5. Bitrate efficiency: We calculate bitrate efficiency as the sum of the entropy (in bits) of each
codebook when applied on a large test set divided by the number of bits across all codebooks.
For efficient bitrate utilization this should tend to 100% and lower percentages indicate that
the bitrate is being underutilized.

We also conduct a MUSHRA-inspired listening test, with a hidden reference, but no low-passed
anchor. In it each one of ten expert listeners rated 12 randomly selected 10-second samples from
our evaluation set, 4 of each domain; speech, music and environmental sounds. We compare our
proposed system at 2.67kbps, 5.33kbps and 8kbps to EnCodec at 3kbps, 6kbps and 12kbps.

4.5 Ablation study
RVQGAN