While this is likely common knowledge in this community, Mumble uses the Opus codec, which is a significant factor[1] in Mumble audio being both high quality and very low latency.
Prior to Opus, Mumble used CELT.[2] This was a precursor to the Opus codec developed by Xiph.org, makers of the very well known Ogg container format and Vorbis audio codec.
Prior to Opus, Mumble used CELT.[2] This was a precursor to the Opus codec developed by Xiph.org, makers of the very well known Ogg container format and Vorbis audio codec.
[1] https://www.opus-codec.org/comparison/
[2] https://en.wikipedia.org/wiki/CELT