It seems more clear every day that while wireless audio streaming remains the largest Bluetooth solution application area by far, LE Audio is taking a bit longer than expected and what is so far included in the specifications - while fitting the requirements written more than a decade ago, particularly by the hearing aid companies - is no longer what consumers will expect as progress.

Technically, there's no doubt that LE Audio - and particularly the Low Complexity Communication Codec (LC3) codec - will help solve many of the current problems and limitations of Bluetooth audio, but it's clearly not something that can be explained to consumers, or that will excite consumers in any way. Thanks to Apple, consumers are now used to seeing significant evolution in technology, almost on a yearly - relentless - pace. Explaining the benefits of LC3 to consumers involves explaining that the SBC codec was very bad, that what they have been actually listening to when not using SBC is AAC (which many in the industry don't even like to point out), and that basically the future is about “less water pressure in the shower" - which is basically what LC3 means for any user who cares about audio quality.

So, what the Bluetooth SIG recently tried to do is to inject some enthusiasm back into the pre-pandemic Bluetooth LE Audio announcement, with "new" Bluetooth capabilities in Auracast broadcast audio. Announced on July 8, Auracast seemed to me somewhat dubious and a pure marketing reboot of existing promises for a specification that has been delayed now for two-and-a-half years.

When the Bluetooth SIG announced LE Audio at CES 2020, the upcoming specification promised two major benefits: the new LC3 codec to provide higher audio quality at the same or lower bit rates and the same battery life, AND Broadcast Audio, enabling personal and location-based Audio Sharing. Now the Bluetooth SIG announced that the Audio Sharing features would be offered under a new "brand" as Auracast broadcast audio.

With this announcement, basically the Bluetooth SIG is admitting that after two years of preliminary work (before CES 2020) plus two-and-a-half years of work during the global pandemic, the specifications are still being worked out, and that the audio broadcasting capability based on Bluetooth technology is still "upcoming."

While the LC3 codec was available in 2020, the actual details of technical implementation for the new use cases are still being worked out. As SAR Insight & Consulting predicted in 2020, "As the Bluetooth market is already well established, LC3 is forecast to have a fast and smooth adoption, reaching over 77% of all A2DP-enabled devices by 2025. This will leave only 30% growth left before it reaches the same level as SBC. SBC will remain stable until 2022. At this point it will begin to slowly drop off, being replaced by LC3. In the long run, this drop off will increase until nearly all products use LC3 exclusively."

Those predictions are probably now off by two years because of the pandemic. So, there was a good reason to refresh the LE Audio marketing. As the Bluetooth SIG describes, the new (trademarked) Auracast broadcast audio "technology" enables an audio transmitter, such as a smartphone, laptop, television, or public address system to broadcast audio to an unlimited number of nearby Bluetooth audio receivers, including speakers, earbuds, or hearing devices.

Basically, this is the same functionality that has been available for many years using the SKAA Wireless Audio proprietary technology developed by Canadian firm Eleven Engineering and today available in numerous products. Those more recent ones are able to receive audio sources via Wi-Fi or Bluetooth and then transmit reliably at CD-quality to multiple receivers using SKAA. The technology is now seeing a resurgence in DJ and party-speaker applications where dedicated receivers are not an issue. SKAA was always very poorly marketed, otherwise it could have completely dominated the space, at least for professional audio applications.

Other earlier attempts to implement the "party" mode functionality over Bluetooth have been successfully demonstrated by companies such as Tempow, meanwhile acquired by Google. Their first product - the Tempow Audio Profile (TAP) - was an updated Bluetooth protocol allowing any Bluetooth chip to stream audio to multiple Bluetooth audio outputs simultaneously. And of note, it was a 100% software solution and worked with any brand of Bluetooth speaker on any chip.

Before being acquired by Google, Tempow focused on pushing the limits of Bluetooth technology and successfully collaborated with CEVA to deliver synchronized left/right audio over standard Bluetooth dual mode connected links with short latency and without the power consumption penalty associated with many of today’s TWS implementations. Again, ahead of the curve of the Bluetooth SIG efforts and meeting real market requirements. Even when LE Audio was announced, in 2020, Tempow released a new Bluetooth Software Stack for LE Audio development and launched a partnership program for chipset manufacturers to use Tempow’s implementation since it offered two things that manufacturers were looking to have.

In January of that year, Vincent Nallatamby, the CEO and founder of Tempow wrote an article for The Audio Voice, in which he revisited his journey and explained why his company decided to pivot from Bluetooth speakers to True Wireless Earbuds (TWE). In this article, "The True Potential of True Wireless Earbuds" he stated: "This new generation of the protocol will significantly improve the performance of Bluetooth Audio and enable a new generation of Wireless Earbuds capable of substantial optimization from both a technical and user experience perspective. Seizing this opportunity are a new generation of chipset manufacturers embracing Bluetooth Audio, bringing a much welcomed diversity in the landscape with novel approaches and innovations.”

As Mark Powell, CEO of the Bluetooth SIG now confirms in the Auracast broadcast audio announcement, the new solution makes this same vision a reality - even though the creation of a "technology" and separate trademark seems to imply that its scope falls beyond the original LE Audio specifications.

"The launch of Auracast broadcast audio will trigger another massive change in the wireless audio market. The ability to broadcast and share audio using Bluetooth technology will reshape personal audio and enable public venues and spaces to deliver audio experiences that will improve visitor satisfaction and increase accessibility,” Mark Powell says.

Most curiously, the Auracast press release included a statement from none-other than Google about the technology potential. Peter Liu, System Architect, Pixel Ecosystem Products at Google says: "We are proud to work with the Bluetooth SIG and are excited to see this capability provide consumers with new, imaginative ways to connect with each other and hear their world." So, did Google acquire Tempow and "offer" the solution to be part of the Bluetooth specification - hence explaining the requirement for a separate branding? Most likely.

One way or another, the specifications that define Auracast broadcast audio will now be part of the Bluetooth LE Audio specification suite and are expected to be released within "the next few months." We will need to wait for product development solutions to understand what is required and included. The Auracast implementation has two different levels of sophistication. The original Audio Sharing feature depends mostly on the smartphone, earbuds/headphones and speaker manufacturers to enable it in existing chipsets, and it’s mostly software, as Tempow demonstrated. The Broadcast Audio implementation will require more hardware solutions (and antennas) to meet all the different application scenarios - and there are multiple.

Auracast broadcast audio will now be promoted for the ability to "Share Our Audio," allowing users to invite others to share their audio experience - at the personal level, and "Unmute Our World," for pure broadcast audio applications. Examples long envisioned and already available over Wi-Fi will now be implemented over Bluetooth, such as the ability to enjoy television sound in public spaces. Silent televisions in public venues such as airports, gymnasiums, restaurants, and waiting rooms will be able to broadcast audio that any visitor with Auracast-enabled Bluetooth earbuds or hearing aids will be able to hear.

Another logical avenue of the technology is the "Hear Our Best" application, where Auracast broadcast audio will support hearing assist when visiting a public venue such as a transit center, cinema, conference center, or house of worship. Visitors to those spaces will be able to receive audio broadcasts from the public address system directly into their Auracast enabled Bluetooth earbuds or hearing device. Travelers at an airport, for instance, will be able to receive essential flight announcements such as gate changes, boarding schedules, and other travel information directly to their personal audio device. When used in this manner, Auracast broadcast audio will function as "the next-generation assistive listening system (ALS) technology," the Bluetooth SIG states.

As Nick Hunn, CTO of WiFore states: "Auracast broadcast audio is well positioned to become an advanced, new assistive listening system that will be significantly easier and lower in cost to deploy while offering higher audio quality and greater privacy, improving audio accessibility and promoting better living through better hearing."

There will be many challenges to this strategy. There's a lot to be said about these Auracast application scenarios and how relevant they will be to encourage the technology's adoption. I am not certain at all about how popular most of those "TV sound on the sports bar" or "multi-language airport announcements" use cases will be, and I can foresee many technical hurdles to overcome, which are unrelated to Bluetooth. And while hearing assistance remains one of the most noble use cases for Auracast broadcast audio, I also believe that it can be better achieved using Wi-Fi instead of Bluetooth (or both, most often). In fact, experience in that domain tells us that the challenge is always in the implementation of the source signals - and that remains true for hearing loops. The fact that TWS earbuds can receive the Bluetooth streams directly and not Wi-Fi is not really the point, since access to any of those features will likely need to be done from an external device (smartphone, watch) connected over Wi-Fi. Earbuds are and remain an intermediary device for such applications, compared with old hearing aids with telecoils.

For reference we just have to look at the actual experiences from Listen Technologies or Sennheiser with its MobileConnect solution. Both companies have extensive experience and they had the technical solution fully implemented. Smartphones all have Wi-Fi, an app that allows for low latency and an ideal user interface, and radio coverage over Wi-Fi is superior. Neither of the two companies has achieved significant success with their solutions (if we ask Listen Technologies, they probably consider their business very successful - maybe just not for the metrics used by Samsung or Google). Before selling that part of their business to EPOS and Sonova, Sennheiser was well-aware that true wireless earbuds would be used in both business and education applications, as well as assistive listening for users with hearing disabilities - and they were happy to sell that business.

My other main concern is that the Bluetooth SIG is still not in tune with the market trends and requirements for audio applications. The Bluetooth SIG continues to believe that applications other than audio are the future for Bluetooth technology. The organization (or someone within it) is not prioritizing its most important applications, and is not looking at the market requirements for more bandwidth, lower latency, and a more robust and seamless user experience with multi-device connectivity - which is possible but remains an afterthought and is not reliable. These are all critical points that the Bluetooth specifications need to address - required by the whole audio and gaming industries, which together account for the vast majority of Bluetooth devices shipping today.

Ignoring those pressing requirements, and instead expanding the scope of the technology to new applications - such as Auracast does - is just adding a new layer of complexity that might not be necessarily a priority for the industry.

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