Reduced parasitic coupling mobile telephone having loudspeaker processing circuits with high/low impedance electrical/mechanical drive coils switch activated for personal/hands free listening.

摘要

The mobile telephone (1) has speech and loudspeaker processing circuits (3). The loudspeaker is held on a structure (13). There is a switch (19) with two outputs (22,23) connected to a processing circuit (10) providing two outputs, the first driving a coil converting electrical to mechanical outputs (18) and the second providing a second electrical to mechanical drive. The first coil is high impedance for personal listening whilst the second is low impedance for hands free use.