- 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