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Hearing Safety

September 6, 2023

VISTA Partner and Volunteer Coordinator

Tara Wu

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My Story

How it happened
Immediate consequences
Long-term consequences

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How Does Hearing Work?

Awareness and processing of sounds
4 parts of the auditory system¹

Outer ear
Middle ear
Inner ear
Auditory nervous system

Auditory System Diagram by Healthy Hearing

Quick explanation of how hearing works – basically there are four parts of the auditory system, and any of those 4 parts can be damaged to result in hearing loss

Outer

visible part of ear, funnels sound into ear canal like a reverse megaphone

Middle

ear drum and tiny bones that carry sound into the ear

Inner

Where the majority of hearing loss occurs
Delicate system – once it's broke, you can't fix it
Where age-related hearing loss occurs
Where sound-related hearing loss occurs
Cochlea (means snail shell) lined with tiny hair cells
Vibrations reach hair cells, they transmit signals to your auditory nerve
Also helps you maintain your balance
Lots of people with hearing loss also have balance issues

Auditory nervous system

nerve that runs from inner ear to brainstem
How those hair cells communicate with your brain

Sound waves travel through your ear canal to your eardrum and cause it to vibrate.
The vibrations travel from your eardrum to your ossicles (tiny bones in your middle ear).
Your ossicles send the vibrations to your cochlea (a spiral cavity in your inner ear that’s lined with hair cells).
The tiny hair cells vibrate and send messages to your auditory nerve (the nerve that connects your ears to your brain).
Your brain receives this information and translates it into sound. In other words, your brain is where your sense of hearing comes to life.

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What is Hearing Damage?

Three types:

Sensorineural (inner ear)
Conductive (bones)
Mixed

You can lose:

Specific pitch recognition (lows/highs)
Discrimination
Acuity
Direction

Tinnitus

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How Hearing Loss Affects Daily Life

Sleep disruption (tinnitus)
Confusion (self and others)
Embarrassment and shame
Job performance
Can make a person look inattentive or defiant
Ageism

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Signs of Hearing Loss

You think people mumble a lot
You think certain people mumble
Your ears ring or make weird noises
It sounds like you are underwater
You are having trouble figuring out where

sounds come from

You are asking people to repeat themselves
You feel embarrassed to ask people to repeat
You are misremembering directions or feel confused

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Sounds can be HIGH or LOW in pitch

High Sounds

Water

Birds

Whistles

Violin

Young children

Electronic devices

Low Sounds

Some voices

Human heartbeat

Drums

Animal roars

Thunder

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Sounds can be SOFT or LOUD

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How is Hearing Lost?

Aging
Congenital Abnormalities
Disease
Physical trauma
Medications
Sound exposure

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Protecting Your Hearing: Basic Principles

Everyone should be doing this
You lose it, you can't get it back
Damage leads to more damage

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Can You Regain Lost Hearing?

Hearing Aids

Amplifies sound
Not perfect

Cochlear implants

Sends sound straight to auditory nerve
Bypasses faulty mechanics

Tinnitus

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Ways to Protect Your Hearing

Earplugs
Noise protecting headphones
Annual exams

Required free of charge as per

OSHA guidelines²

Take breaks from loud noises
Decrease volume if possible

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Not all Earplugs Are Created Equal

Earplugs

Wax, foam, rubber, custom
Reusable or one-use
20-60dB
Can do the following:

Reduce steady background noise
Mask all noise
Filter certain sounds
Protect against sharp bursts

Need to know how loud something is and permitted exposure times

Do some math!

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OSHA Permissible Noise Exposure Limits^{2, 3}

Too much protection is ok
Too little = insufficient
Hearing damage = ALWAYS

Duration per day (hours)	dB	Example
8	90	Hairdryer
4	95	School dance, weed eater
3	97	Pro sports games
2	100	Hand dryer
1.5	102	Bars
1	105	Leaf blower
0.5	110	Dog barking
< .25	115	Musical concert, some chainsaws
Always wear protection	>115	Gunshot, jackhammers and large power tools, jet engines, construction vehicles

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How to Interact with Someone Who Has Hearing Loss

Be patient
Avoid speaking too fast
Resist temptation to yell
Articulate, raise voice slightly, talk a bit slower
Don't cover your mouth

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References

How Hearing (Auditory Process) Works (clevelandclinic.org)

1910.95 - Occupational noise exposure. | Occupational Safety and Health Administration (osha.gov)

Noise exposure among federal wildland fire fighters - PMC (nih.gov)