Re: Implicit human echolocation

[Thomas G Brennan <g_brennantg@xxxxxxxxxxxxxxx>]

Peter, I've done a few studies with blind folks that I've never published as its
difficultish for an individual to publish alonw.  I have found glasses to be
problematic in the real mobility world.  One problem with lab studies is that
you don't have real world inputs and the signals become so undifferentiated that
they can be hard to hear, especially in the case of "passive" echo location
which is really not passive at all or we wouldn't be able to hear it.  I have
some frequency spread data that I've published in an o&m book that shows
approximately where some frequency splits are for differing kinds of echo
location tasks.  Both the frequencies that I believe are used as well as how you
process the sounds differ for different tasks and in different environments.
What really made me a believer in cultural echo location (I like that term) is
spending some time in Mexico working with some blind children there.  Even snow
creates such a different environment that echo location skills must nearly be
thrown out the window and relearned for snow specific environments and even then
you almost have to use active location and it doesn't do much good.

Tom


Tom Brennan  KD5VIJ, CCC-A/SLP
web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html