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.