How do loudly calling birds not deafen themselves?

[Andrew Taylor <>]

On Fri, Feb 08, 2008 at 08:27:52AM +1100, Tania Ireton wrote:
> A friend rang me last night to ask how loudly calling birds such as Rainbow
> Lorikeets and Sulphur-crested Cockatoos not deafen themselves with their
> screeching?  She was reading a new book on cicadas which said that cicadas
> are able to disconnect something in their hearing so as to deaden the
> incoming sound before they started calling themselves (I didn?t get all the
> details).  She wanted to know how birds manage.  Any ideas?

An involuntary contraction of muscles in your ear reduces their
sensitivity when you shout and something similar happens in other mammals
and birds.  Bird inner ears are also more resistant to damage from loud
noises than mammals and regenerate if damaged.  Some (all?) cicadas
fold their tympanums when singing.  A very different response has been
seen crickets where the auditory neurons are inhibited during sound
productrion and this may occur in other groups.

"Nature's Music: The Science of Birdsong" by Marler & Slabbekoorn is
a great ref for this sort of science.

Andrew