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College Physics

Glossary

College PhysicsGlossary

Glossary

acoustic impedance
property of medium that makes the propagation of sound waves more difficult
antinode
point of maximum displacement
bow wake
V-shaped disturbance created when the wave source moves faster than the wave propagation speed
Doppler effect
an alteration in the observed frequency of a sound due to motion of either the source or the observer
Doppler shift
the actual change in frequency due to relative motion of source and observer
Doppler-shifted ultrasound
a medical technique to detect motion and determine velocity through the Doppler shift of an echo
fundamental
the lowest-frequency resonance
harmonics
the term used to refer collectively to the fundamental and its overtones
hearing
the perception of sound
infrasound
sounds below 20 Hz
intensity
the power per unit area carried by a wave
intensity reflection coefficient
a measure of the ratio of the intensity of the wave reflected off a boundary between two media relative to the intensity of the incident wave
loudness
the perception of sound intensity
node
point of zero displacement
note
basic unit of music with specific names, combined to generate tunes
overtones
all resonant frequencies higher than the fundamental
phon
the numerical unit of loudness
pitch
the perception of the frequency of a sound
sonic boom
a constructive interference of sound created by an object moving faster than sound
sound
a disturbance of matter that is transmitted from its source outward
sound intensity level
a unitless quantity telling you the level of the sound relative to a fixed standard
sound pressure level
the ratio of the pressure amplitude to a reference pressure
timbre
number and relative intensity of multiple sound frequencies
tone
number and relative intensity of multiple sound frequencies
ultrasound
sounds above 20,000 Hz
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