Exam 4 Review:  Chapter 15:  Physics of Sound

frequency - The number of times a specified periodic phenomenon occurs within a specified interval, e.g., the number of vibrations per second of a particular tone of sound.

wavelength - The distance between one peak or crest of a wave of light, heat, sound, or other energy and the next corresponding peak or crest in consecutive cycles of a wave; for electromagnetic waves, the wavelength determines the type (radio, infrared, visible, ultraviolet, X-Ray, gamma-ray) of radiation, in the case of visible light, wavelength determines the color of the light.

pitch - The distinctive quality of a sound, dependent primarily on the frequency of the sound waves produced by its source; in music, the relative position of a tone within a range of musical sounds on a scale of high and low, as determined by this quality.

amplitude - The maximum absolute value of a periodically varying quantity; the maximum absolute value of a periodic curve measured along its vertical axis; related to the volume or loudness of a sound.

loudness - The subjective characterization of a sound by its volume and intensity; measured by its amplitude as a wave form.

decibels (dBa) - An exponential scale (powers of 10) to measure sound levels; 0 dB is the threshold of hearing, normal conversation is ~60 dB, a large orchestra is ~100 dB, the threshold of pain is ~130 dB, and instant perforation of the eardrum is 160 dB.

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