Chapter 20 & 21 Vocabulary Words
reflection
The bouncing back of a wave after it strikes a barrier or an object
echo
A reflected sound wave
echolocation
The process of using reflected sound waves to find objects
interference
Wave interaction that occurs when two or more waves overlap
sonic boom
The explosive sound heard when a shock wave from an object traveling faster than the
speed of sound reaches a person’s ears
pitch
How high or low a sound is perceived to be
infrasonic
The term describing sounds with frequencies lower than 20 Hz
ultrasonic
The term describing sounds with frequencies higher than 20,000 Hz
The apparent change in the frequency of a sound caused by the motion of either the
listener or the source of the sound
A wave in which the particles of the wave’s medium vibrate perpendicularly to the
transverse wave
direction the wave is traveling
A wave in which the particles in the medium vibrate back and forth along the path of that
longitudinal wave
the wave travels
Doppler Effect
amplitude
standing wave
resonance
The maximum distance a wave vibrates from its rest point
A wave that forms a stationary pattern in which portions of the wave do not move and
other portions move with large amplitudes
What occurs when an object vibrating at or near a resonant frequency of a second object
causes the second object to vibrate
diffraction
The bending of waves around a barrier or through an opening
refraction
The bending of a wave as it passes at an angle from one medium to another
decibel
The most common unit used to express loudness
wave
A disturbance that transmits energy through matter or space
medium
A substance through which a wave can travel
wave speed
Speed at which a wave travels
frequency
The number of waves produced in a given amount of time
wavelength
The distance between one point on a wave and the corresponding point on an adjacent
wave in a series of waves
loudness
How loud or soft a sound is perceived to be
Hertz
Unit for frequency
Constructive
interference
Destructive
interference
Occurs when the crests of one wave overlap the crests of another wave or waves
Occurs when the crests of one wave overlap the troughs of another wave