CAOHC Exam Study Guide Latest Update Rated A+

CAOHC Exam Study Guide Latest Update Rated A+ Unit of measurement for frequency (pitch) Hertz (Hz) Unit of measurement for intensity (loudness) Decibel (dB) Risk of damage from noise How loud (intensity) and how long (duration) Steady-state or continuous noise, e.g. generator Lasts 1 second or longer Impulse or Impact noise, e.g. gunfire or nail gun Lasts less than one second Parts of the outer ear Pinna and external auditory canal Parts of the middle ear Tympanic membrane, ossicles, eustachian tube Eustachian tube (auditory tube) Tube connecting the middle ear to the pharynx and equalizes middle ear space with atmospheric pressure Conductive HL occurs here Outer or middle ear Sensorineural hearing loss Hearing loss resulting from damage to the inner ear (cochlea) or the auditory nerve Noise-induced hearing loss (NIHL) 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 Combination of conductive and sensorineural types in the same ear Middle ear bones (ossicles) Malleus (hammer), incus (anvil), stapes (stirrup) Possible early symptoms/signs of noise induced hearing loss Tinnitus; difficulty understanding in presence of background noise; read visual cues Auditory effects of noise NIHL; tinnitus; hyperacusis Non-auditory effects of noise annoyance sleep disturbance attention motivation stress reactions cardiovascular problems endocrine problems 3 foot rule 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) OSHA enforces regulation and NIOSH recommends best practice based on science and research Sound pressure level (SPL) versus hearing level (HL) 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 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