Originally Posted by halo0
Uh oh, here we go.
What do you think sound is, if not the movement of air?
There is a difference between a audible sound, and the air movement caused by the driver moving back and forth.
The number of sound pressure level vibrations (sonic waves) per second denotes the frequency
. Infrasonic (below hearing), sonic (aural), and ultrasonic (above hearing) frequencies are measured in Hertz (Hz); one Hertz is one cycle wave (or singular pressure wave in audionics) per second. Specifically, humans have a maximum aural range that begins as low as 12 Hz under ideal laboratory conditions,
to 20,000 Hz in most children and some adults, but the range shrinks during life, usually beginning at around the age of 8 with the higher frequencies fading. Inaudible sound waves can be detected (felt) by humans through physical body vibration in the range of 4 to 16 Hz. There is a difference in sensitivity of hearing between the sexes, with women typically having a higher sensitivity to higher frequencies than men.http://en.wikipedia.org/wiki/Hearing_range
The human ear can nominally hear sounds in the range 20 Hz
to 20,000 Hz (20 kHz). The upper limit tends to decrease with age; most adults are unable to hear above 16 kHz. The lowest frequency that has been identified as a musical tone is 12 Hz under ideal laboratory conditions.
Tones between 4 and 16 Hz can be perceived via the body's sense of touch