Subject: Re: Testing whether some humans can hear high frequencies inaudible to "normal" humans From: Tom Brennan <g_brennantg@xxxxxxxx> Date: Sun, 13 Jun 2010 20:19:44 -0500 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Obviously the first thing you're going to want to do is to have a good standard audiometric battery done. Some kids with "autism spectrum" as well as some other disorders develop hyperacusis hence are not really responding to high frequency sounds. Pretty muchy any audiometer can test up to 8k and several can test up to 12k. There are a few which can test up to 20k but problems with transducers at frequencies that high limit how useful such testing really is. Equipment for calibration is pretty much lacking up in that area. When I was younger my hearing was tssted up to 26k but in order to do this we used high frequency equipment normally used for animals. If you want to really test high frequency hearing up there you'll almost surely need specialized lab equipment. A computer isn't going to be able to produce those high frequencies because of transducer problems. Also, on a computer you would be completely lacking calibration. The computer rout is probably not viable except as a control unit for other equipment. Tom Tom Brennan KD5VIJ, CCC-A/SLP web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html