| 摘要 |
A speech recognition system for an automotive vehicle can effectively eliminate noise generated by vehicle engines, and comprises a group of bandpass filters (8) the pass bands of which are approximately from 500 to 600, from 900 to 1200, and from 900 to 2200 Hz, for effectively passing only the speech sound formant frequencies while eliminating the major frequency components of engine noise less than 500 Hz, in addition to the conventional speech recognizer. Further, it is desirable to provide the speech recognition system with a high-frequency compensator (20 B) for enhancing the voltage level of the high frequency components of the electrical signal representing spoken instructions at a rate of 20 dB or more per decimal order of magnitude of increase in frequency and/or a plurality of notch filters for sharply reducing the major engine noise frequency components at 200, 400, and 800 Hz. |
