Sound generation in appts. telephone receivers - has loudspeaker chamber coupled to resonator formed by length of tubing to correct low frequency characteristic

摘要

The noise dampening arrangement has a loudspeaker (5) mounted within a chamber (3) formed by a main housing (7). The housing consists of an upper cap (4) and a lower cap (6) and has sound transmitting apertures (8). The acoustic characteristic of the chamber is adjusted to compensate for the low frequency effects. The compensation is provided by including a resonator chamber (2) that connects with the main housing. This can be in the form of a flexible (or rigid) tube (2) that locates on a formed projection (12). In order to achieve a resonator frequency of 300-400 Hz, the tube is 15-20 cm long. USE/ADVANTAGE - Corrects for LF effects. Acoustic resonator is dimensioned to compensate for undesired acoustic effects. Reverse region of chamber is shielded from noise from reverse region.