Bluetooth audio is set for a notable shift, and it could help usher in a new generation of headphones.
The ubiquitous wireless standard will move all audio applications onto a new, low-energy radio, called Bluetooth low energy (BLE), by the end of next year, according to Mark Powell, the executive director of the Bluetooth Special Interest Group (SIG).
Bluetooth SIG is the industry body that oversees and promotes the development of Bluetooth as a whole. It counts hundreds of tech companies as members, and has the likes of Microsoft, Intel, and Apple on its board of directors.
Bluetooth low energy is separate from the “classic” Bluetooth BR/EDR protocol most wireless accessories use today. It was adopted into the Bluetooth standard with the Bluetooth 4.0 spec in 2010, and focuses on consuming less power than the traditional tech. As a result, it’s often seen in peripherals like fitness trackers, which only need to send data back to a source device in small batches. Right now, though, it doesn’t have a defined standard for streaming audio.
The SIG has been working to create an official BLE audio streaming standard for “at least 18 months, if not longer,” according to IHS Markit analyst Lee Ratliff, who characterises the shift as an “open secret” within the industry.
The forthcoming Bluetooth 5.0 update, which claims to quadruple the range and double the speed of low-energy connections, could be seen as “foundational release,” according to WiFore CTO Nick Hunn, who is helping develop the tech. The idea is for that to set the stage, mostly benefiting Internet of Things (IoT) devices, then layer the audio functionality on top.
What this change could do
The 5.0 change could bring a few new benefits to wireless headphones and speakers. Since Bluetooth low energy is designed to consume less power, it’d theoretically result in much improved battery life. In a blog post, for instance, Hunn claims BLE audio could enable a smaller headphone like Apple’s AirPods to last for “days, not hours.”
Powell said the range updates coming with Bluetooth 5.0 would apply to audio as well.
He also noted that a user could stream BLE audio to multiple devices at once. This would make it easier to create a multi-room audio system over Bluetooth, Powell said. It would likely sound worse than a WiFi-based system such as a Sonos, but it’d seemingly allow it to be longer-lasting and more portable.
Though Powell said the new standard will apply to all audio devices, the biggest benefactor of the change could be fully wireless earbuds like the aforementioned AirPods.
Two of the most common technical complaints levied toward devices like those are minuscule battery life and choppy connections. Trading the classic, power-hungry Bluetooth audio profile (dubbed A2DP) for BLE would seem to help with the former. Being able to send that stream to two earbuds simultaneously — instead the usual process of sending audio to one earbud, which then recycles it to the other — would seem to make the latter more reliable.
Computers in your ear
The underlying idea here is to further enable smart headphones. Earphones like the AirPods or Bragi Dash hint at the concept today, but the coming years are expected to bring a number of devices that aren’t headphones so much as in-ear computers that also play music.
Many current “smart headphones” can track fitness stats and utilise digital assistants, as the Dash and others do today, but various audio firms are also working on ways to translate foreign languages in real-time, or use selective noise cancelling that could shut off upon hearing certain keywords (like a name).
Features like these would seem to make smart headphones a natural fit for augmented reality devices, which let you see virtual elements on top of the real world. You’d have a computer on your face, and a computer in your ears to go with it. That future is far from reality today, but the audio world is actively working toward it, and major tech firms like Apple have already laid the groundwork for entering the market. Hearables would do a lot of processing, though, so they’d need an efficient connection to stream audio — be it music or a recreation of outside noises — for an extended period of time.
The SIG hopes Bluetooth low energy is what will allow for that. “We’re trying to lay down a release that will support the next 10 years of audio innovation,” Hunn said.
A technical challenge
There are reasons to doubt hearables, though, beyond the obvious question of whether or not people will ever accept it as a concept.
For one, there are privacy concerns. As Motherboard recently noted, a rise in Bluetooth low energy devices means more opportunities to track users via Bluetooth beacons, which can then be accessed by marketers eager to send you location-relevant ads. The SIG itself touts Bluetooth 5.0 as a way to “further propel the adoption and deployment” of said beacons.
Not all beacons are used for surveillance purposes, and it’s possible to opt out of such tracking altogether, but a world where hearables and beacons are prevalent could make it easier for intrusive location tracking to take hold.
Aside from that, there are significant technical challenges to making BLE audio streaming work. For instance, what makes Bluetooth low energy “low energy” is its low duty cycles. It gives devices only a little bit of data at a time, then shuts off to conserve power. Audio, however, streams continuously. Maintaining an efficient connection when there’s no way for that connection to “sleep” is tricky.
This focus on lower bandwidth could make it difficult to improve the quality of the audio itself.
“The challenge would be trying to stream high-quality audio over that link,” said Jeff Hutchings, VP of product at Skullcandy. “You’d probably need a longer duty cycle, which would defeat some of the power savings. But I know they are working on that. And of course, as they continue to do better modulation and demodulation, and better codecs, I think that’s definitely going to become a possibility in the future.”
Indeed, Powell claimed a new slate of codecs and digital signal processors (DSPs) will allow BLE to get around its current audio hangups. Still, he also noted that the classic Bluetooth streaming profile will remain, and predicts many future audio devices — particularly lower-cost ones — will continue to use it. The move just furthers the SIG’s effort to consolidate through BLE.
Apple has a head start
In some ways, the shift to BLE audio could allow other companies to catch up with some of the features Apple has rolled out with its new W1 wireless chip, which allows select Apple and Beats headphones to quickly pair with Apple devices over a special, simplified interface. It also lets them connect with multiple Apple devices simultaneously through iCloud.
While the iCloud-specific features are proprietary to Apple, both Powell and Hunn suspect Apple is using its own Bluetooth low energy core and custom codecs to do the smoother pairing. Powell said the SIG is currently working on techniques that would let the open BLE standard enable a similar sort of fast pairing and connecting, which should come in an update “within the next year or two.”
Apple also claims the W1 chip uses one-third the power of other wireless chips, allowing for better battery life, but right now the gains aren’t terribly dramatic in context. That’s likely because the AirPods and new Beats headphones still stream audio over the classic Bluetooth profile — that’s why they’re able to work with non-Apple devices. Bluetooth 5.0 and up, on the other hand, will require new hardware.
All of this suggests that Apple isn’t breaking away from Bluetooth so much as it’s using the W1 to get a jump start on the SIG’s notoriously slow standards approval process.
“What Apple didn’t have to deal with was all the politics of the SIG and making a standard that, instead of one company being able to use, hundreds of companies can use,” Ratliff said. “They don’t need a super flexible protocol that does everything; they only need one that does audio.”
At the moment, the W1 is proprietary, and Apple is not licensing the tech to third parties. The company did not respond to multiple requests for comment on whether or not this will change going forward.
The switch to BLE audio could create a more level playing field in the near future, but it’s possible that we’re nearing a situation similar to what Apple does with Lightning today, where companies pay Apple a fee to use a solution that’s more polished on its devices.
Both Powell and Hunn said the upcoming Bluetooth update is an extension of work that’s been done with transmitting BLE audio to hearing aids, so it’s worth noting that Apple has already developed a proprietary take on that tech, which the company does licence to others.
Bluetooth always says it will get better next year
In any case, the move shouldn’t be unexpected. The SIG has put more and more focus on Bluetooth low energy with recent updates, the market for hearables has been bubbling for years, and Apple has always leveraged its vertically-integrated position to move faster than standards bodies allow.
Nevertheless, the SIG is hoping its Bluetooth 5.0 update will give the next wave of headphones a platform to build upon in earnest. Whether or not it will finally work out Bluetooth’s infamous kinks, though, is a question for the future.