| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a digital acoustic signal processing apparatus capable of making focal sharpness of an acoustic beam of a directive array speaker high. <P>SOLUTION: In the digital acoustic signal processing apparatus which reproduces a digital acoustic signal input from a sound source by a speaker array constituted of a plurality of speakers whose directivity characteristics are controlled by a two-dimensional digital filter and which are arranged along the linear direction, the two-dimensional digital filter makes the focal sharpness S larger compared with the case where beam transition range width is 20° by narrowing the beam transition range width to 10° so that amplitude at a beam edge angle ϕ<SB>S</SB>becomes ≥0.5 at distance to two to three times of focal distance when the spectrum of the acoustic signal to which two-dimensional Fourier transform is performed for time and positions of the speakers is expressed on a two-dimensional frequency plane consisting of a time frequency axis and a space frequency axis. <P>COPYRIGHT: (C)2011,JPO&INPIT |
