SPEECH RECOGNITION SYSTEM FOR AN AUTOMOTIVE VEHICLE

摘要

A speech recognition system for an automotive vehicle which can record or recognize spoken instruction phrases reliably even when engine noise increases high within the passenger compartment. When the engine begins to operate, the gain of an amplifier of a speech input section or the threshold level of a voice detector is so switched as to reduce the sensitivity to spoken instructions. As a result, the driver must necessarily utter a spoken instruction in a louder voice and thus the proportion of noise level to spoken instruction signal level is reduced. The system according to the present invention comprises engine operation detecting means, an analog switch, two amplifiers or two multipliers, etc. in addition to the conventional speech recognizer.