On the New Scientist question. The yawning effect on pitch may be related to the
pitch shift observed on clenching the jaw, reported by Corey JASA 22, 640 (1950).
It seems possible that these pitch shifts are the result of intensity changes and the
pitch-intensity effect, but they don't sound that way. An alternative explanation would
be that pressure on the oval (or round) window biases the basilar membrane a little
so that the place of maximum excitation shifts slightly. Then the place theory of
pitch perception would predict a pitch shift.
Another way to get pitch shifts is to bias the basilar membrane with a very low-
frequency tone (as in a masking period pattern experiment) and observe the pitch
of a high-frequency tone presented in the peaks or the valleys of the low-frequency
Hope to see you all at ASA Fort Lauderdale in a few weeks!