Ovel Physics principles (chapter 2) Key terms

absorption

process whereby sound energy is dissipated in a medium, primarily in the form of heat

acoustic

having to do with sound

acoustic impedance

resistance of sound as it propagates through a medium

acoustic variables

effects on the sound beam caused by the medium; includes pressure, density, and particle motion (distance and temperature)

amplitude

relating to the strength of the compression wave; maximum variation of an acoustic variable

area

amount of space within a specific boundary

attenuation

weakening of sound as it propagates through a medium

attenuation coefficient

attenuation occurring with each cm that sound travels

bandwidth

range of frequencies found in pulse ultrasound

compression

region of high pressure or density in a compression wave

continuous wave

a nonpulsed wave in which ch cycles repeat indefinitely

cycle

one complete variation in pressure or other acoustic variable

decibel

a unit used to compare the ratio of intensities or amplitudes of two sound waves or two points along the wave

density

concentration of mass, weight, or matter per unit volume

dispertion

dependence of velocity or other physical parameters on frequency

duty factor

fraction of time that pulse ultrasound is on