Sound is the transmission of mechanical waves in matter. It can only be transmitted through matter and cannot be transmitted in a vacuum. The human ear is sensitive to certain frequencies of sound waves, typically in the range of 20–20,000 cycles/second or hertz (Hz). The ear detects mechanical vibrations in the air and the nervous system transmits them to the brain. Sound is comprised of longitudinal mechanical waves travelling through matter. Sound waves are generated by the successive compression and rarefaction of the media that is transmitting it. Sound waves represent a successive increase and decrease in pressure in the media transmitting them. The frequency of sound is normally referred to as its pitch. Pitch describes the audible effect that a frequency of sound waves has on the human ear. Pitch is normally measured in hertz (Hz) or cycles/second.
By Gary Conner
By George N Bullen FSME