External Hearing Aids Are of No Use to an Individual

question 656

Multiple Choice

External hearing aids are of no use to an individual with

• A)damage to the auditory ossicles.
• B)a sensorineural hearing loss.
• C)a conductive hearing loss.
• D)damage to the tympanic membrane.

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Definitions:

Treadle Valve

A foot-operated valve that controls the flow of air in a pneumatic system, often used in braking systems of heavy vehicles.

Inversion Valve

A normally open air brake valve used for emergency applications of tractor brakes for a one-time stop during a total system failure. Hold-off air is dumped in relation to application pressure so that spring chamber force can effect emergency service braking. Incorporated in some modulating valves.

Tractor Protection Valve

A safety valve in commercial vehicles that prevents air loss in the tractor in the event of a trailer breakaway or air line failure.

FMVSS-121 Compliant

FMVSS-121 compliant means adhering to the Federal Motor Vehicle Safety Standard 121, relating to air brake systems in heavy vehicles.