ITU-T P.340

This Recommendation defines the generic transmission characteristics of hands-free terminals, whatever the applications or technologies integrated. In addition to the parameters that ensure performance levels equivalent to these of handset terminals (sensitivity values, response curves, etc.), it defines the parameters which have a bearing on conversation quality (gain switching characteristics, double-talk performances,etc.). It also defines categories of hands-free terminals based on the terminal's double-talk capability. This Recommendation deals with the characteristics of the signal-processing equipment (e. g. acoustic echo cancellation (AEC)) that can be incorporated in hands-free terminals.