For those not familiar with Greg's work, this presentation on the testing he did for the Opus codec is informative: https://www.ietf.org/proceedings/82/slides/c

For those not familiar with Greg's work, this presentation on the testing he did for the Opus codec is informative: https://www.ietf.org/proceedings/82/slides/codec-4.pdf https://www.ietf.org/proceedings/82/slides/codec-4.pdf Particularly slide 20.