Patent ID: 8249259

Claim:
A voice intelligibility enhancement system that is mounted in a vehicle and controls a gain of a voice signal based on noise power and a voice power of a voice signal generated by a voice signal generation unit, the voice intelligibility enhancement system comprising: a voice power detection unit configured to detect whether the voice power is equal to or greater than a predetermined level; a noise power measurement unit configured to measure noise power; a noise power storage unit configured to store noise power output when the voice power is less than the predetermined level; and a gain control unit configured to control the gain of a voice signal and configured to estimate noise power to be output when the voice power exceeds the predetermined level to be the stored noise power; a transmission characteristics identification unit that, in identification mode available when a vehicle is stopped, identifies characteristics of transmission from a speaker that outputs voice to a microphone that detects noise; and a transmission characteristics application unit that, in normal operation mode, applies the characteristics of transmission to the voice power to output voice power at a position of the microphone, wherein the gain control unit controls gain of a voice signal based on the voice power output from the transmission characteristics application unit and the estimated noise power.