Personal devices for protection of the ears from loud or high intensity noise, water, or cold. These include earmuffs and earplugs.

Hearing loss due to exposure to explosive loud noise or chronic exposure to sound level greater than 85 dB. The hearing loss is often in the frequency range 4000-6000 hertz.

Noise present in occupational, industrial, and factory situations.

Any sound which is unwanted or interferes with HEARING other sounds.

The comparison of the quantity of meaningful data to the irrelevant or incorrect data.

The audibility limit of discriminating sound intensity and pitch.

A weight-carrying structure for navigation of the air that is supported either by its own buoyancy or by the dynamic action of the air against its surfaces. (Webster, 1973)

The interference of one perceptual stimulus with another causing a decrease or lessening in perceptual effectiveness.

Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis.

Use of sound to elicit a response in the nervous system.

The graphic registration of the frequency and intensity of sounds, such as speech, infant crying, and animal vocalizations.

Processes that incorporate some element of randomness, used particularly to refer to a time series of random variables.

Permanent roads having a line of rails fixed to ties and laid to gage, usually on a leveled or graded ballasted roadbed and providing a track for freight cars, passenger cars, and other rolling stock. Cars are designed to be drawn by locomotives or sometimes propelled by self-contained motors. (From Webster's 3d) The concept includes the organizational and administrative aspects of railroads as well.

The testing of the acuity of the sense of hearing to determine the thresholds of the lowest intensity levels at which an individual can hear a set of tones. The frequencies between 125 and 8000 Hz are used to test air conduction thresholds and the frequencies between 250 and 4000 Hz are used to test bone conduction thresholds.

A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.

The science pertaining to the interrelationship of psychologic phenomena and the individual's response to the physical properties of sound.

The process whereby an utterance is decoded into a representation in terms of linguistic units (sequences of phonetic segments which combine to form lexical and grammatical morphemes).

Measurement of hearing based on the use of pure tones of various frequencies and intensities as auditory stimuli.

The process whereby auditory stimuli are selected, organized, and interpreted by the organism.

Psychophysical technique that permits the estimation of the bias of the observer as well as detectability of the signal (i.e., stimulus) in any sensory modality. (From APA, Thesaurus of Psychological Index Terms, 8th ed.)

The ability or act of sensing and transducing ACOUSTIC STIMULATION to the CENTRAL NERVOUS SYSTEM. It is also called audition.

The minimum amount of stimulus energy necessary to elicit a sensory response.

The perceived attribute of a sound which corresponds to the physical attribute of intensity.

AUTOMOBILES, trucks, buses, or similar engine-driven conveyances. (From Random House Unabridged Dictionary, 2d ed)

Computer-based representation of physical systems and phenomena such as chemical processes.

Ability to make speech sounds that are recognizable.

A usually four-wheeled automotive vehicle designed for passenger transportation and commonly propelled by an internal-combustion engine using a volatile fuel. (Webster, 1973)