Anti-side tone transmitter

摘要

Anti-side tone transmitter insertable in a telephone handset improves transmission of the speaker's voice without distortion in high ambient noise environments. The transmitter cap is provided with a central opening in communication with an electret microphone. One or more satellite openings are spaced from and at least partially surround the central opening. An acoustic damping element is located below the satellite openings. The electret microphone is mounted below the cap on a PC board which contains the transmitter circuitry. The PC board is seated on a shelf formed in the interior surface of the side wall of the transmitter cup. Conventional telephone handset cord transmitter wires may be connected to screw terminals on the base of the transmitter cup or to spade lugs mounted on the PC board.