Abstract: This invention relates to a telephone handset transformable into a telephone headset. The assembly includes a main unit (10) fitted with a first receiver and a microphone and a unit (12) movable in relation to the main unit that can incorporate a second receiver. The movable unit (12) is connected to the main unit (10) by a connecting component (14) made up of at least two arms (26, 28) adjustable in length and at least partially retractable. They are connected by at least one articulation boss. The microphone is retractable or is integrated into the main unit and then articulated in relation to the connecting component. When the telephone unit passes to an open position, it is transformed into a telephone headset without interruption of reception or transmission.