ITU-T Recommendations

Recommendation ITU-T P.341 provides audio performance requirements for wideband audio (8000 Hz) digital loudspeaking and hands-free telephones.

Requirements and test methods are specified for the major audio transmission parameters affecting wideband audio, including sending and receiving levels, frequency response, noise, distortion, stability, echo path and delay. Associated test methods are also given. Wideband audio represents a considerable departure from traditional telephony, offering significantly improved quality.

Main changes over the previous version of this Recommendation (2005) are as follows:
– The structure of the Recommendation is modified; the objective measurement methods originally in Annex A have been transferred into the main body.
– In addition to sinusoidal and noise signals, speech-like stimulus signals, as described in Recommendation ITU-T P.50 and Recommendation ITU-T P.501, are also recommended for the measurements.
– HATS method is introduced for better compliance with practical application.
Some technical requirements and related test methods have been modified according to new development, e.g., frequency response, distortion and delay in sending and receiving direction.