Nearly all people who have tried psilocybes report a temporary but
dramatic change in overall perception, particularly visually but
sometimes with their sense of hearing. It is common especially for
people to report hearing a greater sense of depth and texture in music
particularly but also in people's voices. Certain sounds may even
inspire a visual corresponding to that sound, perhaps similarly to a
rare condition known as "Synesthesia."
Here is a dictionary defintion of "Synesthesia":
A condition in which one type of stimulation evokes the sensation of another,
as when the hearing of a sound produces the visualization of a color.
Mushrooms can temporarily make certain
individuals more sensitive to stimuli than they would otherwise be. As
a result, it is possible that they are able to hear "better" with a
longer range of hearing. There has not been much research done in this
Author Terrence McKennna?
wrote that early man's use of psilocybin mushrooms induced better
visual movement detection and hence gave an edge in hunting for food.
From a perspective on physics, the human ear
cannot generally hear above 20,000Hz or below 20Hz. This is the
physical limitation the human auditory system can achieve. Some can
push these boundries with significant study to cognitivly perceive
higher or lower ranges, but that is an art of both hearing and feeling
vibrations in an environment. Psychoacoustics research tells us that if
anything we are designed to hear the center third of the afore
mentioned frequency range. Therefore some auditory effects may be a
result of acutely tuning into that range of sound frequency. A similar
effect can be heard by listening to two rips of an mp3, one at 128kb
and the other at 320kb. You'll note that if played on a good sound
system, that even the untrained ear will easily hear the difference.
Just a few ramblings from a visiting audiovisual engineer.