The Recommendation specifies the acoustical and electrical characteristics of the Artificial Mouth used for telephonometric measurements.
The sound radiation patterns are specified at a number of points in front of the mouth, as well as the sound diffraction characteristics occurring by inserting a reference obstacle in the sound field generated by the mouth. Also the dynamic range of the generated sound is specified, as well as the linearity characteristics of the device.
The proposed revision of this Recommendation affects the latter aspects, namely the distortion and output linearity requirements of the Artificial Mouth.