Patent ID: 8160887

Claim:
An audio signal output device for outputting based on a digital audio signal, comprising: a judging unit for judging a frequency of reversals in polarity of a digital audio signal; and a selecting unit for switching an output between an output based on a first interpolated digital audio signal obtained by interpolating the digital audio signal by way of a first interpolation processing and an output based on a second interpolated digital audio signal obtained by interpolating the digital audio signal by way of a second interpolation processing in response to a judgment result made by the judging unit; and wherein the judging unit judges whether or not the frequency of reversals in polarity of the digital audio signal is equal to or larger than a predetermined reference frequency; the first interpolation processing comprises Lagrange interpolation processing or spline interpolation processing; the second interpolation processing comprises zero-order interpolation processing for, after zero signals are inserted in intermediate portions of sampling points of the digital audio signal, performing a low-pass filter processing with respect to the digital audio signal; the selecting unit switches the output to the output based on the second interpolated digital audio signal for cases in which the frequency of reversals in polarity of the digital audio signal is equal to or larger than the predetermined reference frequency; and the predetermined reference frequency is determined based on a sampling frequency of the digital audio signal.