Sound

sensation resulting from stimulation of the auditory mechanism by air waves or vibration

Noise

any unwanted sound

requirements for sound

source of vibration, Energy, A Median Air,A Receiver

Frequency

Pitch, measured in Hz

Human ear can detect frequencies in the ranges of

20- 20,000 Hz

Duration

Time

dBA SPL

a sound pressure level measurement

Spectrum

Quality

Intensity

Loudness

what is hazardous noise?

more than 85 dBA
140 dB(P)

What frequencies is the human ear most sensitive to?

20- 20,000 Hz

what two factors will determine whether noise is hazardous to hearing?

Intensity and duration

Outer ear

Pinna

S- shaped for protection

Middle ear

Ear drum- Tympanic Membrane- sound into mechical
Ossicles- malleus, Incus, and stapes- transfers

Inner ear

Cochlea- changes mechical to electrical energy

Vestibular system

balances your body

Auditory Brain

Carries signals to the brain

Conductive

dysfunction of the outer and/ or middle ear
treatment- usually temporary and antibiotics

SensoriNeural hearing loss (SNHL)

a dysfunction of the inner ear and auditory nerve
Permanent and untreatable

Noise induced hearing injury (NIHI)

hazardous exposure levels
Permanent and untreatable

Mixed Hearing loss

Both conductive and SNHL

Central hearing loss

auditory processing disorder

Non- Organic

No medical and/or FAKING

Someone with a classic noise-induced hearing loss will likely have their worst at?

4000 Hz

Threshold

sound that a person can hear at least 50% of the time

STS

Significant Threshold Shift
-/+ 10 dBs avg threshold change 2000, 3000, and 4000 Hz in either ear

Audiometric Zero

0 dB - normal hearing young adult

Audiogram

record of a person's pure-tone hearing threshold levels

Patient info

SSN, NAME, GENDER, DOB, Rank, MOS, UIC, Phone number

Demographic info

SSN, NAME, CERT

DD 2215

Reference Audiogram
noise free 14 hours
initial hearing test
re-coming in government job

DD 2216

Hearing conservation data
-90 day, annual, pre-deployment, post-deployment, other, and termination, Follow up 1 and 2

Negative STS

Follow up and neg again then ref
Follow up and same threshold then stays the same

Pos STS

follow up cant be same day as annual
follow up completed after 14 free of sound
follow up 1 pos then follow up 2
follow up 2 pos then ref to audiologist

Non-hearing conservation test

individual not enrolled in army hearing program

High frequency hearing loss

noise-notch

Da PAM 40-501

Hearing conservation program

Impact of noise-induced hearing loss

Survivability and lethality

4 P's

Permanent, painless, progressive, and preventable

Inverse square law

army is a doubling hazard for each 3 dB increases in level decreases time by half

Sound decays _______ for every doubling of distance

6 dB

DD form 2217

recorded and printed monthly