LC3 (Low Complexity Communication Codec) is a royalty-free audio codec specified by the Bluetooth Special Interest Group (SIG) for the Bluetooth Low Energy (BLE)'s audio protocol and introduced about the time of Bluetooth 5.2. It is developed by Fraunhofer IIS and Ericsson, and succeeds the SBC codec. Mono (single-channelled) LC3-SWB is supported over the Hands-Free Profile (HFP) 1.9, succeeding mSBC. A Bluetooth LE peripheral can receive up to 4 audio streams (e.g., that of 4 different audio channels) simultaneously. Pairs of wireless earbuds often register as a single peripheral device, despite being physically distinct.

Codec

LC3 provides higher audio quality and better packet loss concealment than SBC and G.722, with disputed results against Opus, according to subjective testing done by the Bluetooth SIG and ETSI. The comparison against Opus is disputed for the test including only speech audio, and using the older 1.1.4 version of the reference Opus encoder, at complexity level 0 at 32 kbps and relying on CELT (general audio) instead of the FEC-capable SILK (speech); the test also did not take into account the newer version 1.2 of the Opus encoder released in 2017, where significant improvements were made to low bitrate streams.

Supported systems:

LC3plus

LC3plus is defined by ETSI and is not royalty free nor compatible with the standard LC3 codec. It's included in the 2019 DECT standard, and is source-available. The codec received Hi-Res certification from the Japan Audio Society (JAS) in 2022, alongside the SCL6, LDAC and LHDC.

See also

  • List of codecs#Bluetooth for a list of audio codecs designed for Bluetooth
  • List of codecs#Audio compression formats for all audio codecs in general