CAOHC FINAL EXAM 2026 QUESTIONS AND SOLUTIONS
GRADED A+
✔✔Noise doubling rule - ✔✔If you add two identical noise sources you add 3dB to the
Level (100 dB + 100 dB = 103 dB)
✔✔Administrative noise controls - ✔✔Changes made by employer such as changing
work schedules to reduce noise hazard risk to employees
✔✔OSHA standard threshold shift - ✔✔10dB average change at 2000 Hz, 3000 Hz,
and 4000 Hz, when compared to a baseline , in one or both ears
✔✔OSHA Recordable Standard Threshold Shift for Hearing Loss - ✔✔3 criteria: 10dB
average shift at 2, 3, and 4kHz, compared to baseline, AND 25 dB average HL at 2, 3,
and 4 kHz in the same ear on current audiograms, AND determined to be work-related
✔✔Collapsing ear canal - ✔✔Occurs naturally in some individuals during audiometric
testing-earphones cause auricle to move forward collapsing the canal and causing an
artificial hearing loss; Insert earphones should be used
✔✔Cochlea - ✔✔A coiled, bony, fluid-filled tube in the inner ear through which sound
waves trigger nerve impulses; damage from hazardous noise occurs here.
✔✔Microprocessor audiometer - ✔✔Automated computer controlled audiometer
✔✔Tinnitus - ✔✔A jingling; a ringing or buzzing in the ear
✔✔Type of hearing test done by a certified occupational Hearing conservationist
(COHC) - ✔✔Air Conduction Pure Tone Threshold Test
✔✔Hearing Threshold Level (HTL) are recorded on this - ✔✔Audiogram (can be serial
or graphic)
✔✔Baseline Hearing Test Must Be Done Within - ✔✔6 months of starting employment
(exception for mobile vans is up to 1 year)
✔✔Type of Hearing Loss that is treatable (medically or surgically) - ✔✔Conductive
hearing loss
✔✔Temporary Threshold Shift (TTS) - ✔✔Brief exposure to intense noise that will
ordinarily recover with auditory rest
✔✔Hearing Thresholds Tested are: - ✔✔500, 1000, 2000, 3000, 4000, and 6000 Hz;
8000 Hz is optional but recommended.
, ✔✔Audiometric zero is: - ✔✔0 dB HL; this is not an absence of sound
HL scale has been normalized to healthy adult hearing
✔✔Vertical axis on a graphic Audiogram shows this: - ✔✔Intensity levels which are
measured in Decibels (softest at the top, loudest at the bottom)
✔✔Horizontal axis on a graphic Audiogram shows this: - ✔✔Frequencies which are
measured in Hertz (low to high going from left to right)
✔✔Hearing Baselines are reestablished when you have an STS because: - ✔✔You
don't want to identify the same shift each year
✔✔#Days to notify individual of an STS in writing - ✔✔21 days
✔✔OSHA versus NIOSH Noise Permissible Exposure Limit (PEL) - ✔✔90 dBA PEL for
OSHA; 85 dBA PEL recommended by NIOSH
✔✔OSHA recommendations for Audiometric Records - ✔✔Maintain for duration of
employment; NIOSH recommends duration of employment + 30 years
✔✔Sound Level Meter Microphone Type Required by OSHA - ✔✔Minimum of Type 2
microphone
✔✔Formable Earplugs are: - ✔✔Disposable when no longer return to shape and soiled
✔✔Pre-formed earplugs: - ✔✔Can be washed with mild soap and water and reusable
✔✔Noise muff cushions - ✔✔Should completely cover ear and seal against the face;
cushions should be replaced when damaged and no longer seal effectively.
✔✔Hearing Aids and Hearing Test - ✔✔Tests are to be done without hearing aids
✔✔Function of the Outer Ear - ✔✔Collecting sound and sending it to the eardrum
through the auditory canal
✔✔Function of the Middle Ear - ✔✔Amplification of sound; lever action of the ossicular
chain and the mismatch in size of eardrum and oval window amplify sound about 10
times
✔✔Function of the Inner Ear - ✔✔Convert mechanical sound waves to neural impulses
that can be recognized by the brain for hearing and balance
✔✔This type of hearing loss is treatable - ✔✔Conductive hearing loss
GRADED A+
✔✔Noise doubling rule - ✔✔If you add two identical noise sources you add 3dB to the
Level (100 dB + 100 dB = 103 dB)
✔✔Administrative noise controls - ✔✔Changes made by employer such as changing
work schedules to reduce noise hazard risk to employees
✔✔OSHA standard threshold shift - ✔✔10dB average change at 2000 Hz, 3000 Hz,
and 4000 Hz, when compared to a baseline , in one or both ears
✔✔OSHA Recordable Standard Threshold Shift for Hearing Loss - ✔✔3 criteria: 10dB
average shift at 2, 3, and 4kHz, compared to baseline, AND 25 dB average HL at 2, 3,
and 4 kHz in the same ear on current audiograms, AND determined to be work-related
✔✔Collapsing ear canal - ✔✔Occurs naturally in some individuals during audiometric
testing-earphones cause auricle to move forward collapsing the canal and causing an
artificial hearing loss; Insert earphones should be used
✔✔Cochlea - ✔✔A coiled, bony, fluid-filled tube in the inner ear through which sound
waves trigger nerve impulses; damage from hazardous noise occurs here.
✔✔Microprocessor audiometer - ✔✔Automated computer controlled audiometer
✔✔Tinnitus - ✔✔A jingling; a ringing or buzzing in the ear
✔✔Type of hearing test done by a certified occupational Hearing conservationist
(COHC) - ✔✔Air Conduction Pure Tone Threshold Test
✔✔Hearing Threshold Level (HTL) are recorded on this - ✔✔Audiogram (can be serial
or graphic)
✔✔Baseline Hearing Test Must Be Done Within - ✔✔6 months of starting employment
(exception for mobile vans is up to 1 year)
✔✔Type of Hearing Loss that is treatable (medically or surgically) - ✔✔Conductive
hearing loss
✔✔Temporary Threshold Shift (TTS) - ✔✔Brief exposure to intense noise that will
ordinarily recover with auditory rest
✔✔Hearing Thresholds Tested are: - ✔✔500, 1000, 2000, 3000, 4000, and 6000 Hz;
8000 Hz is optional but recommended.
, ✔✔Audiometric zero is: - ✔✔0 dB HL; this is not an absence of sound
HL scale has been normalized to healthy adult hearing
✔✔Vertical axis on a graphic Audiogram shows this: - ✔✔Intensity levels which are
measured in Decibels (softest at the top, loudest at the bottom)
✔✔Horizontal axis on a graphic Audiogram shows this: - ✔✔Frequencies which are
measured in Hertz (low to high going from left to right)
✔✔Hearing Baselines are reestablished when you have an STS because: - ✔✔You
don't want to identify the same shift each year
✔✔#Days to notify individual of an STS in writing - ✔✔21 days
✔✔OSHA versus NIOSH Noise Permissible Exposure Limit (PEL) - ✔✔90 dBA PEL for
OSHA; 85 dBA PEL recommended by NIOSH
✔✔OSHA recommendations for Audiometric Records - ✔✔Maintain for duration of
employment; NIOSH recommends duration of employment + 30 years
✔✔Sound Level Meter Microphone Type Required by OSHA - ✔✔Minimum of Type 2
microphone
✔✔Formable Earplugs are: - ✔✔Disposable when no longer return to shape and soiled
✔✔Pre-formed earplugs: - ✔✔Can be washed with mild soap and water and reusable
✔✔Noise muff cushions - ✔✔Should completely cover ear and seal against the face;
cushions should be replaced when damaged and no longer seal effectively.
✔✔Hearing Aids and Hearing Test - ✔✔Tests are to be done without hearing aids
✔✔Function of the Outer Ear - ✔✔Collecting sound and sending it to the eardrum
through the auditory canal
✔✔Function of the Middle Ear - ✔✔Amplification of sound; lever action of the ossicular
chain and the mismatch in size of eardrum and oval window amplify sound about 10
times
✔✔Function of the Inner Ear - ✔✔Convert mechanical sound waves to neural impulses
that can be recognized by the brain for hearing and balance
✔✔This type of hearing loss is treatable - ✔✔Conductive hearing loss
