Abstract: A modular microphone assembly housed in a handsfree telephone apparatus provides an environment that is isolated from a loudspeaker installed within the apparatus and through which environment the directional and frequency response characteristics of a directional microphone capsule contained within a closable cavity of a microphone mounting receptacle in the assembly are altered via a predetermined internal surface configuration of the receptacle to improve the performance of the apparatus.

Abstract: A telephone handset having a receiver housing at one end has a flux coil positioned at the front corner at the junction between the peripheral wall and the front wall of the housing. The flux coil is connected in series or in parallel with the receiver. The flux coil, by this arrangement, is positioned very close to the front face of the receiver housing, giving very good coupling between flux coil and a hearing aid. Normally unused space is occupied by the flux coil and permits use of any convenient receiver.

Abstract: A directional microphone assembly in which an electroacoustic transducer housed in a capsule, having a directional response characteristic, is mounted in the assembly housing and surrounded by an acoustically transparent foam covering. As a result acoustic waves reflected off surfaces of the housing are dispersed so as to minimize the effect of the surfaces on the directional response characteristic.

Abstract: The invention provides an enclosure arrangement or a loudspeaker adapted to be mounted in a voice communication terminal. The invention provides primary and secondary enclosures for the loudspeaker. The primary enclosure comprises a piece of resilient open cell foam material having one face provided with a concavity suitable for receiving the spider and the voice coil structure of the loudspeaker. The peripheral edge of the one face of the foam material is secured to the peripheral edge of the spider and the outer surface of the foam material has a flexible layer of substantially air-impermeable material, whereby the loudspeaker is provided with an attached flexible enclosure. The secondary enclosure comprises the housing in which the loudspeaker is mounted. The flexibility of the primary enclosure allows energy to be coupled between itself and the secondary enclosure.