Previously, the TWELP 400 bps vocoder showed results comparable to the MELPe 600 bps vocoder, sometimes slightly surpassing or slightly lagging behind it depending on the language. According to the latest evaluations by DSP Innovations, TWELP 400 bps now demonstrates a small but measurable advantage in speech quality and intelligibility compared to MELPe 600 bps — especially in acoustic noise conditions — while operating at a lower bitrate

TWELP 400 bps vocoder

The TWELP 300 bps vocoder has been updated, delivering a noticeable improvement in speech quality and intelligibility. The new version significantly narrows the performance gap with the MELPe 600 bps vocoder, despite operating at only half the bitrate:

TWELP 300 bps vocoder

We tested the CODEC2, MELPe  and TWELP vocoders at 1200 bps bitrate:

CODEC2 vs MELPe vs TWELP at 1200 bps

The new TWELP 400 bps vocoder enables voice communication in extremely challenging conditions where it was previously impossible. It delivers speech quality and intelligibility comparable to or better than MELPe at 600 bps, even while operating at an exceptionally low bit rate

The new version of the TWELP MR (Multi-Rate) vocoder is presented on the following webpage:

TWELP MR vocoder

The new version of the TWELP 2400 bps vocoder is presented on the following webpage:

TWELP 2400 bps vocoder

The new version of the TWELP 1600 bps vocoder is presented on the following webpage:

TWELP 1600 bps vocoder

The new version of the TWELP 1200 bps vocoder is presented on the following webpage:

TWELP 1200 bps vocoder

We tested the CODEC2 and TWELP vocoders, added speech intelligibility scores, and updated the webpages with the results:

CODEC2 vs TWELP at 2400 bps
CODEC2 vs TWELP at 700 bps