Bluetooth SIG, the industry group in charge of defining the standard, has released a new audio codec that promises to make wireless headphones more power-efficient while improving sound quality. The Low Complexity Communication Codec, or LC3 for short, can transmit at much lower bitrates without as big a drop in audio quality as you see with Bluetooth’s standard, and much maligned, SBC codec. The development of the new codec was first announced back at CES 2020.
Offering listenable audio at lower bitrates means headphones can use less power. That’s particularly important for true wireless earbuds, which have to strike a difficult balance between size, weight, battery life, and audio quality. LC3 allows audio to be transmitted at half the bitrate of SBC without suffering a big drop in audio quality, the Bluetooth SIG says. This increase in efficiency means earbuds can be less bulky thanks to using smaller batteries, or can offer better battery life at the same size.
You can listen to a comparison between SBC and LC3 above (or find it on the Bluetooth site here). Notice how SBC starts to sound crackly even at 192 kbps, while LC3 still sounds clear at 128 kbps. To my ears, LC3 starts to sound pretty rough at 96 kbps, but it’s a trade-off I’d be willing to accept for an ultra-small pair of workout earbuds.
LC3 is just one of the new technologies coming as part of Bluetooth LE Audio, an umbrella term for a collection of new Bluetooth features that includes support for hearing aids and the ability to broadcast to an “unlimited” number of audio devices.
Also included in LE Audio is the ability to stream to two audio devices simultaneously thanks to support for multistream audio, which is helpful if you want to send an independent audio stream to each individual bud in a true wireless pair. By default, Bluetooth sends data to one earbud, which then sends the audio to the other side. Apple and Qualcomm already support similar functionality with their own proprietary Bluetooth software, but now it’s becoming part of the Bluetooth SIG’s spec.
The Bluetooth SIG says companies are already developing products using the new LC3 codec, and a Q&A posted on the site says these products should be available next year.