Download Unfair Hearing Test

Basic Audiology:
Understanding the
Xs and Os
Developed by: Sheila Hitchen
Tweaked by: Cheryl Davis
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.
Who Would You
Hire or Promote?
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Worker #1
Depressed
Defensive/Paranoid
Poor self image
Poor social skills
Poor listening skills
Feels like they have
no control
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Worker #2
Not depressed
Less defensive/
paranoid
Normal self image
Normal social skills
Normal listening skills
Feels like they are in
control
Myths & Misunderstandings
• “What’s the big deal?
You hear ‘pretty good.’”
• “You speech read, right?”
• “Your hearing aids ‘fix’ it.”
• “You can hear if you want to.”
• “You don’t need accommodations…
– Your speech is clear, so you hear well,
– You heard me fine in my office,
– You talked to me on the phone.”
You want me to what???
• Definitely understood
• Fairly certain he understood
• Certain he did not understand
• Certain he understood (but didn’t)
• Doesn’t know he didn’t hear
“I have an 80% hearing loss.”
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125
250 500
750
1K 1.5K 2K
3K
Zv
20
40
50
60
70
80
90
100
110
120
6K
f
10
30
4K
j
S
mdb Ia
Nel
ng
u
o
r
Ph
G
Ch
sh
K
8K
th
Individual Experience Includes:
• Hearing loss
– binaural or monaural
– varies in severity (dB) and frequency (Hz)
– may fluctuate or be progressive
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Age at onset of loss
Acceptance/coping strategies
Support structure
Hearing aid/T-coil use/AT use
Identity
– Deaf
– Late Deafened
Hard of Hearing
Cochlear Implant User
How Hearing Works
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.
Sensorineural
Hearing Loss
Sound is not
interpreted
efficiently by
inner ear. (Louder
doesn’t help!)
May be due to hair
cell/nerve damage.
May be due to
problem with
auditory nerve.
Cochlear Structure
High frequency cells
take the brunt of the
day-to-day damage;
most people lose high
frequency hearing first.
People hear the sounds,
but can’t make out the
words: "Speak up and
quit mumbling!!"
Low Frequency
speech sounds are
fewer than high
frequency.
People have
difficulty hearing
words in two
competing signals
(cocktail party
effect)
Normal Hearing
Looks Like:
Normal
Inner
&
Outer
Hair Cells
Sensorineural
Hearing Loss
Going…
Going…
GONE
Causes:
•
Congenital
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Maternal Rubella
Genetic Syndromes
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Illness and Infection
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Usher Syndrome
Waardenburg Syndrome
Measles, Meningitis
Otitis Media
Ototoxic Medication
Noise Exposure
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
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
Other Issues:
Tinnitus
• 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
Other Issues:
Meniere’s Disease
• Fluctuating:
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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
Components of a
Hearing Test
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
The Audiogram
• Volume is measured
in decibels (dB)
• The higher the line,
the better the
client’s hearing
• 90 dB loss does not
indicate the person
is 90% Deaf!
The Audiogram
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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!
Air Conduction
Tests the ability
of sound to be
processed by
the hearing
mechanism.
Shows severity
and frequency
of the
individual’s
loss.
Bone Conduction
Tests the ability
of the middle ear
to conduct sound
to the inner ear.
Used to
determine the
type of loss.
Tympanometry
Tests the
function of ear
drum and air
pressure in
middle ear
A diagnostic
tool for middle
ear problems.
Speech Audiometry
How well does person hear speech?
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Speech Reception Threshold
Speech Detection Threshold
Discrimination Score
Most Comfortable Level
Uncomfortable Level
See “What is a Hearing Aid Evaluation”
on WROCC website
Hearing Aids Simplified
Microphone—picks up sound
Amplifier—makes sound louder
Speaker—sends sound down ear canal
Bigger = more space for battery!
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
Circuit Technology
(Analog vs. Digital)
• Least Expensive
– Conventional
• Non-programmable linear (analog)
– Programmable
• Analog (with screwdriver)
• Digital (with computer)
– Digital Signal Processing
• Most Expensive
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
Hearing in Noise
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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
Two Hearing Aids Vs. One
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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
• REMEMBER—
Unemployment 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
What About Cochlear Implants?
T
The microphone sends sounds
Cochlear
implants
areeasier
designed
to brain to
to the
processor,
which
Some
sounds
are
for the
Sounds
are
transmitted
through
by-pass
the
non-functioning
codes
the
sounds
into
useful
figure
out
than
others.
Environmental
the
skin
to
the
receiver/stimulator
The
The
electrodes
codes arethen
then
stimulate
converted
the
toauditory
electrical
cochlear
hair
cells
and
provide
speech,
music,
etc.
sounds
are
less
complex
via
the
magnetic
headset.
nerve
signals
which
which
sends
activate
the
signals
the coiled
tothat
thecombinations
brain.
direct
to the auditory
of stimulation
speech
The
electrode
brain
interprets
arrayssounds.
inthese
the cochlea.
electrical signals
nerve.
into sounds.
What About
Cochlear Implants?
• Auditory Prosthesis
• Surgical procedure
• Medical clearance
required
• Replaces hearing aid
• Can restore
independence for latedeafened people
• **Destroys existing
Cochlear cells
• Does not restore
normal hearing
• Technology constantly
improving
• Does not change the
individual’s identity
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
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BB & WH
KS
SR
MT
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 normalhearing people do
• Next: Bilateral implantation?
• Note: about 45,000 people have CIs to date.
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
Resources
• “Sound and Fury”, video by Josh Aronson, 2000
• Wired for Sound, by Bev Biderman
• Cochlear Implant Forum Listserv – Email:
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To: [email protected]
From: (Your e-mail address)
Subject: (Leave it blank)
Message: Subscribe ci (your name)
Cochlear Corporation – www.cochlear.com
Advanced Bionics (Clarion) –www.advancedbionics.com
Med-El – www.med-el.com
www.hearinglosshelp.com/twohearingaids.htm
www.hearinghealth.org
Consumers Guide to Hearing Aids
www.beyondhearingaids.com:
– evaluation of consumer’s environment
• Survivor’s Manual: http://shhhor.org/survivor_manual.pdf