acoustic generator: A transducer which converts electrical, mechanical, or other forms of energy into sound.
acoustic heat engine: A device that transforms heat energy first into sound energy and then into electrical power, without the use of moving mechanical parts.
acoustic hologram: The phase interference pattern, formed by acoustic beams, that is used in acoustical holography, when light is made to interact with this pattern, it forms an image of an object placed in one of the beams.
acoustic horn: NULL
acoustic jamming: The deliberate radiation or reradiation of mechanical or electroacoustic signals with the objectives of obliterating or obscuring signals which the enemy is attempting to receive and of deterring enemy weapons systems.
acoustic labyrinth: Special baffle arrangement used with a loudspeaker to prevent cavity resonance and to reinforce bass response.
acoustic line: The acoustic equivalent of an electrical transmission line, involving baffles, labyrinths, or resonators placed at the rear of a loudspeaker and arranged to help reproduce the very low audio frequencies.
acoustic ocean-current meter: An instrument that measures current flow in rivers and oceans by transmitting acoustic pulses in opposite directions parallel to the flow and measuring the difference in pulse travel times between transmitter-receiver pairs.
acoustic position reference system: An acoustic system used in offshore oil drilling to provide continuous information on ship position with respect to an ocean-floor acoustic beacon transmitting an ultrasonic signal to three hydrophones on the bottom of the drilling ship.
acoustic radar: Use of sound waves with radar techniques for remote probing of the lower atmosphere, up to heights of about 5000 feet (1500 meters), for measuring wind speed and direction, humidity, temperature inversions, and turbulence.
acoustic radiator: A vibrating surface that produces sound waves, such as a loudspeaker cone or a headphone diaphragm.
acoustic radiometer: An instrument for measuring sound intensity by determining the unidirectional steady-state pressure caused by the reflection or absorption of a sound wave at a boundary.
acoustic ratio: The ratio of the intensity of sound radiated directly from a source to the intensity of sound reverberating from the walls of an enclosure, at a given point in the enclosure.
acoustic reflex enclosure: A loudspeaker cabinet designed with a port to allow a low-frequency contribution from the rear of the speaker cone to be radiated forward.
acoustic regeneration: NULL