David A. Collings PE
Sound Quality and
PsychoAcoustics:
The human perception of sound can involve
many factors that reach far beyond the physical science of acoustics. The interpretation
that we place upon the complex audio inputs to our brains can trigger emotions
that range from euphoria to rage. We can be soothed by a babbling brook,
inspired by a symphony concert or driven frantic by a dripping faucet.
Some of the qualitative aspects of sound are
well understood. The harmonizing of tones whose frequencies combine with
numerical compatibility is basic to every type of music, although the human
taste in the rhythmic elements of music can reflect wide cultural and social differences.
Sounds can trigger widely different responses depending upon their context and
we have learned to interpret and classify sounds in many subtle ways. As with
art, the human brain can make associative sub-conscious leaps that can color
our responses to sound patterns in unexpected and sometimes irrational ways.
Our acoustic environment generally has both
foreground and background components. Foreground noises are those that demand
some kind of attention. Speech, warning signals, music, etc. all trigger a
response at some level in our conscious brain. These sounds are superimposed on
an inevitable background of random noise that, to a large extent, is filtered
from the sounds that we hear. When we classify background sounds as noise
pollution, this is often an indication of the quality of the sounds
rather than their measurable levels. Varying, intermittent or impulsive sounds
can be more intrusive than a steady continuous noise that we can easily ignore.
This factor makes the writing and enforcement of noise ordinances much more
difficult. Noise control projects are more likely to be initiated in response
to complaints than by the need to comply with state or national
standards.
Try these links : -