CAOHC Exam Study Guide – Questions With 100% Correct Answers Updated 2024/2025.

CAOHC Exam Study Guide – Questions With 100% Correct Answers Updated 2024/2025. Unit of measurement for frequency (pitch) - answersHertz (Hz) Unit of measurement for intensity (loudness) - answers-Decibel (dB) Risk of damage from noise - answers-How loud (intensity) and how long (duration) Steady-state or continuous noise, e.g. generator - answers-Lasts 1 second or longer Impulse or Impact noise, e.g. gunfire or nail gun - answers-Lasts less than one second Parts of the outer ear - answers-Pinna and external auditory canal Parts of the middle ear - answers-Tympanic membrane, ossicles, eustachian tube CAOHC Exam Study Guide – Questions With 100% Correct Answers Updated 2024/2025 Eustachian tube (auditory tube) - answers-Tube connecting the middle ear to the pharynx and equalizes middle ear space with atmospheric pressure Conductive HL occurs here - answers-Outer or middle ear Sensorineural hearing loss - answers-Hearing loss resulting from damage to the inner ear (cochlea) or the auditory nerve Noise-induced hearing loss (NIHL) - answers-Condition caused by the destruction of hair cells, the organs responsible for hearing, as a result of sounds that are "too long, too loud, or too close"; a sensorineural hearing loss Mixed hearing loss - answers-Combination of conductive and sensorineural types in the same ear Middle ear bones (ossicles) - answers-Malleus (hammer), incus (anvil), stapes (stirrup) Possible early symptoms/signs of noise induced hearing loss - answers-Tinnitus; difficulty understanding in presence of background noise; read visual cues Auditory effects of noise - answers-NIHL; tinnitus; hyperacusis Non-auditory effects of noise - answers-annoyance sleep disturbance attention motivation stress reactions cardiovascular problems endocrine problems 3 foot rule - answers-Good rule of thumb to recognize hazardous noise exposure levels/situations: the rule is: if you have to shout at arms length (~3ft), in order to be understood over the background noise, then you're likely exposed to hazardous noise levels & should be wearing hearing protection to prevent NIHL OSHA (Occupational Safety and Health Administration) versus National institute of Occupational Safety and Heath (NIOSH) - answers-OSHA enforces regulation and NIOSH recommends best practice based on science and research Sound pressure level (SPL) versus hearing level (HL) - answers-SPL describes noise measurements taken with a sound level meter or dosimeter; HL describes Threshold levels obtained with an audiometer; 0 dB HL is not equal to 0 dB SPL Noise Dosimeter - answers-A sound measurement device used to record the amount of sound exposure over an extended period of time (usually a work day) Personal vs. Area Sound level meter - answers-Uses a microphone to sense pressure variations in sound waves; the meter converts those pressures directly into decibels; provides a noise measurement that is a snapshot in time. Time Weighted Average (TWA) - answers-An evaluation of exposures that is time-weighted over an established period. It allow the exposure levels to be averaged generally over an eight-hour time period. OSHA exchange rate - answers-5 dB; for every 5 dB you go over the PEL of 90dBA TWA you half the allowable time of exposure OSHA Action Level for noise - answers-85dBA TWA