Patent ID: 8917884

Claim:
A signal processing device comprising: an orthogonal transformer to orthogonally transform two sound signals in a time domain received from first and second sound signal input elements at different positions into two spectral signals in a frequency domain, to generate first and second spectra, respectively; a phase difference determiner to determine a phase difference between the first and second spectra for each frequency; and a virtual spectrum generator to shift a phase of each spectral component of one spectrum of the first and second spectra, in accordance with the phase difference for each frequency, positions of the first and second sound signal input elements, and a virtual position of a virtual sound signal input element, to thereby generate a virtual spectrum for the virtual sound signal input element, and wherein the virtual spectrum is assumed as generated for a virtual sound signal from a virtual sound signal input element located at a virtual position outside a segment of the first and second sound signal input elements on a straight line passing through positions of the first and second sound signal input elements, and wherein when a distance between the first and second sound signal input elements is greater than a value of a velocity of sound divided by a sampling rate for the two sound signals, the virtual spectrum generator generates the virtual spectrum in a range of frequencies which is smaller than a value of the velocity of sound divided by twice the distance.