A processing device according to an embodiment includes: a frequency characteristics acquisition unit configured to acquire frequency characteristics of at least one sound pickup signal; a smoothing processing unit configured to perform smoothing processing so as to generate second spectral data smoother than first spectral data based on the frequency characteristics; a first compression unit configured to calculate a first difference value corresponding to a difference between the second spectral data and the first spectral data in a first band, and to compress the second spectral data based on the first difference value; and a filter generation unit configured to generate a filter, based on the second spectral data.