Noise-proof telephone set

Abstract

Abstract PURPOSE:To attain the release of both hands and to prevent the reduction in speech quality due to side tone noise, by mounting the ear piece of a handset to an ear. CONSTITUTION:In case of transmission, the sound pressure of voice is produced from an ear T3 into an air-tight chamber C, diaphragms T1, T2 are driven and currents I1, I2 are produced in circuit. A discriminating circuit Bc discriminates transmission or receiving by amplifying the currents I1, I2 and obtaining the ratio of the currents I1, I2 at an electronic circuit Br. The gain of amplifiers K1, K2 is taken negative or positive for the transmission and it is taken inversely positive or negative for the receiving. Thus, a telephone set for one-ear transmission/receiving is realized.

Inventors

• 👤 Giichi Ito
• 👤 義一 伊藤

Bibliographic Details