Hello everyone, in this video you can see the differences between various VoIP codecs. I also put the frequency analysis of each codec, so you can see the differences clearly.
Here are the codecs in the video : G.711 alaw, G.711 ulaw, G.722, G.723, G.729, G.729a, G.729ab, G.729b, AMR 8KHz, AMR-WB 16KHz, GSM 8KHz, iLBC 8 KHz, iSAC, OPUS 48KHz, OPUS 24KHz, OPUS 16KHz, OPUS 8KHz.