Acoustic Transducer

acoustic transducer

[ə′küs·tik tranz′dü·sər]
(engineering acoustics)
A device that converts acoustic energy to electrical or mechanical energy, such as a microphone or phonograph pickup.

Transducer, Acoustic

 

an acoustic device for the perception and conversion of sound signals for purposes of measurement, transmission, playback, recording, or analysis.

Transducers that convert acoustic signals into electrical signals (electroacoustic transducers) are the most common. They include microphones, which are used in air; hydrophones, which are used under water; and Geophones, which are used underground. The most important characteristics of such transducers are sensitivity, which is the ratio between the electrical signal (voltage, current) and the acoustic signal (for example, sound pressure); frequency response; electrical self-impedance; and directivity pattern.

In addition to transducers that produce an electrical signal that reproduces the time variations of the corresponding acoustic signal (pressure, fluctuative particle velocity), transducers also exist that measure the averaged characteristics of a sound wave. They include, for example, the Rayleigh disk and radiometers. Thermocouples encapsulated in a sound-absorptive envelope are used in the ultrasonic range; their electromotive force is proportional to the ultrasound intensity.

The auditory organs of animals and humans may be treated as sound detectors that convert acoustic signals into nerve impulses that are transmitted to the brain centers.

I. G. RUSAKOV

References in periodicals archive ?
Electromagnetic acoustic transducer for ultrasonic thickness gauging of ferromagnetic metal items without removing dielectric coating.
Electromagnetic acoustic transducer (EMAT) is a kind of sensor which can excite and receive ultrasonic waves without coupling agent.
Figure 1 shows a specific acoustic transducer layout in a square measuring area (10 m x 10 m) isometrically divided into 100 blocks by dashed lines.
According to the company, RAM noninvasively and continuously measures respiration rate using an innovative adhesive sensor with an integrated acoustic transducer, the RAS-125c and now RAS-45, that is applied to the patient's neck.
Mathematical model of electromagnetic acoustic transducer, using COMSOL multiphysics has been perfomed.
(NYSE: OII), a global oilfield provider of engineered services and products, has acquired Spectrum Sales & Services LLC, a non-destructive examination company that has developed subsea pipeline inspection technology based on the use of Electro Magnetic Acoustic Transducer technology.
Each photoacoustic emission from the speckle grains is weighted by the Gaussian detection sensitivity of the acoustic transducer [104].
The approach to inspecting these pipelines is through the use of tethered, robotic, crawler-type tools that use the non-contact electro-magnetic acoustic transducer (EMAT) method of ultrasonic inspection.
In 2009, mobile Electro-Magnetic Acoustic Transducer (EMAT) technology was used for valve pit inspections, and transverse MFL technology inspections were added for specific pipelines.
The amplitude of the internal electrical pulse that generates impulses for the electro acoustic transducer is much higher than the expected amplitude of the echo-signal response.
Masimo Rainbow Acoustic Monitoring non-invasively and continuously measures respiration rate using an innovative adhesive sensor with an integrated acoustic transducer that is applied to the patient's neck to detect upper airway acoustic vibrations on the surface of the skin during the respiratory cycle.