Bluetooth LE Audio Archives - Creative Connectivity

The story of Auracast broadcast audio

If you’ve not heard of Auracast, it won’t be long until you do. It’s a new audio feature for Bluetooth products which lets lots of people listen to the same audio stream. The concept came from the hearing aid industry, which wanted to find a way of expanding the experience that people had with Telecoil hearing loops into the wider ecosystem, bringing the ability to share audio from phones and TVs. They felt that if this could be done with Bluetooth, it would also make it far easier to install hearing assistance in public venues, such as theatres, community halls and churches, as well as providing travel information to your earbuds or headphone at airports, bus shelters and train stations. Today, thousands of venues around the world have already installed Auracast transmitters. It’s supported by the latest Samsung and Pixel phones, and is integrated in new Samsung, LG and Panasonic TVs. The latest hearing aids can listen to these Auracast signals, and a growing range of consumer earbuds and headphones can also receive them. Although it started as a feature to help people with hearing loss, over the course of its development it’s been enthusiastically supported by the wider audio industry, bringing a new experience to everyone.

Has the audio industry lost its imagination?

If you read the glossy audio magazines (audio enthusiasts still buy them), or spend some time browsing Amazon, you’ll see an audio industry which appears to be in good health. Depending on your personal preferences you can get something that’s smaller, shinier, lossless, retro, or virtually any adjective you can think of. But if you strip off the marketing glitz, it’s questionable whether audio quality has improved much in the last seventy years.

For the first 25 years, families huddled around horns. Then, in 1925, loudspeakers appeared, bringing sound to everyone in a room. The industry spent the next quarter century improving quality, to the point where most music lovers thought that audio reproduction was about as good as it was going to get. 1950s and 60s novels were populated with characters enthusing about their preamplifiers and graphic equalisers as they listened to the finer points of Mozart and Beethoven.

Then the focus changed. Other priorities took over, as multiple disruptions changed the way we listen to music. What’s interesting is that each of these disruptions was accompanied by a reduction in audio quality, as consumers decided that other features were more important. It’s not a message that the audio industry likes to acknowledge, as trying to push “higher” quality often seems to be the limit of their imagination. But history suggests they may be about to have another shock. So, let’s look at the reality of what happened. It all started in 1957 with:

Bluetooth and Auracast are changing the way microphones are designed

Most people have a view about their speakers, earbuds and headphones. They’ll happily enthuse about the audio performance, how well the noise cancellation works, their battery life and features like transparency. But nobody talks about microphones. The most you’re ever likely to hear is an exasperated “can you hear me” during a phone conversation, or a possibly muted oath about whether they’re muted and how to turn the mute on or off.

Auracast and the Evolution of the Earbud Case

Sometimes, it needs what seems to be a small, tangential innovation to make a product successful. At the time, it may not seem much, but it can result in the product acquiring a life of its own. One product which is making its way along that trajectory is the humble earbud charging case.

The history of the charging case is quite interesting. Stereo wireless earbuds were a long time coming. It needed some serious technical innovation by a couple of chip companies to make them possible – new technology by Cambridge Silicon Radio (now part of Qualcomm) to let them receive and render separate left and right audio channels, and small near-field magnetic induction chips from another silicon company – NXP to send wireless signals through our heads. It then needed the brilliance of a German startup called Bragi to turn these concepts into working stereo earbuds, kickstarting the whole hearables market. It has become the fastest growing technology product ever, eclipsing even the iPhone in its growth.

Introducing Bluetooth LE Audio – the book

Just before Christmas, the Bluetooth SIG published the final documents in the first release of Bluetooth LE Audio. It’s been the largest single development in the history of the Bluetooth specifications, taking around eight years and comprising 25 new or updated documents, with over 1,250 pages of specification. Its aim is ambitious, the intent being to provide the platform for the next twenty years of wireless audio development.

Sock Puppets, Codecs and Bluetooth LE Audio

One of the perks of working in technology standards groups is that you get to go to meetings in nice places around the world. A more minor perk is that the standards group tends to provide gifts for the participants. They’re not generally much more than a T-shirt saying you’ve been there, or a packet of the local equivalent of popcorn or haggis, but they’re something to remember it by.

Last year, Covid put an end to international travel and we’ve been having to make do with virtual conferences. As every standards group is discovering, they’re OK, but they don’t really work as well. It’s far more difficult to have a good argument when you’re not face to face and there’s no substitute for a fight for the whiteboard markers or the reconciliations and wild flights of fancy that take place over a beer or a coffee. For most standards, the even greater casualty is in testing, where prototype implementations normally come together to check that the specifications actually work. Few companies are happy to let their prototypes out of their sight and running tests remotely, especially for wireless standards, is incredibly difficult. Every standards group is suffering from that at the moment, with the result that we’re seeing release dates pushed back and features cut down.