ITU-T Recommendations

Recommendation ITU-T P.342 provides audio performance requirements for digital hands-free and loudspeaking telephony terminals using, in the telephone band (300-3400 Hz), the waveform encoding according to Recommendations ITU-T G.711 (PCM at both 64 kbit/s and 56 kbit/s) and ITU-T G.726 (ADPCM 32 kbit/s).This Recommendation does not deal with audio performance requirements for digital telephones using coding schemes other than waveform encoding and at bit rates lower than 32 kbit/s.