In its latest update to the Android version of the app, Netflix announced that it is bringing “studio quality” sound to all TV and movies on the app. This is done through Netflix’s decision to switch to xHE-AAC (short for Extended High Efficiency AAC). This codec is a newer version of the HE-AAC Netflix has been using for a while and offers a high compression ratio with bit rates ranging from 12kbps for stereo (6kbps for mono) and all the way to 500kbps.
With its wide bit rate range, xHE-AAC can adapt depending on connection strength and bandwidth. There’s also a mandatory loudness and dynamic range control at the codec level that helps it adapt the sound quality depending on the listening setup.
With this new codec, xHE-AAC is more efficient than its predecessor in terms of data consumption by as much as three times. Compared to MP3 codecs, xHE-AAC gives you over 8 times the listening time per 500mb of data.
In Netflix’s A/B testing, they found out that people prefer the new codec, citing that the improvements in audio quality let them opt to watch using their device’s loudspeaker more than using earphones.
The new codec is expected to roll out on iOS, macOS, and Windows versions of the app soon.