabrication process they introduced can enable the thin-film devices to be produced at scale. Image: Felice Frankel

MIT engineers have developed a paper-thin loudspeaker that can turn any surface into an active audio source.

Researchers develop a paper-thin loudspeaker

<p id="isPasted">Bluetooth 5’s benefits are about much more than increased speed and extended range. Low energy advertising extensions are also a major enhancement.</p><p>Advertisements are used by devices to broadcast data and information that can be discovered and processed by observer devices. This means information can be broadcast to multiple devices at the same time, as opposed to Bluetooth connections, which only allow peer-to-peer communication.</p><h2>Improvements in Bluetooth 5</h2><p>The release of the Bluetooth 5 specification promised new functionality for connectionless services such as location-relevant information and navigation. By adding significantly more capacity to advertising packets, Bluetooth 5 aims to quicken the deployment of beacons and location-based services to users around the world.</p><p>Advertising extensions in Bluetooth 5 provide the capability to offload advertising data from the three traditional advertising channels to the full set of data channels for more frequency diversity. More efficient use of the 2.4 GHz band should enable developers to increase the rate of advertised packets, as well as utilize the new PHY modes, paving the way for better streaming and beacon solutions.</p><p>All these LE PHY’s supported by Bluetooth 5 can be used for advertisements with the introduction of advertising extensions:</p><ul><li>LE 1M PHY: 1 Mb/s bit rate, 1 Msym/s symbol rate. Each bit maps to a single radio symbol. The same PHY as used in Bluetooth 4.0.</li><li>Coded PHY: 1 Mb/s bit rate, 500 or 125 ksym/s symbol rate. Each bit is coded into 2 or 8 bits using a forward error correction algorithm to provide higher tolerance for bit errors, resulting in improved range.</li><li>LE 2M PHY: 2 Mb/s bit rate, 2 Msym/s symbol rate. Doubles the symbol rate to increase the speed, at a small cost to range.</li></ul><h2>Extended Advertisements</h2><p>In Bluetooth 4.0, all advertising was done on just three channels. Bluetooth 5 improves this mechanism by allowing a small header packet sent on the three primary advertising channels to point to a larger payload sent at a later time on one of the 37 data channels.</p><p>This removes the need to duplicate the data payload on all three advertising channels, while allowing considerably more advertising data in the area before running into coexistence issues.</p><p>The specification for extended advertisements in Bluetooth 5 is almost as large as the entire original Bluetooth 4.0 specification. There are some key differences to understand before delving into development, including:</p><ul><li>A single advertising packet can hold up to 255 bytes of data, up from 37 in Bluetooth 4.0</li><li>Advertising packets can now be chained together, allowing for even larger beacon payloads than with a single packet (a chain can hold a maximum of 1650 bytes)</li><li>Advertising packets can be sent periodically, allowing observers to lock on to a stream of advertised packets</li><li>Periodic advertisements can be combined with chained packets, allowing an even higher overall data throughput</li></ul><p>Because older devices that don’t support Bluetooth 5 will not be able to discover extended advertisements, an advertising set with legacy advertising PDUs for older scanning devices should also be used, at least until Bluetooth 5 supported hardware is commonplace in the market.</p><h2>Bluetooth Advertising and beacons</h2><p>Beacons can now broadcast more data and allow for a better user experience. Connectable devices can also utilize this to send more data and allow connections on the secondary advertising channels (which can help avoid interference and noise from other devices broadcasting on the primary channels).</p><p>Although beacon applications stand to benefit most from these extended advertisements, there will be a wait involved until relevant devices such as smartphones and tablets fully support Bluetooth 5 advertising extensions. It's a wait that will be worthwhile, as there is a big potential for new applications and for the use of Bluetooth in more markets.</p><h2>Beyond Bluetooth 5</h2><p>The development of the Bluetooth standard didn’t stop with version 5, and subsequent updates have brought new features and improvements.</p><p>The 5.1 version focused primarily on adding direction-finding support to serve the indoor positioning use case where Bluetooth beacons need to be located with a high degree of accuracy.</p><p>The headline feature of version 5.2 was support for LE Audio, which improves the existing audio support in Bluetooth, aiming to increase battery life, sound quality, and feature set for Bluetooth audio applications.</p><p><br>Common for both of these features is that they leverage the advertising extension functionality added in version 5 in new ways. Depending on the use case, both direction finding and LE Audio can be used either in a broadcasting or a connected mode. When broadcasting is needed, advertising extensions will provide the data throughput and flexibility required by these two features.</p><p>Future updates to the specification will likely find even more ways to utilize advertising extensions, making this an integral part of many different Bluetooth products.<br><br><em>This is an updated version of an article first published in December 2017.</em></p><hr><p>This article was first published on Nordic's&nbsp;<a href="https://blog.nordicsemi.com/getconnected" target="_blank" rel="nofollow" id="isPasted"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" rel="nofollow" target="_blank">Get Connected Blog</a>. </p>

Bluetooth 5’s benefits are about much more than increased speed and extended range. Low energy advertising extensions are also a major enhancement.

Bluetooth 5 Advertising Extensions

<p id="isPasted">People living with disabilities don't want special treatment; they want equal opportunity. The ability to act independently of, and at the same time connect with, others when moving, communicating, learning, working, and socializing.</p><p>Technology is making this increasingly viable, as assistive and adaptive technologies create a more accessible world for people living with a range of disabilities, including limb differences, motor neuron disease, as well as the blind and deaf.</p><p>Much of this development has focused on smartphones and computers, but wireless IoT technology also plays its role.</p><h2>The world around us</h2><p>Connected technologies such as environmental sensors, smart objects, and wearables are powerful tools. They can provide various inclusive and assistive information services in near real-time and connect people with disabilities with their work, home, and other environments:</p><ul><li>Indoor and outdoor wayfinding solutions employing computer vision, augmented reality, and wireless optical communications are assisting the visually impaired navigate their way from home to work and back again</li><li>Clothing embedding haptic stimulation sensors can enable the deaf to 'feel the beat' of a musical performance</li><li>Robotic limbs and bionic exoskeletons are giving the wearer control of their environment and the ability to stand and walk</li></ul><h2>Wearables for tackling MND</h2><p>Nordic Semiconductor has been working closely with customers who develop wireless solutions for those living with a disability. One such company is Control Bionics, whose wearable assistive technology offers people with amyotrophic lateral sclerosis (ALS)—also known as motor neuron disease (MND)—the ability to communicate despite paralysis or loss of speech. The small, non-invasive sensor is placed on the skin over the muscle chosen to be the switch. When the user attempts to move that muscle, the device interprets the signals sent from the brain to the muscle and uses those signals to control a paired computer, tablet, or smartphone wirelessly.</p><h2>Bluetooth LE bionic arms</h2><p>Another example is U.S. non-profit organization, Limbitless Solutions, which creates personalized bionic arms for children suffering from limb differences. The prosthetic limbs employ electromyographic (EMG) sensors to pick up signals generated by muscle movements in the wearer's upper arm. The forearm section of the bionic arm contains a battery pack that powers the motors controlling the different movements, while the hand unit includes the core electronics and motors for the fine control of the individual fingers. Bluetooth LE connectivity enables set-up, adjustment, and monitoring of the arm from a smartphone app, for example, to precisely determine the degree of muscle flexing required to generate a certain force in the fingers, and to help the child learn how to manipulate their new arm.</p><h2>Next-gen connectivity solutions</h2><p>Bluetooth LE wireless connectivity and next-generation SoCs play an essential role in ensuring the viability of these and other technologies for end-users living with disabilities. They provide a low latency wireless link to a smartphone or tablet for ease of control, and also low power consumption in an ultra-miniaturized form factor.</p><p>Avoiding having to charge our devices frequently is a significant advantage to any user, and none of us want a clunky wearable that is uncomfortable to wear. Still, the benefits are more fundamental when that device is in near-constant use or is relied upon for daily life. For example, bionic arms must be comfortable, lightweight, and easy to use, particularly for children. Smartwatches for the blind, meanwhile, must be able to last at least a full day on a single charge.</p><p>As these assistive technologies become more sophisticated and ambitious in their scope, wireless SoCs will need to keep pace. Nordic's new nRF53 Series has been designed to meet the likely requirements of developers in the future. It offers a new flexible, dual-processor hardware architecture, low power, and the ability to support miniaturized machine learning, edge processing, and LE Audio.</p><h2>The promise of LE Audio</h2><p>LE Audio, for instance, has the potential to significantly improve the experience of users of hearing aids and hearing implants by supporting a feature called Audio Sharing. Thanks to LE Audio, people with hearing loss will be able to realize the same benefits of Bluetooth audio enjoyed by users of standard Bluetooth headphones and earbuds, including wireless calling, listening, and watching. Audio Sharing will enable an advanced new type of Assistive Listening Systems with higher audio quality and greater privacy that avoids the challenges of sound quality, spill-over (magnetic interference created by multiple hearing loops in close proximity), and costs of current systems.</p><p>Wireless technology exists now, and it can provide disabled users with the ability to participate in all aspects of life on more equal terms than previously possible.&nbsp;</p><hr><p>This article was first published on Nordic's&nbsp;<a href="https://blog.nordicsemi.com/getconnected" target="_blank" rel="nofollow" id="isPasted"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" rel="nofollow" target="_blank">Get Connected Blog</a>. </p>

People living with disabilities don't want special treatment; they want equal opportunity. The ability to act independently of, and at the same time connect with, others when moving, communicating, learning, working, and socializing.

Connected IoT tech promotes accessibility for all

<p id="isPasted">Despite specific industries experiencing slowdowns caused by the Covid-19 pandemic, projections in the Bluetooth technology market are optimistic through the remainder of 2021 and beyond.</p><p>Annual shipments of Bluetooth-enabled devices are expected to grow at a compound annual growth rate (CAGR) of 10 percent over the next five years, reaching 6.4 billion in 2025. More specifically, 70 percent of these shipments in 2025 will be peripheral devices such as earbuds, wearables, sensors, and smart lights – clearly outpacing platform-device shipments (for example, phones, tablets, and PCs) by three to one.</p><p>These forecasts headline the Bluetooth Special Interest Group's (SIG) 2021 <a href="https://www.bluetooth.com/bluetooth-resources/2021-bmu/" rel="noopener" target="_blank">Bluetooth® Market Update</a>, based primarily on analysis by ABI Research, which also points to an impressive upturn for different Bluetooth technologies across various verticals.</p><h2>Market shifts further towards Bluetooth LE</h2><p>Bluetooth Classic has peaked, and dual-mode devices (supporting both Bluetooth Classic and LE capabilities) are rising. Still, current trends suggest a marked increase in Bluetooth LE-only solutions. Shipments of these single-mode devices are expected to triple over the next five years, states the latest Bluetooth SIG report.</p><p>In particular, <a href="https://www.nordicsemi.com/Products/Bluetooth-Low-Energy?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">Bluetooth LE</a> will prove a dominant protocol among the global consumer electronic devices sector. The anticipation is that 96 percent of devices will include Bluetooth LE by 2025, primarily due to its prevalence in phones, tablets, and computers. A range of new features supported by Bluetooth LE also contributes to its forecast growth.</p><h2>Bluetooth LE Audio announces its arrival</h2><p>Over the past year, Bluetooth audio streaming has accounted for 1.3 billion shipments in 2021. The forecast for this solution area is to achieve 1.5 x growth from 2021 through 2025, reaching 1.7 billion annual shipments in 2025. Most of these shipments comprise headphones, with 633 million transported in 2021 alone. Demand for Bluetooth speakers will see shipments increase from 350 million in 2021 to 423 million in 2025.</p><p>But the launch of <a href="https://www.nordicsemi.com/Products/Bluetooth-LE-Audio?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">Bluetooth LE Audio</a> will take global Bluetooth audio to another level. Bluetooth LE Audio enhances Bluetooth Classic audio by providing higher quality audio streaming with longer battery life for speakers and headphones. And the prevalence of Bluetooth LE means Bluetooth LE Audio is likely to lead the way in audio streaming worldwide, with earbuds shipments alone forecast to see 3.4 x growth to 521 million by 2025.</p><p>Yet this is only the beginning of what Bluetooth LE Audio can make possible. The technology will include the Bluetooth Audio Sharing feature, enabling use cases where, for example, multiple headphones connect to a single audio stream. Bluetooth Audio Sharing might make public audio more accessible for the 1.5 billion people worldwide living with some form of hearing loss (figures from the World Health Organization). Utilized at conference centers, airports, and other public venues, it can form low-cost assistive listening systems by transmitting the audio stream directly to in-ear Bluetooth hearing assistance devices. More than 92 million such devices are expected to ship annually by 2024, according to Juniper Research.</p><p>Bluetooth LE Audio demands high-end processing capabilities. Nordic's <a href="https://www.nordicsemi.com/Products/nRF5340?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">nRF5340 SoC</a> includes a new, flexible dual-processor hardware architecture with advanced security features designed to meet the Bluetooth LE multi-stream synchronized audio requirements.</p><h2>High-end processing supports advanced audio</h2><p>Bluetooth LE Audio is set to change the way we listen, but what drives the technology itself? Bluetooth LE Audio works through compressing the necessary data using an algorithm known as a Low Complexity Communication Codec (LC3) to reduce the throughput. Once received, another algorithm decompresses the data, allowing users to stream the same audio quality at reduced bitrates. This design also makes the creation of untethered earphones easier, as both can receive the stream with synchronized playback (through isochronous channels) instead of the old point-to-point stream.</p><h2>Bluetooth Location Services</h2><p>The Bluetooth Location Services market is also moving in the right direction. Expectations for the segment are to exhibit healthy medium-term expansion, with 32 percent CAGR in annual device shipments from 2021 to 2025.</p><p>According to the report, retail is the vertical taking the most significant advantage of Bluetooth Location Services, with 66 percent of all implementations currently supporting retail use cases. At the same time, 79 percent of Bluetooth Location Services solutions include indoor navigation properties. For example, 136 million Bluetooth RTLS tags and personal trackers will ship in 2021, the report claims, with 4 x growth in asset tracking tag shipments and 5 x growth in Bluetooth healthcare location services implementations predicted by 2025. The effects of the pandemic primarily spur the latter.</p><p>As wireless innovation continues in the face of recent challenges, resilient Bluetooth technology is powering its way into the future.</p><hr><p>This article was first published on Nordic's&nbsp;<a href="https://blog.nordicsemi.com/getconnected" target="_blank" rel="nofollow" id="isPasted"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" rel="nofollow" target="_blank">Get Connected Blog</a>. </p>

Despite specific industries experiencing slowdowns caused by the Covid-19 pandemic, projections in the Bluetooth technology market are optimistic through the remainder of 2021 and beyond.

Continued growth forecast for resilient Bluetooth and LE Audio technology

<p>USound currently offers two MEMS loudspeakers that are part of the Ganymede series: Adap UT-P2019 and Achelous UT-P2018. Adap is optimized towards maximum acceleration, making it ideal for free-field applications, whereas Achelous is optimized towards maximum excursion, making it especially suitable for occluded-ear applications. Therefore, USound MEMS loudspeakers can be evaluated in both acoustic domains: baffle and coupler conditions. For baffle conditions, the IEC 60268-5 standard is used, while for coupler conditions, the relevant standard is the IEC 60318-4, formerly known as 60711, or simply &ldquo;711&rdquo;. For both setups, proprietary measurement adapters are used to fit USound speakers to the standardized setup. Using the adapters, it is possible to achieve the results shown on the Adap and Achelous datasheets. Measurements with the Carme Box UJ-R1020 can also assess the speakers&rsquo; performance even if they lead to slightly different results. In this article, we will show several possibilities to perform the measurements and the differences between those methods.</p><h2 id="isPasted"><strong>BAFFLE MEASUREMENT (IEC&nbsp;60268-5)</strong></h2><p>To measure the loudspeaker in a<strong>&nbsp;</strong>baffle<strong>,</strong> it is necessary to place the MEMS speaker inside the measurement adapter. The following picture shows a drawing of the proprietary adapter used by&nbsp;USound.</p><figure><img data-fr-image-pasted="true" src="https://lh4.googleusercontent.com/J5XLouoWSuShn2kNsrXZlX7cw0jFZl5jQrjSL1EdbaFMATh5sfK1oVCd4B3D4nkMQWXAM0cgZFBTtXlW445rnkRFSDvZ_OB4v7qyiR53GGHtAIHN67NhwYzjFeitd6NnvWBOIlvs" alt="" class="fr-fic fr-dii"></figure><p>The electronic connection is achieved using pogo pins that press against the pads on the back of the loudspeaker. A gasket is placed in front of the speaker for sealing purposes, and an opening in the baffle enables the speaker to radiate towards the microphone, which is placed at a 10 cm distance from the baffle (as per the IEC 60268-5 standard). The SPL and THD results measured with this setup can be found on the&nbsp;<a href="https://www.usound.com/technical-documentation/" target="_blank">Adap UT-P2019&nbsp;datasheet</a>.</p><h3><strong>COUPLER MEASUREMENT (IEC&nbsp;60318-4)</strong></h3><p>For coupler measurements, a coupler adapter was designed to place the speaker close to the coupler without introducing additional resonances. This was obtained using a port of 3.6 mm diameter and 1.5 mm length (with an additional gasket of 0.5 mm, compressed to 0.3 mm). By using these dimensions, any emerging resonance is guaranteed to fall above the audible frequency range (&gt;20 kHz). With the use of USound&rsquo;s coupler adapter, the measurement can be performed without the earmold adapter. The SPL and THD results measured with this setup can be found on the&nbsp;<a href="https://www.usound.com/technical-documentation/" target="_blank">Achelous UT-P2018 datasheet.&nbsp;</a></p><h2>MEASURING MEMS SPEAKERS WITH THE CARME UJ-R1020 SPEAKER&nbsp;BOX.</h2><p>The two methods mentioned above require the use of proprietary coupler adapters. Another possibility to measure USound loudspeakers is by using the Carme UJ-R1020 speaker box. With a back volume of 100 mm&sup3;, it provides the necessary sealing to avoid an acoustic short circuit. It offers a convenient way to connect USound MEMS speakers to USound&lsquo;s linear amplifier Amalthea UA-R3010 or to the Helike UA-E3010 development board. With the Carme speaker box, both measurements in free-field and measurement on an artificial ear are&nbsp;possible.</p><h3><strong>MEASUREMENT WITH CARME BOX IN&nbsp;FREE-FIELD</strong></h3><figure><img data-fr-image-pasted="true" src="https://lh4.googleusercontent.com/U5uzyqnZLWRpXlwc1Gtv94bUBUlLcpX3s9UJe1VlHTHF_9lVpc0SFpNX6beQXZZ9-pAwYi3JtRSSDJryAP7TG87oB2c9DlVplTXJkcbf4DDb6Be2K3hJUxZLcoDwHzkSkSeDYsp0" alt="" class="fr-fic fr-dii"></figure><p>The box must be placed in a reflection-free space such as an anechoic chamber and pointed towards the microphone. Since no baffle is used in this setup and a back volume is introduced, the frequency response will be different from the results present on the Adap datasheet. Due to the missing baffle, the SPL will be ~6 dB lower below resonance frequency. The following graph compares the results obtained with the USound coupler adapter and with Carme&nbsp;Box.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-1024x409.png" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-1024x409.png 1024w, https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-300x120.png 300w, https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-768x307.png 768w, https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-1536x614.png 1536w, https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box.png 2048w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="height: 300px;"><figcaption>Adap UT-P2019 SPL measurement in the Carme UJ-R1020 test box in free field</figcaption></figure><h4><strong>Measurement with Carme Box in a&nbsp;coupler</strong></h4><p>For coupler measurements, two setups are possible: with or without the earmould adapter. Therefore, the Carme UJ-R1020 box can be placed directly on the base part of the coupler or the earmould adapter, as shown in the following picture.&nbsp;</p><figure><img data-fr-image-pasted="true" src="https://lh4.googleusercontent.com/cW1VA3oRLSVzuCXuaaqTYz517VDH1PopwuEFtUNawEpoylpEmP7GkF3flRI7wmd1ptO-tgEIjBXap-lFYdmIcyO1_1njwZiwsStlFh9orP6DNuDWjewiBWte62oKzpxwD4WZtR2J" alt="" class="fr-fic fr-dii"></figure><figure><img data-fr-image-pasted="true" src="https://lh4.googleusercontent.com/iJ9Fsql8g_vE7FFd00DiJcy4zhFNG_TelJwJ5L79xjxKP_lA99pWIZ_1rv9uxcwK58lwGF_mtHWCZGEIgnG5L8MY-RKepYMYQ3ZzBQlYZcHrGkC6ZB5YCAKcELRQb6YyQ4DDF-Y1" alt="" class="fr-fic fr-dii"></figure><p>In both cases, to seal the air volume between the box and the coupler, it is necessary to apply sealing material (blu-tack, putty) between the two parts. Since the dimensions are not the same as with the USound coupler adapter, some differences will emerge.&nbsp;</p><p><strong id="isPasted">Recommended reading:&nbsp;</strong><span style="background-color: transparent;"><a href="https://www.wevolver.com/article/why-usound-mems-speakers-outperform-electrodynamic-and-balanced-armature-micro-speakers" rel="noopener noreferrer" target="_blank">Why USound MEMS speakers outperform electrodynamic and balanced armature micro speakers</a></span></p><p>Nevertheless, the results will also be relevant to assess the MEMS speaker&rsquo;s performance. A comparison between the results obtained from the two methods mentioned above and the setup with USound&rsquo;s coupler adapter is shown in the following graph.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/Achelous-UT-P2018-SPL-measurement-in-the-Carme-UJ-R1020.png" alt="Achelous UT-P2018 SPL measurement in the Carme UJ-R1020" srcset="https://www.usound.com/wp-content/uploads/2021/07/Achelous-UT-P2018-SPL-measurement-in-the-Carme-UJ-R1020.png 1003w, https://www.usound.com/wp-content/uploads/2021/07/Achelous-UT-P2018-SPL-measurement-in-the-Carme-UJ-R1020-300x124.png 300w, https://www.usound.com/wp-content/uploads/2021/07/Achelous-UT-P2018-SPL-measurement-in-the-Carme-UJ-R1020-768x316.png 768w" sizes="(max-width: 1003px) 100vw, 1003px" class="fr-fic fr-dii" style="height: 300px;"><figcaption>Achelous UT-P2018 SPL measurement in the Carme UJ-R1020 speaker-test box</figcaption></figure><p><br></p>

USound MEMS loudspeakers can be evaluated in both acoustic domains: baffle and coupler conditions. 

How to measure USound MEMS loudspeakers

<p id="isPasted">Most consumer electronics nowadays use traditional electrodynamic speakers. They consist of a magnet, a voice coil, a diaphragm and a support structure/enclosure. This working principle limits the minimum height that can be achieved with such a loudspeaker. The diaphragm’s suspension solely controls the mechanical behaviour, as electrodynamic microspeakers typically lack the centering spider of larger&nbsp;loudspeakers.</p><p>In this article we will demonstrate how MEMS-based microspeakers outperform the traditional voice coil-based microspeakers, and how manufacturers can benefit from a more reliable component to build more ergonomic and unique audio devices.&nbsp;</p><p>The trend in MEMS sensors and transducers is to replace the complete system with a silicone equivalent. While this is a viable solution for many applications, the physics of generating sound demands a more sensible approach. To generate sound, an important factor is the effective radiating area – the higher the area, the more sound is produced. Silicon processes scale inversely with size, however, and MEMS technology gets cheaper the smaller the silicon elements are. A second factor is the movement of the radiating area: The more the area moves, the more sound is being produced. With silicon being a stiff material with inherently high resonance frequencies, this works fine for ultrasonic applications but is difficult to apply towards audio&nbsp;frequencies.</p><p>USound’s innovation is to separate the radiating area and the driving elements into two components: the diaphragm and the MEMS motor. This allows to make the MEMS motor small, reaping all the cost benefits of smaller silicon elements while not sacrificing effective radiating surface area. It also allows optimization of the MEMS elements for force as opposed to large surface&nbsp;area.</p><p>Combining the advantages of semiconductor processes with larger surface areas is the reason why USound MEMS loudspeakers outperform other comparable concepts: the use of a diaphragm allows for smaller MEMS elements while retaining a larger acoustically effective area to produce&nbsp;sound.</p><p>Comparing MEMS speakers to traditional electrodynamic voice-coil or balanced armature loudspeakers, USound’s speakers are superior in three categories:</p><h3 id="isPasted">SYSTEM&nbsp;INTEGRATION</h3><p>Specific versions of USound MEMS loudspeakers can be used with reflow soldering. This allows integration into fully automated SMT assembly lines and many other&nbsp;environments.</p><p>MEMS loudspeakers are capacitive in nature, which means that the energy is not dissipated as heat. MEMS loudspeakers heat up significantly less than electrodynamic loudspeakers during use, which means that surrounding sensors are less&nbsp;affected.</p><h3>FORM&nbsp;FACTOR</h3><p>Silicon processes result in inherently thin systems. The MEMS motor in USound loudspeakers is less than half a millimeter thick, an order of magnitude thinner than electrodynamic loudspeakers. The fact that neither a heavy voice coil nor a heavy magnet are used results in a much lower weight of the loudspeaker as&nbsp;well.</p><p>The image below shows how much less space a MEMS loudspeaker (right) takes up compared to a traditional 6 mm dynamic loudspeaker (left) commonly used in modern TWS&nbsp;earbuds.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/03/USound-MEMS-speaker-solution-for-TWS-vs-voice-coil-solution-for-tws-2.png" alt="" class="fr-fic fr-dii" style="width: 500px;"></figure><h3>SOUND&nbsp;QUALITY</h3><p>Compared to voice-coil-base electrodynamic microspeakers, USound MEMS loudspeakers benefit from the stabilizing effect of the piezo motor, which not only provides the driving force but also acts similar to the centering spider of larger loudspeakers, keeping the movement more linear and controlled. The speed and precision of a linear actuator such as a MEMS piezo element are higher than a voice coil, which allows for&nbsp;<a href="https://www.usound.com/usounds-mems-speakers-extreme-bandwidth-technology/" target="_blank">higher bandwidth</a> and more accurate reproduction of high frequencies. At the same time, the bass can be tuned from linear (preferred by many audiophiles) to a significant boost (preferred by some people and anything in between. This means that a single MEMS loudspeaker can be used for the whole audible frequency range instead of using multiple&nbsp;speakers.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/03/USound-MEMS-speakers-Bass-boost.png" alt="" class="fr-fic fr-dii" style="width: 700px;"></figure>

In this article, we will demonstrate how MEMS-based microspeakers outperform the traditional voice coil-based microspeakers, and how manufacturers can benefit from a more reliable component to build more ergonomic and unique audio devices. 

Why USound MEMS speakers outperform electrodynamic and balanced armature micro speakers

<p id="isPasted">Most components in consumer electronics are silicon-based. The last component that is still manufactured traditionally is the loudspeaker — until now. USound is leading the revolution of the global speaker market, being the first company to introduce MEMS loudspeakers to the mass market. The thin form factor and wide bandwidth of USound MEMS speakers enable miniaturization of the audio module in wearables, hearables, smartphones, and smart devices in general. With traditional technology, this would be impossible without compromising the audio&nbsp;quality.</p><p>So what are the inherent advantages of USound MEMS loudspeakers compared to conventional electrodynamic and balanced armature&nbsp;speakers?</p><p><br></p><h3><strong>SMALLER&nbsp;SIZE</strong></h3><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/article.jpg" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/article.jpg 1024w, https://www.usound.com/wp-content/uploads/2021/07/article-300x132.jpg 300w, https://www.usound.com/wp-content/uploads/2021/07/article-768x338.jpg 768w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="width: 800px;"></figure><p>The main size advantage from USound MEMS loudspeakers comes from the thickness or lack thereof. In traditional electrodynamic loudspeakers, there is a lower limit to the size of the voice coil and magnet assembly. And while rare-earth magnets (especially neodymium magnets) allow the use of smaller magnets while retaining the same sound pressure level output, they still dominate the geometry and impose a lower limit to the size of the loudspeaker. Simply put: traditional microspeakers consist mostly of the magnet. They can not be miniaturized further, as the magnet can not shrink without losing sound&nbsp;output.</p><p>Replacing the voice coil + magnet assembly with a MEMS motor removes this limit. The thickness of a MEMS motor is essentially zero compared to a coil + magnet. In the case of MEMS loudspeakers, the loudspeaker thickness is limited only by how far the motor needs to excurse. This allows USound MEMS loudspeakers to be as thin as 1.3&nbsp;millimeters.</p><p>This reduced thickness frees up more real estate for other components, such&nbsp;as</p><ul><li>A larger battery (higher battery life)</li><li>Accelerometers (headtracking)</li><li>Additional microphones (beamforming, noise cancelling)</li><li>UHF sensor (“find my device”)</li><li>Infrared-sensors (ear detection)</li><li>Pulse-oximeter (health sensoring)</li></ul><p><br></p><h3>PCB-BASED</h3><p>Since USound MEMS loudspeakers are PCB-based, they can easily be combined with additional SMD components to form an audio module. They can be mounted to a PCB via reflow soldering or conductive glue. This allows for easy outsourcing of acoustic design, rapid prototyping, and evaluation and, thus, a faster time to market.&nbsp;</p><p><br></p><h3>NON-FERROMAGNETIC&nbsp;MATERIALS</h3><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/MEMS-speakers-1.jpg" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/MEMS-speakers-1.jpg 1024w, https://www.usound.com/wp-content/uploads/2021/07/MEMS-speakers-1-300x103.jpg 300w, https://www.usound.com/wp-content/uploads/2021/07/MEMS-speakers-1-768x263.jpg 768w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="width: 800px;"></figure><p>On request, USound MEMS speakers can be manufactured without ferromagnetic materials with zero tradeoffs in acoustic performance. This allows the use of these loudspeakers in areas with strong magnetic fields, i.e., to communicate with the patient inside an MRI&nbsp;machine.</p><p><br></p><h3><strong>SMALLER MOVING MASS, THEREFORE LOWER&nbsp;VIBRATIONS</strong></h3><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/article3.jpg" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/article3.jpg 1024w, https://www.usound.com/wp-content/uploads/2021/07/article3-300x132.jpg 300w, https://www.usound.com/wp-content/uploads/2021/07/article3-768x338.jpg 768w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="width: 800px;"></figure><p>Ideally, the only part of the loudspeaker that moves should be the diaphragm; if the ratio of diaphragm mass vs. total mass is too high, the casing of the loudspeaker will vibrate as well. These unwanted mechanical vibrations can cause solid-borne sound to enter microphones in the immediate vicinity. If the signal of these microphones is used to feed the loudspeaker (e.g., in an earphone in transparency mode or in a hearing aid), this will cause a feedback loop, typically audible as a highly irritating, screeching sound. Due to the absence of a heavy voice coil, USound MEMS speakers are much lighter and produce significantly fewer mechanical vibrations. This is important not only for hearing aids but also for modern TWS earphones with “transparency”/”hearthrough” mode, where the recording of the microphone is being played through the loudspeaker on the same&nbsp;device.</p><p><br></p><h3>NO ELECTROMAGNETIC&nbsp;RADIATION</h3><p>Conventional speakers rely on the Lorentz force, where a change in the electric field, by applying a voltage to the coil while it is suspended in a magnetic field, imposes a force on said coil and causes it to move. The induced change in the electromagnetic field is a form of electromagnetic radiation, which will radiate into the surrounding. Some types of sensors can easily be disturbed by this unwanted electromagnetic pollution. USound MEMS loudspeakers, on the other hand, rely on the piezoelectric principle, which causes no electromagnetic radiation. This eliminates the need for any magnetic shielding in mobile devices between speakers and other sensitive parts (like&nbsp;sensors).</p><p><br></p><h3>NO HEAT&nbsp;GENERATION</h3><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/low-heat-generation-2.jpg" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/low-heat-generation-2.jpg 1024w, https://www.usound.com/wp-content/uploads/2021/07/low-heat-generation-2-300x103.jpg 300w, https://www.usound.com/wp-content/uploads/2021/07/low-heat-generation-2-768x263.jpg 768w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="width: 800px;"></figure><p>While the electric impedance of conventional microspeakers has a reactive component caused by the coil, the impedance of the whole system is normally dominated by the resistive component of the length of wire that forms said coil. This means that the electrical energy is mostly converted into thermal energy as it dissipates across the ohmic resistance. In typical mobile phone speakers, the coil heats up to over 70&nbsp;°C.</p><p>However, in USound MEMS loudspeakers, the electric impedance is determined solely by the capacity between the two electrodes of the MEMS element. The impedance is therefore purely capacitive and has virtually no resistive component, meaning that the energy does not dissipate, and a much smaller percentage is converted to thermal energy. This means that less heat is generated. Typically the temperature of the hottest part of a USound MEMS loudspeaker is not significantly above room temperature. Like the reduced EMI, this causes less disturbance for surrounding sensors (especially infrared sensors) and also reduces the wear and tear of other components that are sensitive to temperature (e.g., batteries). The electric impedance being purely capacitive also means that the electric energy can be “reused” by pulling it back out of the loudspeaker, so to speak. This lowers the total power consumption of the&nbsp;loudspeaker.</p><p><br></p><h3>SUMMARY</h3><p>USound MEMS loudspeakers offer many benefits over conventional&nbsp;loudspeakers.</p><ul><li>Smaller size</li><li>Easier integration</li><li>Easier modularization</li><li>Direct PCB mounting</li><li>No ferromagnetic materials</li><li>Less unwanted vibrations</li><li>No EMI</li><li>No heat generation</li></ul><p>And all these benefits come while still fulfilling the requirements for audio performance. There is no need to make a tradeoff in the actual sound — but you can now build high-end audio products with additional functionalities.</p>

Most components in consumer electronics are silicon-based. The last component that is still manufactured traditionally is the loudspeaker — until now.  Loudspeakers using USound MEMS technology offer a multitude of inherent advantages, compared to traditional ED or BA speakers.