Central processes in the perception of pitch in simultaneous complex tones

Abstract

Pitch identification of two simultaneous complex tones is more difficult than pitch identification of a single complex tone. In this talk, the more central processes that are involved in the perception of simultaneous complex tones will be discussed. Experiments are reported in which subjects had to identify two missing fundamental frequencies. A first set of experiments uses simultaneous two‐tone complexes with different distributions of the four partial over the ears. It is shown that subjects can identify the two missing fundamental frequencies and that the identification results only weakly depend on the manner of distributing the four partials over the ears. For some subjects, the identification results showed that the more salient pitch can inhibit to some extent the identification of the less salient one. This “central interference” is most prominent when the partials of the two complex tones are widely separated. In a second set of experiments, the influence of signal duration on the virtual pitch of single and simultaneous complex tones is investigated. The results for single complex tones allow the formulation of a stochastic pitch model in which a central processor derives noisy subharmonics from noisy representation of the partials. For simultaneous complex tones, the behavior is more difficult to model because of the more central processes that are involved.