Sound is produced by ____ objects. Sound waves consist of vibrating particles of ____ and other substances. Sound waves are ____ waves: the vibrations of the particles are ____ to the direction of energy transfer. Like all longitudinal waves, sound waves contain areas of compression and ____. A compression is an area where the particles are ____ together than usual, and there is a ____ pressure. A rarefaction is an area where the particles are further apart than usual, and there is a ____ pressure. Since sound waves consist of ____ vibrating, we say that they require matter, or a ____, to travel. A ____ is a space where there are no particles. Sound waves ____ travel through a vacuum since there are no particles to vibrate and carry the wave. Humans can hear sounds in the range of 20Hz to ____ (20,000Hz). Frequencies above 20kHz are called ____. Frequencies ____ 20Hz are called infrasound. Age and damage reduce the ____ limit, so people who are older or are exposed to prolonged high volumes may not be able to hear above ____.

Sound waves

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