Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!convex!schumach From: schumach@convex.com (Richard A. Schumacher) Newsgroups: sci.bio Subject: Re: The internal buzz Keywords: bats Message-ID: Date: 13 Feb 91 00:45:28 GMT References: <91041.230852IO80214@MAINE.BITNET> <2580@beguine.UUCP> Sender: news@convex.com (news access account) Organization: Convex Computer Corporation, Richardson, Tx. Lines: 7 Nntp-Posting-Host: magnum.convex.com Some possibilities: 1) damage to auditory nerves caused by exposure to loud sounds or simple aging. 2) A version of a weird and amusing phenomenon reported in Science News sometime in 1989 [I haven't found it yet] in which some guinea pigs ears were found to generate high-pitched tones, occasionally loud enough to be heard several feet away. The mechanism was unknown.