Dear List,
Has anyone considered why humans exhibit critical bands in
psycho-acoustical experiments (e.g. masking, loudness summation,
detectability of phase changes)? Is the assumption that the origin
of critical bands is in the physiology of the cochlea? If so, how is
this justified? If critical bands result from overlap/interference
of vibrations on the basilar membrane one would expect their
bandwidths to change significantly at different sound pressure
levels (because more auditory nerve afferents over longer portions
of the cochlea are activated by higher SPLs, and fewer afferents
within restricted areas of the cochlea are activated by lower SPLs),
but this does not seem to be the case.
In vision, attempts to rationalize psychophysical phenomena in terms
of retinal physiology have had very limited success.
Any thoughts would be much appreciated.
Thanks,
Dan