CAOHC Exam Study Questions &
Answers 2024 Latest Update!!
Unit of measurement for frequency (pitch) - ANSWER Hertz (Hz)
Unit of measurement for intensity (loudness) - ANSWER Decibel (dB)
Risk of damage from noise - ANSWER How loud (intensity) and how long (duration)
Steady-state or continuous noise, e.g. generator - ANSWER Lasts 1 second or longer
Impulse or Impact noise, e.g. gunfire or nail gun - ANSWER Lasts less than one second
Parts of the outer ear - ANSWER Pinna and external auditory canal
Parts of the middle ear - ANSWER Tympanic membrane, ossicles, eustachian tube
Eustachian tube (auditory tube) - ANSWER Tube connecting the middle ear to the
pharynx and equalizes middle ear space with atmospheric pressure
Conductive HL occurs here - ANSWER Outer or middle ear
Sensorineural hearing loss - ANSWER Hearing loss resulting from damage to the inner
ear (cochlea) or the auditory nerve
Noise-induced hearing loss (NIHL) - ANSWER 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 - ANSWER Combination of conductive and sensorineural types in
the same ear
Middle ear bones (ossicles) - ANSWER Malleus (hammer), incus (anvil), stapes (stirrup)
Possible early symptoms/signs of noise induced hearing loss - ANSWER Tinnitus;
difficulty understanding in presence of background noise; read visual cues
Auditory effects of noise - ANSWER NIHL; tinnitus; hyperacusis
Non-auditory effects of noise - ANSWER annoyance
sleep disturbance
attention
motivation
stress reactions
, cardiovascular problems
endocrine problems
3 foot rule - ANSWER 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) - ANSWER OSHA enforces regulation and
NIOSH recommends best practice based on science and research
Sound pressure level (SPL) versus hearing level (HL) - ANSWER 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 - ANSWER 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 - ANSWER 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) - ANSWER 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 - ANSWER 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 - ANSWER 85dBA TWA
Sound Level Meter A-weighted Scale - ANSWER OSHA requires this scale as it
resembles how the human ear responds to sound (humans hear best from 500 Hz to
4000 Hz
Human Frequency Response at Birth - ANSWER 20 Hz to 20,000 Hz (20 kHz)
Human speech frequency range - ANSWER 250 Hz to 4000 Hz
Elements of a Hearing Conservation Program - ANSWER Noise hazard assessment;
engineering/administrative controls; annual hearing monitoring; annual
training/education; hearing protection; recordkeeping
Answers 2024 Latest Update!!
Unit of measurement for frequency (pitch) - ANSWER Hertz (Hz)
Unit of measurement for intensity (loudness) - ANSWER Decibel (dB)
Risk of damage from noise - ANSWER How loud (intensity) and how long (duration)
Steady-state or continuous noise, e.g. generator - ANSWER Lasts 1 second or longer
Impulse or Impact noise, e.g. gunfire or nail gun - ANSWER Lasts less than one second
Parts of the outer ear - ANSWER Pinna and external auditory canal
Parts of the middle ear - ANSWER Tympanic membrane, ossicles, eustachian tube
Eustachian tube (auditory tube) - ANSWER Tube connecting the middle ear to the
pharynx and equalizes middle ear space with atmospheric pressure
Conductive HL occurs here - ANSWER Outer or middle ear
Sensorineural hearing loss - ANSWER Hearing loss resulting from damage to the inner
ear (cochlea) or the auditory nerve
Noise-induced hearing loss (NIHL) - ANSWER 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 - ANSWER Combination of conductive and sensorineural types in
the same ear
Middle ear bones (ossicles) - ANSWER Malleus (hammer), incus (anvil), stapes (stirrup)
Possible early symptoms/signs of noise induced hearing loss - ANSWER Tinnitus;
difficulty understanding in presence of background noise; read visual cues
Auditory effects of noise - ANSWER NIHL; tinnitus; hyperacusis
Non-auditory effects of noise - ANSWER annoyance
sleep disturbance
attention
motivation
stress reactions
, cardiovascular problems
endocrine problems
3 foot rule - ANSWER 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) - ANSWER OSHA enforces regulation and
NIOSH recommends best practice based on science and research
Sound pressure level (SPL) versus hearing level (HL) - ANSWER 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 - ANSWER 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 - ANSWER 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) - ANSWER 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 - ANSWER 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 - ANSWER 85dBA TWA
Sound Level Meter A-weighted Scale - ANSWER OSHA requires this scale as it
resembles how the human ear responds to sound (humans hear best from 500 Hz to
4000 Hz
Human Frequency Response at Birth - ANSWER 20 Hz to 20,000 Hz (20 kHz)
Human speech frequency range - ANSWER 250 Hz to 4000 Hz
Elements of a Hearing Conservation Program - ANSWER Noise hazard assessment;
engineering/administrative controls; annual hearing monitoring; annual
training/education; hearing protection; recordkeeping
