THE LOUDNESS OF “COMPLEX NOISE” IN RELATION TO THE FACTORS EXTRACTED FROM THE AUTO-CORRELATION FUNCTION

The loudness of complex signals, which include bandpass noises with different center frequencies (complex noise), is examined while changing the effective duration of the autocorrelation function (τe) based on a model of the human auditory–brain system for subjective response to a sound field. The center frequencies of each component of the complex noises were 2000 and 3000 Hz so that the perceived pitch was centered on 1000 Hz. The bandwidth of each component was changed by using a 2068 dB/octave sharp filter to control theτe of the source signal. The scale values for the loudness of the complex noises were obtained using a paired-comparison method. The results showed that the loudness increases with the τeof the source signal similar to that of the single-noise component centered on 1000 Hz. The loudness of complex noises having equal sound pressure levels is not constant within the critical band, 160 Hz.