/ Dictionary / Index A acoustic impedance: Meaning and Definition of Find definitions for: acous'tic imped'ance Pronunciation: [key] — Acoustics. Acoustics. the total reaction of a medium to the transmission of sound through it, expressed as the ratio of sound pressure to particle velocity at a given point in the medium. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. acoustician acoustic inertance Related Content Daily Word Quiz: languid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language