Dynamic Pitch Perception for Complex Tones Derived from Major Triads

A new type of complex tone that demonstrates pitch circularity is described. For such tones, the spectral envelope is trapezoidal on the coordinates of logarithmic frequency and logarithmic amplitude, and remains constant. The components of each tone form a major triad within each octave. The component frequencies were increased by steps of 1/10 octave from tone to tone, until the first tone was obtained again. According to our paired comparison experiments for pitch, which were analyzed using the multidimensional scaling technique, two kinds of pitch circularities appear. One group of subjects shows a pitch circularity corresponding to the exact spectral periodicity of an octave, and the other group a circularity corresponding to the roughly viewed spectral periodicity of 1/3 octave. The human ear seems to detect a global pitch movement when some spectral components move in the same direction by similar degrees on the logarithmic frequency dimension.