Explained: What is LC3 codec and how it will help improve the audio and call quality in future Bluetooth headphones and earbuds

The next generation of Apple AirPods are expected to come with new and improved audio quality along with the support for the new LE Audio and LC3 Bluetooth codec support. The latest beta firmware for AirPods are claimed to include support for LC3 codec along with the recently announced iOS16 operating system. The new codec is said to improve the power efficiency along with the audio quality of the upcoming AirPods.
What is LC3 Codec and how it can play an important role in improving the audio and call quality in future Bluetooth headphones?
But, before diving into the entire LC3 codec and its importance, it is important to understand the Low Energy (LE) Audio that was announced by Bluetooth SIG at CES 2020.
There are two types of Bluetooth — the Classic and the LE. The LE stands for Low Energy which further expands to low power, low bandwidth, TWS operations with individual streams and supports low latency. But, it is currently limited to IoT devices like smartwatches and fitness bands. The thing to note is that to date the audio transmission happens via the Bluetooth Classic which includes Bluetooth 1.0, 2.0 and 3.0 irrespective of the codec support which includes SBC, aptX or Sony’s LDAC. However, the LE Audio now allows for audio transmission via low power and bandwidth.
Now, let’s move to the LC3 codec.
What is LC3 codec?
LC3 ((Low Complexity Communication) codec is a Bluetooth audio codec, specially designed for use in LE (Low Energy) Audio profiles. The codec, as per the official Bluetooth SIG website, is capable of encoding speech and music at various bitrates and it can be incorporated into any Bluetooth audio profile. Dot note that the LE Audio and LC3 codec will work with Bluetooth 5.2 which means, users will need a device with that specific or newer Bluetooth version to take advantage of the new Bluetooth codec.
According to Bluetooth’s official website, the LC3 codec compresses the audio to a very low bit rate without sacrificing the audio quality. This allows for not only faster data transmission, but also limited bandwidth.
According to the data provided by SoundGuys, the LC3 scales from 345kbps audio to 160kbps, while the SBC range is limited to 345kbps to 240kbps. Qualcomm’s aptX ranges between 279kbps and 420kbps. Compared to the older codecs, the LC3 is the most compact Bluetooth Codec to date.
Given all these figures, the next question that comes to mind is how the LC3 codec is going to affect the audio quality? Let us explain:
Effect of LE Audio and LC3 codec on audio quality
To explain how the new LC3 codec affects the audio quality, Bluetooth SIG has published a graph comparing the SBC and LC3 audio codecs. As per the graph, the company claims that the LC3 codec is capable of delivering higher quality audio despite being at a lower bit rate. In fact, the graph clearly shows that the LC3 can deliver better audio quality at the same rate as SBC.
This new codec comes with several advantages, it consumes less energy and can transmit bigger packages at a low bit rate which means it requires less bandwidth. It also supports an unlimited number of audio channels along with 8 kHz, 16 kHz, 24 kHz, 32 kHz, 44.1 kHz, and 48 kHz sampling rates and has a wide range of usable bit rates. In addition to that, the LE Audio comes with native support for True wireless earbuds.
Now, it is pretty much clear that the new LE Audio and LC3 codec is highly scalable and is capable of delivering high-quality audio. But, all the other properties of the new Bluetooth technology will give OEMs more flexibility to experiment with their audio devices, they can now make the TWS earbuds much smaller with a smaller battery without sacrificing the battery life or connectivity.
Overall, it will be interesting to see how the entire LE Audio and LC3 codec implementation pans out over time.