| A | B |
|---|
| compression | a region of higher density or pressure in a wave |
| rarefaction | a region of lower density or pressure in a wave |
| vibration | the complete back-and-forth motion of an object |
| wave | a disturbance that transmits energy through matter or space |
| medium | a substance through which a wave can travel |
| inner ear | the part of the ear where vibrations created by sound are changed into electrical signals for the brain to interpret |
| middle ear | the part of the ear where the amplitude of sound vibrations is increased |
| outer ear | the part of the ear that acts as a funnel to direct sound waves into the middle ear |
| tinnitus | hearing loss resulting from damage to the hair cells and nerve endings in the cochlea |
| frequency | the number of waves produced in a given amount of time |
| hertz | (Hz) the unit used to express frequency; one hertz is one cycle per second |
| 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 |
| Doppler effect | the apparent change in the frequency of a sound caused by the motion of either the listener or the source of the sound (refers to sound only) |
| loudness | how loud or soft a sound is perceived to be |
| amplitude | the maximum distance a wave vibrates from its rest position |
| decibel | (db) the most common unit used to express loudness |
| oscilloscope | a device used to graph representations of sound waves |
| echo | a reflected sound wave |
| reflection | the bouncing back of a wave after it strikes a barrier or an object |
| echolocation | the process of using reflected sound waves to find objects |
| sonar | (sound navigation ranging) a type of electronic echolocation |
| ultrasonography | a medical procedure that uses echoes from ultrasonic waves to "see" inside a patient's body without performing surgery |
| constructive interference | interference that results in a wave that has a greater amplitude than that of the individual wave |
| destructive interference | interference that results in a wave that has a smaller amplitude than that of the individual wave |
| interference | a 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 ear |
| standing wave | a wave that forms a stationary pattern in which portions of the wave do not move and other portions move with a large amplitude |
| fundamental | the lowest resonant frequency |
| overtones | resonant frequencies that are higher than the fundamental |
| resonance | what occurs when an object vibrating at or near a resonant frequency of a second object causes the second object to vibrate |
| resonant frequencies | the frequencies at which standing waves are made |
| diffraction | the bending of waves around a barrier or through an opening |
| sound quality | the result of several pitches blending together through interference |
| noise | any undesired sound, especially nonmusical sound, that includes a random mix of pitches |
