Abstract: A telephone headset apparatus is disclosed. This headset apparatus includes a body having a microphone at one end and a transducer at the opposite end, an earhook, for attaching the apparatus to the ear of the operator, and a mechanism, contained within the body in a movable engagement, for holding the earhook in a frictional engagement that allows for movement of the earhook, with three degrees of freedom. The mechanism is located at a point within the body where upon adjustment of the earhook by the operator (i.e., rotated, tilted, pivoted) the headset apparatus remains properly balanced and within the sound envelope of an operator, for uninterrupted operation.

Abstract: An on-line indicator (40) for the multipurpose headset amplifier comprises a holder in two parts (45) arranged to be snapped onto the ascending, holder (10) which is mounted on the housing (5) of the multipurpose headset amplifier. The on-line indicator has a rotatable indicator or light emitting diode (41) which is coupled to the multipurpose headset amplifier by means of a cable (42). The light diode will light up when the headset is in use to indicate to others that the user of the headset is on the line.

Abstract: An audio frequency compressing system for amplifying an input signal to produce a power output signal while removing high-level signals which could harm a listener. Gain control in the feedback path of an amplifier includes both a gain controller circuit for supplying a constant feedback impedance and a plurality of resistors which can be coupled to the gain controller circuit to increase or decrease the feedback impedance. Coupling of the resistors to the gain controller circuit is controlled by a feedback control circuit having both an automatic gain control circuit and a continuous high-level protection circuit.

Abstract: A multipurpose headset amplifier for the connection of a headset (11) to a telephone instrument comprises a housing (5) having an ascending, thready holder (10) for a headset (11) and connection jacks (21, 22, 23) for the headset (11), the telephone instrument (22) and for the telephone instrument's handset, the housing having at the upper side comprises manuel operating members (6, 7, 8) for the adjustment of the device, and manual controls (15) at the underside for the adaptation of a headset to the impedance and signal level of any telephone instrument. The amplifier comprises an internal power supply (12) and a jack (13) for external power supply. The amplifier is furthermore provided with a microphone switch having a light-emitting diode (9), a volume control (7) and a switch (6).

Abstract: A headset (1) with sound receiving microphone (6) and sound reproducing transducer (3) is arranged to be worn on a person's outer ear (2). For this purpose, the headset has a post auricle mount (9) with a lengthwise adjustable stabilizer (10) behind the ear, said post auricle mount being secured to the sound reproducing transducer housing (3) in a pivotable manner, hereby enabling it to be swivelled in several directions.