Acoustic Lens definition of Acoustic Lens in the Free Online Encyclopedia.

acoustic lens [ə′küs·tik ′lenz]

(materials)

Selected materials shaped to refract sound waves in accordance with the principles of geometrical optics, as is done for light. Also known as lens.

Lens, Acoustic

a device used to modify the convergence of (that is, to focus) sound beams.

Like optical lenses, acoustic lenses are bounded by two working surfaces. Acoustic lenses are made of a material for which the speed of sound differs from that in the surrounding medium, so that the refractive index n is a number other than unity. In order to attain maximum transmittance, the wave drag of the material should approximate that of the ambient and the viscous losses should be minimal.

Acoustic lenses may be solid, liquid, or gas. In a liquid or gas lens, the lens’s solid casing should exhibit maximum transmittance. For work in liquid media, the material for the lens may be plastic (n = 0.5–0.8), chloroform, or carbon tetrachloride (n = 1.3–1.4). Lenses filled with hydrogen or carbon dioxide are used along with nonhomogenous acoustic lenses filled with pellets or mesh for work in gases (for example, air). Nonhomogeneous diverging air lenses are used to improve the directivity characteristics of loudspeakers. Solid and liquid lenses are used for acoustic images, flaw detection, medical diagnosis, and the concentration of ultrasound for a variety of technological and biological purposes.

REFERENCES

Bergmann, L. Ul’trazvuk i ego primenenie v nauke i technike, 2nd ed. Moscow, 1957. (Translated from German.)

Mentioned in	?		References in periodicals archive	?		Encyclopedia browser	?		Full browser	?
No references found	Already proving popular in the Audi Q7 UK order book, the bespoke Bang & Olufsen Advanced Sound System boasts 14 speakers, unique acoustic lens tweeters and Bang & Olufsen's patented ICEpower digital amplifier technology. Sound is Bang on by Daily Record (Glasgow, Scotland) I wish I had stumbled across Moulton's earlier, mid-1980s writings where he had claimed: A novel acoustic lens has been devised which allows the acoustic radiation field of two or more transducers to be coupled in phase such Nat the resultant acoustic radiation pattern is interference-free at all frequencies, and displays wide and nearly frequency independent beam width. Bang & Olufsen BeoLab 5 by Moran, David / Sensible Sound These include underwater cameras, hull scanning, commercial sonars, acoustic guidance, and acoustic lens sonar. Security technologies should be networked, Pentagon says by Tiron, Roxana / National Defense	acoustic dispersion acoustic domain acoustic emission acoustic energy acoustic fatigue acoustic feedback Acoustic Filter acoustic fingerprint acoustic fix acoustic generator acoustic grating acoustic heat engine acoustic hologram acoustic homing acoustic horn acoustic image acoustic imaging Acoustic Impedance acoustic inertance acoustic insulation Acoustic Intensifier acoustic intensity acoustic interferometer acoustic jamming acoustic labyrinth Acoustic Lens acoustic levitation acoustic line acoustic line of position acoustic logging acoustic Mach meter acoustic mass acoustic mass reactance Acoustic Materials acoustic measurement Acoustic Measurements acoustic memory acoustic microscope acoustic mine acoustic mode acoustic navigation acoustic nerve acoustic noise acoustic ocean-current meter acoustic ohm acoustic particle detection acoustic phonon acoustic plaster acoustic position reference system Acoustic Power Acoustic Probe	Acoustic Imaging Acoustic Imaging System acoustic impedance acoustic impedance acoustic impedance acoustic impedances acoustic impedances acoustic impedances Acoustic Induced Vibration acoustic inertance Acoustic Input Processing System Acoustic insulation Acoustic insulation acoustic intelligence acoustic intelligence Acoustic Intelligence Data System Acoustic Intelligence Gathering System Acoustic Intelligence Processing System Acoustic Intensifier Acoustic intensity Acoustic Intercept Receiver Acoustic Intercept Receiver Detect/Track Acoustic Intercept System Acoustic Interference Monitor System Acoustic interferometer acoustic jamming acoustic jamming Acoustic Kung Fu Films acoustic labyrinth Acoustic Leak Detection Acoustic Lens Acoustic Lens Simulation Software Package Acoustic levitation acoustic line acoustic line of position Acoustic Link Control Software Acoustic Literature Map of Europe Acoustic Local Area Network acoustic logging acoustic Mach meter acoustic maculae acoustic maculae acoustic maculae acoustic maculae acoustic mass acoustic mass reactance Acoustic Materials acoustic measurement Acoustic Measurement Facilities Improvement Program Acoustic Measurement System Acoustic Measurements acoustic meatus acoustic meatus acoustic meatus acoustic meatus, meatus acusticus, meatus auditorius, auditory meatus acoustic meatus, meatus acusticus, meatus auditorius, auditory meatus acoustic meatus, meatus acusticus, meatus auditorius, auditory meatus acoustic memory Acoustic Meteorological Observing System acoustic microscope acoustic microscope

Mentioned in

References in periodicals archive

Encyclopedia browser

Full browser

No references found

Already proving popular in the Audi Q7 UK order book, the bespoke Bang & Olufsen Advanced Sound System boasts 14 speakers, unique acoustic lens tweeters and Bang & Olufsen's patented ICEpower digital amplifier technology.

Sound is Bang on by Daily Record (Glasgow, Scotland)

I wish I had stumbled across Moulton's earlier, mid-1980s writings where he had claimed: A novel acoustic lens has been devised which allows the acoustic radiation field of two or more transducers to be coupled in phase such Nat the resultant acoustic radiation pattern is interference-free at all frequencies, and displays wide and nearly frequency independent beam width.

Bang & Olufsen BeoLab 5 by Moran, David / Sensible Sound

These include underwater cameras, hull scanning, commercial sonars, acoustic guidance, and acoustic lens sonar.

Security technologies should be networked, Pentagon says by Tiron, Roxana / National Defense