Basic Audiology: Understanding the Xs and Os Developed by: Sheila Hitchen Tweaked by: Cheryl Davis

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Basic Audiology Understanding theXs and
OsDeveloped by Sheila HitchenTweaked by
Cheryl Davis
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The Issue for VR

• 28 million people in US have a hearing loss (10)
• HOH population unemployed due to disability
  22.5
• The rate is essentially constant regardless of
  whether the loss is in one or both ears
• Hearing women stay in labor force 9 years longer
  than hard of hearing women
• 17 more hard of hearing female workers aged
  45-54 exit the labor force
• People leave jobs because of
• Inability to continue to carry out duties
• Social difficulties and isolation

Data from U.S. Census Bureau the Center for
Bilingual Education and Research, Arizona State
University.
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Who Would You Hire or Promote?

• Worker 1
• Depressed
• Defensive/Paranoid
• Poor self image
• Poor social skills
• Poor listening skills
• Feels like they have no control

• Worker 2
• Not depressed
• Less defensive/ paranoid
• Normal self image
• Normal social skills
• Normal listening skills
• Feels like they are in control

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Myths Misunderstandings

• Whats the big deal?
• You hear pretty good.
• You speech read, right?
• Your hearing aids fix it.
• You can hear if you want to.
• You dont need accommodations
• Your speech is clear, so you hear well,
• You heard me fine in my office,
• You talked to me on the phone.

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You want me to what???

• Definitely understood
• Fairly certain he understood
• Certain he did not understand
• Certain he understood (but didnt)
• Doesnt know he didnt hear

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I have an 80 hearing loss.
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Individual Experience Includes

• Hearing loss
• binaural or monaural
• varies in severity (dB) and frequency (Hz)
• may fluctuate or be progressive
• Age at onset of loss
• Acceptance/coping strategies
• Support structure
• Hearing aid/T-coil use/AT use
• Identity
• Deaf ?Hard of Hearing
• Late Deafened ?Cochlear Implant User

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How Hearing Works
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Conductive Hearing Loss
Sound does not move into inner ear
efficiently. Due to a problem in either outer or
middle ear. May be medically or surgically
treated or cured. Inner ear works
fine. Amplification may help to get sound through
the auditory system.
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Sensorineural Hearing Loss
Sound is not interpreted efficiently by inner
ear. (Louder doesnt help!) May be due to hair
cell/nerve damage. May be due to problem with
auditory nerve.
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Cochlear Structure
Low Frequency speech sounds are fewer than high
frequency. People have difficulty hearing words
in two competing signals (cocktail party effect)
High frequency cells take the brunt of the
day-to-day damage most people lose high
frequency hearing first. People hear the
sounds, but cant make out the words "Speak up
and quit mumbling!!"
Low Frequency
High Frequency
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Normal Hearing Looks Like
Normal Inner Outer Hair Cells
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Sensorineural Hearing Loss
Going
Going
GONE
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Causes

• Congenital
• Maternal Rubella
• Genetic Syndromes
• Usher Syndrome
• Waardenburg Syndrome
• Illness and Infection
• Measles, Meningitis
• Otitis Media
• Ototoxic Medication
• Noise Exposure

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At present exposure limits, one in four people
will develop a permanent hearing loss as a result
of their occupational exposure to noise hazards.
Data courtesy of the National Institute of
Occupational Health and Safety
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Causes Presbycusis (Age Related)

• Progressive sensorineural loss
• High frequencies first
• 55 to 65 high frequencies in the speech range
  begin to be affected
• Other considerations
• Macular Degeneration
• Manual Dexterity Issues

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Other IssuesTinnitus

• Characterized by ringing, rushing, buzzing sounds
  in ears
• Due to damage to cochlear hair cells
• Diet and stress management may help control
  symptoms
• Incurable
• Some use maskers to
• block ringing
• www.ata.org

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Other IssuesMenieres Disease

• Fluctuating
• Hearing loss
• Rotational vertigo
• Tinnitus
• Sense of Aural Fullness
• Balance
• Visual
• Tactile
• Vestibular system
• http//www.menieresinfo.com
• http//www.menieres.org
• http//www.vestibular.org

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Reading the Audiogram
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Components of aHearing Test
Speech Audiometry
Air Bone Conduction
Legend
Comments
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The Audiogram
Bass
Treble

• Frequency is measured in hertz (Hz)
• Common range shown is 250 Hz to 8000 Hz
• Low numbers low tones
• High numbers high tones

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The Audiogram

• Volume is measured in decibels (dB)
• The higher the line, the better the clients
  hearing
• 90 dB loss does not indicate the person is 90
  Deaf!

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The Audiogram

• X left O right ear
• Normal 0-20 dB
• Mild 20-40 dB
• Moderate 40-70 dB
• Severe 70-90 dB
• Profound 90 dB
• ALL levels have vocational impacts!

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Air Conduction
Tests the ability of sound to be processed by the
hearing mechanism. Shows severity and frequency
of the individuals loss.
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Bone Conduction
Tests the ability of the middle ear to conduct
sound to the inner ear. Used to determine the
type of loss.
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Tympanometry
Tests the function of ear drum and air pressure
in middle ear A diagnostic tool for middle ear
problems.
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Speech Audiometry

• How well does person hear speech?
• Speech Reception Threshold
• Speech Detection Threshold
• Discrimination Score
• Most Comfortable Level
• Uncomfortable Level
• See What is a Hearing Aid Evaluation on WROCC
  website

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Options for Amplification
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Hearing Aids Simplified
Microphonepicks up sound Amplifiermakes sound
louder Speakersends sound down ear canal Bigger
more space for battery!
ITE
BTE
ITC
CIC
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Common Styles

• Behind the Ear (BTE)
• In the Ear (ITE)
• In the Canal (ITC)
• Completely in the Canal (CIC)
• Body Aids
• CROS
• Contralateral Routing of Signal

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Circuit Technology(Analog vs. Digital)

• Least Expensive
• Conventional
• Non-programmable linear (analog)
• Programmable
• Analog (with screwdriver)
• Digital (with computer)
• Digital Signal Processing
• Most Expensive

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Hearing Aid Terminology

• Programmable means how you set all the options or
  tune the hearing aid
• Program means different settings for different
  listening situations (e.g., music, using the
  phone/telecoil, in noisy situations)
• Channel means how many different ranges of
  frequencies are amplified

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Hearing in Noise

• Signal to noise ration problem
• Directional Microphones
• Noise reduction
• Assistive Listening Devices
• Telecoils
• Not as sensitive as hearing aids
• Susceptible to electromagnetic interference
• Direct Audio Input
• FM Boot

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Two Hearing Aids Vs. One

• Better hearing in noise
• Head Shadow Effect
• Improved localization
• Deterioration of unaided ear
• Improved understanding of speech
• Save battery power
• Less tiring
• Better balance of sound
• Help mask tinnitus

• REMEMBERUnemployment rates are about the same
  with a loss in one or both ears!
• Differentiated
• Right ear cells respond more to speech
• Left ear cells respond more to music

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What About Cochlear Implants?
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T
The microphone sends sounds to the processor,
which codes the sounds into useful speech, music,
etc.
Cochlear implants are designed to by-pass the
non-functioning cochlear hair cells and provide
direct stimulation to the auditory nerve.
Some sounds are easier for the brain to figure
out than others. Environmental sounds are less
complex that combinations of speech sounds.
Sounds are transmitted through the skin to the
receiver/stimulator via the magnetic headset.
The electrodes then stimulate the auditory nerve
which sends the signals to the brain. The brain
interprets these electrical signals into sounds.
The codes are then converted to electrical
signals which activate the coiled electrode
arrays in the cochlea.
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What About Cochlear Implants?

• Destroys existing Cochlear cells
• Does not restore normal hearing
• Technology constantly improving
• Does not change the individuals identity

• Auditory Prosthesis
• Surgical procedure
• Medical clearance required
• Replaces hearing aid
• Can restore independence for late-deafened people

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How do You Define Success?

• Environmental sounds
• Improved speech reading ability
• Speech of familiar others
• Speech of strangers
• Able to enjoy music
• Able to use phone

• Personal stories
• BB WH
• KS
• SR
• MT

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Cochlear Implants

• 1970s CIs will never work
• 1980s CI users will never understand speech
• 1990s They will never appreciate music
• 2000s They will never hear like normal-hearing
  people do
• Next Bilateral implantation?
• Note about 45,000 people have CIs to date.

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Resources

• SHHH-Self Help for Hard of Hearing People
• www.shhh.org (many materials available)
• ALDA-Association of Late Deafened Adults
• www.alda.org
• CIAI-Cochlear Implant Association International
• www.cici.org
• NAD-National Association of the Deaf
• www.nad.org
• WROCC Outreach Site at WOU
• www.wou.edu/nwoc/leavitt.htm
• www.wou.edu/wrocc and click on Training Materials
• Hearing Aid Primer
• What is a Hearing Aid Evaluation?
• How to Read an Audiogram

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Resources

• Sound and Fury, video by Josh Aronson, 2000
• Wired for Sound, by Bev Biderman
• Cochlear Implant Forum Listserv Email
• To listser_at_yorku.ca
• From (Your e-mail address)
• Subject (Leave it blank)
• Message Subscribe ci (your name)
• Cochlear Corporation www.cochlear.com
• Advanced Bionics (Clarion) www.advancedbionics.co
  m
• Med-El www.med-el.com
• www.hearinglosshelp.com/twohearingaids.htm
• www.hearinghealth.org
• Consumers Guide to Hearing Aids
• www.beyondhearingaids.com
• evaluation of consumers environment
• Survivors Manual http//shhhor.org/survivor_manu
  al.pdf