| 摘要 |
PURPOSE:To form a wider acoustic field by supplying reproduced sound obtained by means of removing initial reflected sound from a reproduced signal and that obtained by means of adding initial reflected sound to the reproduced signal to a front speaker based on the correlation function of random noise and a signal from a acoustic/electric conversion means. CONSTITUTION:A digital signal processor 23 generates random noise by setting a mode change over switch 24 to a measurement mode. The processor 23 calculates the mutual correlation function between the original signal of random noise and the signal collected from a microphone 30. When the mode change over switch 24 is set to a reproduction mode, the signal obtained by reducing the level of reflected sound can be obtained by causing an acoustic signal from an acoustic signal source to pass through a digital filter 41. Then, the initial reflected sound whose delay time is comparatively long can be obtained if a delay processing 42 and an attenuation processing 43 are executed on the acoustic signal. The signals are added and they are supplied to instrument panel embedded type speakers 27. |
