When a bat cries, it mutes the middle ear by muscle action and applies
inhibitory reafference on the spiral ganglion cells to reduce their
spiking. I suspect bird audition is similar.
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Harry Erwin, Internet: herwin at gmu.edu, Web Page: http://osf1.gmu.edu/~herwin
PhD student in computational neurosci and lecturer for CS 211 (advanced C++)