Vehicle-mounted three dimensional sound field reproducing unit

Abstract

In correspondence with the left and right external ears of a listener occupying a seat, a three dimensional sound field reproducing unit includes at least more than two speakers disposed on a headrest on the top of a backrest of the seat, and three dimensional signal processing means which converts an output signal from a sound source into a three dimensional sound field signal for supplying it to each of the speakers. Three dimensional sound field with high accuracy and fidelity is reproduced near the external ears of the listener.

1 . A three dimensional sound field reproducing unit including at least two speakers for generating sound fields near external ears in correspondence with left and right external ears of a listener occupying a seat; and a three dimensional signal processing means for converting an output signal from a sound source into a three dimensional sound field signal; said unit comprising:
 a seated position memory which stores therein an seated position of the listener;   a seated position control part for reading out the seated position from said seated position memory interlocked with an adjustment of the seated position; and   a convolution coefficient control part for reading out a convolution coefficient based on the seated position supplied from said seated position control part for supplying it to said three dimensional signal processing means.   
   
   
       2 . A three dimensional sound field reproducing unit including at least two speakers for generating sound fields near external ears in correspondence with left and right external ears of a listener occupying a seat; and three dimensional signal processing means for converting an output signal from a sound source into a three dimensional sound field signal for supplying it to each of said speakers; said unit comprising:
 a convolution coefficient memory which stores therein, as an previously measured inverse transfer coefficient, an inverse transfer function;   a transfer characteristic measuring part for reading out a convolution coefficient from said convolution coefficient memory depending on the measured transfer characteristic; and   a convolution coefficient control part for supplying the convolution coefficient supplied from said transfer characteristic measuring part to said three dimensional signal processing part.