Rarefaction

Technology / Home Audio / Rarefaction: In sound waves, the opposite of compression. An area of decreased air pressure caused by a sound wave. In a graphical depiction of a cyclical waveform rarefaction occurs when the wave is in the bottom segment. Sound is simply the alternating compression and rarefaction of air at varying and often overlapping frequencies, within a range to which humans are sensitive.
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Thunder

Science / Weather / Thunder: The sound emitted by rapidly expanding gases along the channel of a lightning discharge. Over three-quarters of lightning's electrical discharge is used in heating the gases in the atmosphere in and i MORE

Acoustics

Technology / Home Audio / Acoustics: Sound is simply vibrating air. How fast, how much, and when the air is vibrated, determines what we will ultimately hear as sound. The science of this process is called acoustics. When a speaker cone MORE

Sound Waves

Technology / Home Audio / Sound Waves: Fluctuating waves of barometric pressure that travel through a physical medium such as air. An acoustic wave consists of a traveling vibration of alternate compressions and rarefactions, whereby sound MORE