CAOHC QUESTIONS AND ANSWERS 2024

CAOHC QUESTIONS AND ANSWERS 2024 The missions of CAOHC include: guiding industry on successful implementation of hearing conservation programs NRR calculations are based on an EPA specification that uses a withdrawn ANSI standard. true Age corrections values are determined by: Consulting tables published in Appendix F of the regulations Continuous noise is defined as noise lasting longer than: 1sec Administrative controls to limit noise exposure include which of the following? Limiting the time a worker spends at a noise source What type of hearing loss can be attributed to noise? sensorineural State hearing regulations must meet or exceed federal regulations. true If a daily calibration threshold is off by more than 5 dB, the audiometer must be acoustically calibrated. true in addition to the OSHA requirements, FRA requires what datum on audiograms? audiometer model When visually inspecting an ear canal, an otoscope should be held like a hammer. false No follow-up is required for an STS if a physician determines the loss was not caused on the job. true Audiometric testing is also known as hearing screening. false When a worker's exposure reaches the 'action level', the employer must: include the worker in the hearing conservation program Which of the following is true about banded earplugs? They are useful in intermittent noise environments What is the document MSHA requires to report hearing loss incidents? form 7000-1 FRA requires worker training within 180 days of enrollment in a hearing conservation program. true What is the amount of attenuation achieved when earplugs are worn in combination with earmuffs? 5 dB more than the higher attenuation of the two devices Which of the following is NOT an occupational noise regulatory body? CDC Hertz is a unit of? sound frequency During acoustic calibration no adjustments are made to an audiometer. true functional hearing loss is also known as pseudohypacusis. true Which of the following is NOT a datum OSHA requires on audiograms? workers birthday OSHA defines a 'persistent STS' as an STS lasting more than: 21 days 30 days 45 days 60 days none of the above What is the first thing you should do when fitting earplugs? check canal for any occlusions Properly fitted earmuffs should cause the wearer's voice to sound deeper or muffled. true Which of the following statements regarding NRR are true? Real world attenuation is, on average, about one-third to one-half of the NRR A higher NRR does not accurately reflect better attenuation in the workplace Earplug attenuation varies widely among a group of wearers, regardless of NRR all of the above Which of the following is a method to verify proper plug insertion? Acoustic check observing noise level change when cupping hands over ear Acoustic neuromas can manifest as assymetric or unilateral loss. true OSHA requires exhaustive calibration of audiometers: every 2yrs Earmuffs should be cleaned with solvents regularly to prevent particulate build-up. false Which of the following is NOT an element of a Hearing Conservation Program? annual spectrum testing What decibel level is the action level? 85dB 8hr TWA When performing a test it is best practice to: Vary the interval between tone presentations FRA requires written notification of a Standard Threshold Shift within how many days? 30 MSHA requires written notification of a Standard Threshold Shift within how many days? 10 What type of tone is employed in audiometry? pure NIOSH recommends against using age correction: true A bio-acoustic simulator is used to: Take the place of a human when peforming daily calibration Which of the following is MSHA's reporting criterion? The hearing level average change at 2K, 3K, and 4K is greater or equal to 25 dB worse than the baseline The frequency of sound is perceived as? pitch OSHA's 1910.95 regulation requires written notification of a Standard Threshold Shift within how many days? 21 a bio-acoustic simulator is used to: take the place of a human when preforming daily calibration Sound level meters are the best tool to measure noise exposure for workers whose exposures vary during the course of a shift. false OSHA clearly defines what is meant by 'problem audiogram'. false physiological effects of noise noise induced hearing loss, tinnitus, hypertension, heart disease psychological effects of noise easily startled, annoy, disrupt concentration, sleep disturbance characteristics of noise induced hearing loss usually bilat, always sensorineural, affects high freq first (4000Hz), loss usually not greater than 75 dB, greatest in first 10-15yrs primary determiners of damage of noise induced hearing loss (NIHL) duration and intensity of sound, temporary threshold shifts (TTS) conductive hearing loss breakdown in transmission of sound through OUTER & MIDDLE ear *treatable sensorineural hearing loss damage to INNER ear or nerves that carry signals from inner ear to brain *preventable, irreversible mixed hearing loss conductive and sensorineural losses take place at same time outer ear structures auricle (pinna) & external auditory meatus (canal) outer ear-auricle (pinna) helps localize sound (req both ears), collects and funnels sound waves into external auditory canal outer ear-external auditory meatus (canal) s shaped tube, leads to tympanic membrane (eardrum) outer ear problems cerumen impaction, otitis externa (outer ear infxn), congenital malformation, foreign body *causes CONDUCTIVE hearing loss tympanic membrane thin, boundary btwn OUTER and MIDDLE ear middle ear structures malleus, incus, stapes-3 smallest bones in body eustachian tubes-ventilates middle ear, NOT part of hearing middle ear problems otitis media (middle ear infxn) perforated tympanic membrane (affects hearing of low freq) cholesteatoma (growth in middle ear) otosclerosis (stiffening of ossicles) disarticulated ossicles (broken joint) eustachian tube disfxn *cause CONDUCTIVE hearing loss inner ear structures cochlea (hearing) & vestibular system (balance) cannot examine in live pt inner ear contains 2 primary structures: _ & _ hearing balance inner ear problems noise (NIHL) presbycusis (age related hearing loss) ototoxicity (chemical induced) disease (measles/mumps/MENIERES) congenital sudden idiopathic sensorineural hearing loss *causes PERMANENT hearing loss Auditory nerve electrical signals from hair cells are transmitted to auditory nerve, passes info to brain centers to process them (speech, music, other) ototoxins ex: solvents, metals, asphyxiants (carbon monox), meds (diuretics, aspirin, chemo, antibiotics) *cause SENSORINEURAL hearing loss OSHA def of sound any pressure change in air, water, or other medium which the human ear can detect 4 things necessary for sound 1) source of energy (sets vibrating body in motion-lungs/electricity) 2) vibrating body (vocal cords, microphone, tuning fork) 3) medium (gas, fluid solid) 4) receiver (ear/microphone) necessary for sound pathway lung vocal cord air ear compression sound waves area of positive pressure rarefaction sound waves area of negative pressure time to complete an entire sound wave cycle = one _ period frequency pitch intensity loudness duration time hertz (Hz) frequency high frequency sounds more CPS (cycles per second) low frequency sounds fewer CPS (cycles per second) range of human hearing 20-20,000Hz