(of an explosive mine or other weapon) Able to be set off by sound waves.
Utilizing sound energy in its operation.
(of building materials) Used for soundproofing or modifying sound.
Naturally producing or produced by an instrument without electrical amplification or the need thereof.
The properties or qualities of a room or building that determine how sound is transmitted in it.
A medicine or other agent to assist hearing.
Passing from subsonic to supersonic, or vice versa.
Travelling through a fluid (commonly air) at a speed where regions of supersonic and subsonic flow coexist simultaneously over different portions of the surface of the moving object in question.
Just below, or just above the speed of sound (0.8 < Ma < 1.2 approximately).