PA F08.ppt [Read-Only] - eta.health.usf.edueta.health.usf.edu/EOH6357/noiseslides.pdf · Usually...
Transcript of PA F08.ppt [Read-Only] - eta.health.usf.edueta.health.usf.edu/EOH6357/noiseslides.pdf · Usually...
NoiseNoise
Q13What symptom is experienced by those who have tinnitus?
a. Difficulty in hearing low-frequency soundsy g q y
b. Constant dull earache
c. Ringing or buzzing sound in the head
d. Sharp pain in the eard. Sharp pain in the ear
e. Total deafness
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Q14Why is noise-induced hearing loss permanent?
a. Causes eardrum to rupturep
b. Cause degeneration of the auditory nerve
c. Destroys hair cells in the Organ of Corti
d. Produces fine cracks in the delicate bones of thed. Produces fine cracks in the delicate bones of the middle ear
e. Produces severe inflammation of the auditory canal
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y
Q15Which recreational activity, performed for two-hours, is most likely to cause a noise-induced hearing loss?
a. Attending a rock concert
b. Listening to music with head phones
c. Riding motorcycles without a helmet
d. Target shooting
e. Attending class
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g
Noise Overview
Structure & Function of Hearing
Definition
Properties
Regulation
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Regulation
The Hearing Mechanism
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What happens if …
a mime falls in the woods and there is no one to hear him?
Does he make a noise?Does he make a noise?
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What is Noise?Psychological View: Unwanted or useless sounds in the environment
Physical View: All sounds
Limits Based on EffectsDamage to hearingDamage to hearingMasking of desirable soundsAnnoyance and fatigue
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Properties of Sound I
Sound Waves
pressure deviationsth t th h ithat move through air
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Properties of Sound II
Frequency = Number of Waves per SecSingle Frequency Perceived as a ToneSingle Frequency Perceived as a ToneReported as Hertz (Hz)Most Sounds Are a Composite ofMost Sounds Are a Composite of
Frequencies
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Properties of Sound III
Intensity = Pressure Amplitude of the WavePerceived as LoudnessSound Pressure Reported in deciBels (dB)Sound Pressure Reported in deciBels (dB)
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Sound Levels160 dB – Jet engine
140 dB – Pain thresholdPerceived LoudnessDoubles Every 10 dB
120 dB – Riveter
100 dB T k t ffi
y
100 dB – Truck traffic
80 dB – Noisy office80 d o sy o ce
60 dB – Talking Energy On the Ear
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gyDoubles Every 3 dB
Q16Sound is best described by
A. a group consensus of desirability
B d iB lB. deciBels
C pitchC. pitch
D intensity and frequency
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D. intensity and frequency
Hearing Loss
Temporary Threshold ShiftGenerally related to acute exposure (e.g.,Generally related to acute exposure (e.g.,
hunting, concerts)Ringing may be perceivedg g y pMay last several daysRepeated episodes may require hazardRepeated episodes may require hazard
evaluation
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Hearing Loss cont.
Permanent Threshold ShiftSensorineural Damage (Inner Ear)Sensorineural Damage (Inner Ear)IrreversibleRisk is related to life-time exposureRisk is related to life time exposureUsually compared against PresbycusisLosses begin around 4000 HzLosses begin around 4000 HzBWOM Limit = 0.00003 mW/cm2
(1000 Hz for 2000 h/yr)
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(1000 Hz for 2000 h/yr)
Other Effects of Noise
Reduction or Loss of CommunicationsAccidents, quality controlAccidents, quality control
Secondary Health EffectsSecondary Health EffectsStressWork PerformanceWork PerformanceSleep Disruption
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Q17What should drive community noise limits?
A. Potential for hearing loss
B I d t i l dB. Industrial needs
C Personal tastes of city councilC. Personal tastes of city council
D General annoyance
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D. General annoyance
Noise Standards
Sensitivity Depends on Frequency
Measurement Adjusted by FrequencyA S l (dBA)A-Scale (dBA)
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Occupational Noise Standards
Regulatory Agency: Occupational Safety and Health Administration (OSHA)( )Driven by Hearing LossStandards based on chronic and acuteStandards based on chronic and acute
exposure85 / 90 dBA for eight-hour dayg y
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Environmental Noise
Driven by Local and Federal Regulations
LocalC it M i i l R l tiCommunity: Municipal RegulationsLimits on Noise Levels, Sources and
LocationsLocationsTime of Day Limits
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Regulating EnvironmentalRegulating Environmental Noise
Environmental Protection Agency (EPA) Noise Control Act (1972): Established noise limits and
draft legislation for noise related product labeling Quiet Communities Act (1978): Amended the Noise
Control Act, provided for civil penalties and private citizen enforcement procedures, and assistance in developing local regulationsdeveloping local regulations
Dept. of Housing and Urban Development (HUD)Federal Highway Administration (FHWA)Federal Aviation Administration (FAA)Federal Transit Administration (FTA)American Public Transit Association (APTA)
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American Public Transit Association (APTA)
Questions?Questions?