Subject: Re: ITDs From: Harry Erwin <harry.erwin@xxxxxxxx> Date: Wed, 23 Sep 2009 08:48:27 +0100 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Sound shadowing is much more effective at high frequencies, so the pinnae and head can evolve to take advantage of the interaural intensity difference cue. However, at low frequencies, sound shadowing is much less marked and animals are forced to use something else. Animals that use low frequency sounds a lot tend to be bigger, so there are usually significant onset time and phase difference cues that can be exploited. Onset time doesn't provide much information, particularly for continuous sounds, but phase difference is vulnerable to multipath signals and echoes. You pays your money and takes your choice. The MiCRAM robot our lab is developing uses all of the above, and we are investigating other approaches, including triangulation, target motion analysis, and more complex cues. On 23 Sep 2009, at 04:23, David Schwartz wrote: > Greetings. > > I'm struggling to understand why the interaural time difference is > an effective localization cue for low frequency sound but not for > high frequency sound. Can anyone help to clear up my confusion? > > Thanks. > > David -- Harry Erwin, PhD, Senior Lecturer of Computing, University of Sunderland. Computational neuroethologist: http://crowan-scat.sunderland.ac.uk/~harryerw/mediawiki/index.php