Re: finger nails on blackboard

[David Mountain <dcm@xxxxxxxxxxx>]

Several years ago we were working with a type of evoked potential
that we called the envelope following response.  Most of our
work was with sinusoidal carriers and sinusoidal envelopes but
we experimented a bit with pseudo-random envelopes and these
stimuli were among the most unpleasant ones we've ever listened
to.  We ran the stimuli through a simple auditory nerve model
and saw instantaneous firing rates that were much higher than
what one normally sees with continuous stimuli.  It appeared
that brief segements of low amplitude followed by an amplitude
peak was creating a situation where the model nerve fiber could
partially recover from adaptation and thus be able to respond
vigorously to the following peak.

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David C. Mountain, Ph.D.
Professor of Biomedical Engineering
Boston University
44 Cummington St.
Boston, MA 02215

Email:   dcm@bu.edu
Website: http://earlab.bu.edu/dcm/
Phone:   (617) 353-4343
FAX:     (617) 353-6766
Office:  ERB 413