Telephonometry: The Practical Acoustics of Handsets, Headsets, and Mobile Devices

Acoustics & Psychoacoustics

Presenter:
Christopher Struck, CJS Labs - San Francisco, CA, USA; Acoustical Society of America

This tutorial introduces the basic concepts of Telephonometry with respect to electroacoustic measurements on analogue and digital telephones. Objective methods are emphasized, however, the relationship to subjective measures is also discussed. The historical concept of Loudness Rating and standardized methods for its calculation are reviewed. Standard objective measurements of send, receive, and sidetone are explained. The selection and use of appropriate instrumentation, including ear and mouth simulators, is also described. Techniques for the evaluation of handsets, headsets, speakerphones, and other hands-free devices are presented. Applications of these measurements to analogue, digital, cellular, and VOIP devices are explained. Issues with extended bandwidth devices are discussed and various methods specified in the ITU-T, IEEE, TIA, ETSI, and 3GPP standards are explained.