This parameter determination device is provided with: a spectral envelope estimation unit (42) which sets a parameter (Eta 0) and a parameter (Eta) as positive numbers, and uses the parameter (Eta 0) determined by a prescribed method to estimate a spectral envelope by considering the Eta 0 power of the absolute value of a frequency domain sample sequence corresponding to a time-series signal to be a power spectrum; a whitened-spectral-series generation unit (43) for obtaining a whitened spectral series, i.e. a series obtained by dividing the frequency domain sample sequence by the spectral envelope; and a parameter acquisition unit (44) for obtaining the parameter (Eta) with which a generalized Gaussian distribution using the parameter (Eta) as a shape parameter approximates a histogram of the whitened spectral series.