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.
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 Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012