Abstract: A vehicle seat backrest incorporates two speakers and an electrically driven extensible/retractable boom carrying a microphone. The boom is supported and guided in grooves in the casing of the extension/retraction assembly. It is constructed of two spring metal straps having arcuate cross section shapes and a flexible insulation layer between the straps. The straps serve as electrical conductors for the microphone and electrical signals are transmitted to and from the straps by brushes. The boom is activated by connection to a toothed belt carried on two toothed pulleys, one of which is driven by an electric motor. The headrest is used with a commercially available cellular telephone having a jack into which the microphone and speakers of the backrest are plugged.