As described above, in the present embodiment, the processing device 201 makes the normalization factor computation unit 216 compute a normalization factor, based on scale converted data. This processing enables the normalization unit 217 to perform normalization, using an appropriate normalization factor. It is possible to compute a normalization factor, focusing on an important band in terms of the auditory sense. In general, when a signal in the time domain is normalized, a normalization factor is determined in such a way that a square sum or an RMS (root-mean-square) has a preset value. The processing of the present embodiment enables a more appropriate normalization factor to be determined than in the case where such a general method is used.

Measurement of ear canal transfer characteristics of the person 1 being measured is performed using the microphone unit 2 and the headphones 43. Further, the processing device 201 can be configured using a smartphone or the like. Therefore, there is a possibility that settings of the measurement differ for each measurement. There is also a possibility that variation occurs in wearing status of the headphones 43 and the microphone unit 2. The processing device 201 performs normalization by multiplying an ECTF by the normalization factor Std computed as described above. Performing processing as described above enables ear canal transfer characteristics to be measured with variance due to settings and the like at the time of measurement suppressed.