Subject: Pinna and chimpanzee questions From: Kevin Austin <kevin.austin@xxxxxxxx> Date: Sat, 15 Nov 2008 02:51:42 -0500 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Regarding azimuth estimation, somewhere I read another term for the ridge in the pinna called the antihelix -- the "Darwinian ridge", although I can find no such reference with Google. Is this structure more complex in humans than in chimpanzees (for example)? http://158.130.17.5/~myl/languagelog/archives/chimp.jpg The abstract http://www.news.cornell.edu/releases/Dec03/chimp.life.hrs.html notes that chimpanzees also do not have the same frequency response as humans: Mutations in alpha tectorin result in poor frequency response of the ear, making it hard to understand speech. ... The large divergence between humans and chimps in alpha tectorin, he says, could imply that humans needed to tune the protein for specific attributes of their sense of hearing. This leads Clark to wonder whether one of the difficulties in training chimpanzees to understand human speech is that their hearing is not quite up to the task. Although studies of chimpanzee hearing have been done, detailed tests of their transient response have not been carried out. What is the effect of plastic surgery on azimuth response? http://www.plasticsurgery4u.com/procedure_folder/revision_otoplasty/revise_overfoldedantihelix.htm Best Kevin
