Recommendation ITU-T P.58 specifies the electroacoustic characteristics of the head and torso simulator (HATS) to be used for telephonometric measurements. Both the sound generation and sound pick up characteristics of this device are specified. The artificial ears described in this Recommendation support narrowband, wideband, super-wideband, as well as full-band applications. The artificial mouth described in this Recommendation supports narrowband, wideband and super-wideband applications. However, it should be noted that the directionality of the artificial mouth is limited in its ability to simulate the human mouth in the super-wideband frequency range.