December 1992
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12 Citations
When a single harmonic of a complex sound is mistuned, it influences the pitch of the complex unless it is mistuned by more than about 8% (Moore et al., 1985). We have investigated how the mistuning of a single component influences the pitch of two simultaneous complex tones, with harmonic frequencies close to those of the single mistuned component. Specifically we have asked whether a harmonic that is exactly in tune with one harmonic series (eg 600 Hz to a 200 Hz fundamental) can still contribute to the pitch of another complex tone (eg 145 Hz fundamental) for which it is mistuned. Our experiment employed a pitch-matching task and used 410ms duration sounds. In an earlier experiment using binaural tones (Darwin et al., 1990) a 200 Hz series (first 12 harmonics) was paired with either a 145 or 155 Hz series, with the third harmonic of the 200 Hz series and the fourth harmonic of the other series being replaced by a single tone of variable frequency. Its results showed that a single harmonic could contribute to the pitch of both simultaneous complex tones; it was not ‘captured’ by the series for which it is most in tune. In the experiment reported here the complex tones are presented dichotically with a single mistuned component going to one ear. Subjects matched the pitches on the two ears in different sessions. The results showed that the mistuned component can still influence the pitch of the complex in the opposite ear, even when it is in tune with the series on its own ear, although it makes less of contribution than when it is on the same ear. The experiment also presents a single harmonic series to one ear, and a single mistuned component on either the opposite ear or the same ear. Again the contribution of the contralateral tone is less than that of the ipsilateral tone. Comparison of the single and double conditions shows that there is some tendency for one harmonic complex to capture a tone from another, when it is more in tune with the first.