Patent ID: 8331590

Claim:
A delay time calculation apparatus for a speaker array having N number of speaker units, where N is an integer greater than two, the apparatus comprising: a setting unit configured to set N number of respective sound receiving points corresponding to the N number of speaker units within a target area, the sound receiving points and the target area respectively being target arrival points and a target emission region for acoustic waves output from the speaker units of the speaker array; and a control unit programmed to calculate delay times for each of the speaker units, between the control unit receiving an input audio signal and supplying the input audio signal to each of the speaker units, wherein the control unit is programmed to: determine (a) a first average value of distance differences between: (1) distances R(j,j) from each of non-target speaker units that are not currently targeted for calculation of the delay time, to the respective sound receiving point thereof, and (2) distances R(i,j) from one current target speaker unit for which the delay time is to be calculated to each of the sound receiving points corresponding to the non-target speaker units, based on an expression Σ[R(j,j)−R(i,j)]/(N−1); and determine (b) a second average value of distance differences between: (3) distances R(j,i) from each of the non-target speaker units to the one sound receiving point corresponding to the target speaker unit, and (4) distance R(i,i) from the target speaker unit to the respective sound receiving point, based on an expression Σ[R(j,i)−R(i,i)]/(N−1), wherein i and j each represent an integer from 1 to N, and for each of i from 1 to N, j is incremented from 1 to N, but so that j≠i, to calculate for each of the first and second average value of distance differences for each of the target speaker units; determine for each of the target speaker units an average value of the first average value and the second average value; and convert the average of the first and second average values for each of the target speaker units into the delay time therefor.