Effects of the pattern of spectral spacing on the perceptual fusion of harmonics

Harmonic relations are important in the perceptual fusion of frequency components, but other factors can influence how much any given harmonic is integrated into a complex tone. This study considers whether the pattern of spectral spacing can act as such a factor. A complex tone consisting only of odd‐numbered harmonics has a regular harmonic spacing of twice the fundamental frequency. The addition of a single even‐numbered harmonic will locally disrupt this regular pattern. If harmonic relations alone limit the perceptual integration of the added harmonic, it should be as well integrated into the complex as its odd‐numbered neighbors. Subjects were required to ‘‘hear out’’ one of the components of the complex and either to rate its perceived clarity (experiment 1) or to judge its pitch in relation to a pure tone 6% higher or lower in frequency (experiment 2). For a fundamental of 100 or 200 Hz, but not 400 Hz, the even harmonic generally could be heard out more easily than its odd neighbors. It is propos...