Subject: Re: Pitch perception shift caused by carbamazepine and yawning From: Martin Braun <nombraun(at)TELIA.COM> Date: Tue, 30 Nov 2004 20:59:50 +0100Chen-Gia Tsai asked: > I find that a recent experimental study on yawning might shed new light on the pitch perception shift during yawning. > (....................) > As yawning is under the control of several neurotransmitters and neuropeptides at the central level, is it possible that yawning-induced pitch shift can be explained in terms of neurochemistry? Changes in neurochemistry might change the propensity of yawning. Auditory changes DURING yawning, however, need not have neural origins. During yawning the Eustachian tube can open, which often changes air pressure in the middle ear and thus hearing. Yawning can also trigger the middle ear muscles. Both effects can change loudness, but not pitch. Also changes in afferent or efferent auditory signaling during yawning would affect loudness, but not pitch. So, if there are reliable reports of pitch shift during yawning, I would be interested to see them. Martin ---------------------------- Martin Braun Neuroscience of Music S-671 95 Klassbol Sweden web site: http://w1.570.telia.com/~u57011259/index.htm