SPEECH RECOGNITION SYSTEM AND GAIN SETTING SYSTEM

摘要

When an instruction to start voice input is received from the user, a gain controller acquires, from a gain table which defines a correspondence between vehicle speed ranges and gains, a gain corresponding to a vehicle speed range including the vehicle speed of a vehicle detected by a vehicle speed detector, and sets the acquired gain as the gain of an input amplifier that amplifies an input audio signal output by a microphone. As a gain corresponding to each vehicle speed range, the gain table records a gain of the input amplifier corresponding, in an experimentally determined frequency distribution of peak values in the vehicle speed range, to a maximum frequency in the range of magnitude of voice output as an input audio signal by the microphone and to be input to a speech recognition engine as voice having a magnitude within the input range of the speech recognition engine.

主权项

1. A speech recognition system mounted on a vehicle, comprising:
a microphone configured to convert input voice into an input audio signal and output the input audio signal; a variable-gain input amplifier configured to amplify the input audio signal output by the microphone; a speech recognition unit configured to perform speech recognition on voice represented by the input audio signal amplified by the input amplifier; a vehicle speed detector configured to detect a vehicle speed of the vehicle; a storage unit configured to store gain control information which records a correspondence between vehicle speeds of the vehicle and gains of the input amplifier; and a gain controller configured to acquire the vehicle speed detected by the vehicle speed detector, and to control a gain of the input amplifier to a gain recorded in the gain control information as a gain corresponding to the acquired vehicle speed.