1. Pertaining to the sense of hearing: Dogs are known to have a much greater acoustic range for hearing than humans.
2. A reference to something that can be used to aid a person's hearing: The doctor prescribed an acoustic hearing aid for Mark so he could listen to others better. © ALL rights are reserved.

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A process in which sound energy is reduced as sonic waves strike or pass through a surface: The engineer worked to develop a plan for better acoustic absorption in the large auditorium.

The inability to write from dictation or from what is heard: Dr. Davis is a specialist in treating acoustic agraphias with which several of his patients are afflicted.

Impairment in the understanding of auditory language and communication, including the inability to write from dictation in the presence of normal hearing: Acoustic aphasia consists of sounds that are heard but which convey no meaning, however spontaneous speech, reading, and writing are supposedly not affected.

The numerous body organs and structures consisting of hearing, especially the various parts of the ear: As future ear, eye, nose and throat specialists, some of the medical students found the acoustic apparatus to be the most difficult to master.

The central hearing area in the brain which is located in the temporal lobe of the cerebrum or head: The neurosurgeon was able to successfully perform an operation in the acoustic center of Patricia's brain.

A machine that converts heat into sound energy and then into electrical energy without the use of mechanical parts: Martin was devising an acoustic heat engine which he believed would bring much less expensive electricity to many people in his city.

A guidance system, such as a torpedo, which points directly to a sound signal: The sailors monitored the equipment for acoustic homing, listening for the sound of a ship's propeller.

A partial loss of hearing or a reduced sensitivity to sounds: Mr. Smith, the lawyer, found that the acoustic hypoesthesia which Shirley experienced created difficulty in the courtroom when she needed to hear everything that was said.

The use of sound energy to form a representation of a physical object: Ultrasound tomography on internal human organs is an example of acoustic imaging which includes microscopic pictures that have been produced with sounds.

In ultrasonography, a lens used to focus or to diverge a sound beam which may be simulated by the electronic manipulations of signals: Acoustic lenses are made of a material by which the speed of sound differs from that in the surrounding medium and the acoustic lenses may be solid, liquid, or gas.

The opening to the external or to the internal auditory canal: Dr. Green diagnosed Mike's unexplained loss of hearing as an accumulation of ear wax in his acoustic meatus.

A device in which the object being studied is scanned with sound waves and its image is reconstructed with light waves: In the field of medical surgery, the development of the acoustic microscope was praised as a break through innovation for noninvasive exploratory surgery.

A nerve which consists of two separate parts of the eighth pair of cranial nerves connecting the inner ear with the brain and transmitting impulses concerned with hearing and balance: The acoustic nerve controls the special senses of hearing and equilibrium or balance.

A rare, benign tumor that comes from supporting cells which surround the eighth cranial or auditory nerve: Acoustic neuroma usually exists within the internal auditory meatus which is the canal in the skull though which the nerve emerges into the inner ear.

The symptoms of acoustic neuroma can cause deafness, tinnitus (noises in the ears), loss of balance, and pain in the affected ears.

A diagnostic technique for the detection of middle ear effusion: Acoustic reflectometry measures the level of sound that is transmitted and reflected from the middle ear to a microphone that is located in a probe tip placed against the ear canal opening and diverted towards the tympanic membrane or eardrum.

The distribution of sound waves in several directions caused by multiple reflections and bending diffractions: Usually acoustic scattering occurs with music that is performed in poorly designed auditoriums.

A space into which sounds do not enter because of the refraction of sound waves: Some acoustic shadows take place immediately behind a large object that obstructs the audible waves.

Damaged hearing when a user of a listening device suffers from a sudden loud noise: Monroe's hearing was seriously harmed by an acoustic shock while he was listening to music because at first it was too low, and when he turned the sound up, it jumped up much higher than he had intended for it to be.

A device using sound waves to study the transmissions and reflections that are characteristic of ocean thermal layers and marine organisms: The oceanographers used acoustic spectrographs to determine the various levels of the heat waves of the water and of the creatures that existed in different parts of the sea.

The damage caused to the cochlear structures (parts of the inner ears known as the organs of hearing) by high-intensity sound stimulations (loud noises) that have demonstrable negative effects on hearing: Acoustic trauma is sometimes temporary in the initial stages, but it can result in permanent damage with the continued exposure to loud noises.

To avoid having acoustic trauma, people should wear protective ear plugs or ear-cover protectors to minimize damage to their ears when using loud equipment.

Everyone should be aware of risks of acoustic traumas that are connected with such activities as shooting guns, using chain saws, lawn mowers, driving motorcycles, or when using snowmobiles.

Another way of avoiding acoustic trauma is to refrain from listening to loud music for long periods of time.

Acoustic trauma can occur as a result of an individual's occupation, such as rock musicians, construction workers, airline ground crew members, or by using earphones and headphones, etc. with the volume turned up too much.

The electronic generation and processing of audio signals or the electronic processing of natural sounds, and the manipulation and arrangement of these signals via tape recorders into a finished musical composition: "Electro-acoustic music is recorded and edited on tape and the reproduction involves the use of loudspeakers."

Some electroacoustic music is created by arranging electronically synthesized sounds into a formal pattern with musical qualities which might resemble those of normal musical instruments.

A technique for producing images showing the thermal (heat) and elastic variations in the properties of an object: The process of electron acoustic microscopy consists of an electron beam that generates ultrasonic waves in a specimen which are detected by a piezoelectric transducer whose output controls the brightness of a spot sweeping a cathode-ray tube in synchronism with the electron beam.

A longitudinal compression wave in the ion density of a plasma: An ion-acoustic wave can take place at high electron temperatures and low frequencies, and is effected by a combination of ion inertia and electron pressure.

A technology used for automatic identification in which low power microwave radio frequency signals are converted to ultrasonic acoustic signals by a piezoelectric crystalline material in the transponder: Surface acoustic waves were first described by Lord Rayleigh in 1885.

Variations in the reflected signal can be used to provide a unique identity.

SAW appliances are applied in television and radio.