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TOPIC
4
BEHAVIORAL ASSESSMENT
MEASURES
The Audiometer

Types
Clinical
 Screening

The Audiometer

Components




Pure tone oscillator
Attenuator
Interrupter switch
Output transducer
o
Headphones
•
•
o
Bone conduction vibrators
•
•
o
Supra-aural
Insert
Forehead
Mastoid
Loudspeakers
Audiometer Components
Pure Tone Audiometry
“The aim of pure tone audiometry is to
establish hearing threshold sensitivity
across the range of audible frequencies
important for communication”
The Audiogram
Air Conduction vs Bone
Conduction Testing
Air conduction tests
the entire auditory
system. Bone
conduction
bypasses the
conductive
mechanism, so it
tests only the inner
ear.
Audiometric Symbols





Unmasked air conduction
 Left ear
 Right ear
Unmasked bone conduction
 Left side
 Right side
Masked air conduction
 Left ear
 Right ear
Masked bone conduction
 Left ear
 Right ear
No response
What the Audiogram Says
About the Impairment
Within normal limits
Mild
Moderate
Severe
Profound/deaf
What the Audiogram Says
About the Impairment
The configuration of
the hearing loss
 Flat
 Rising
 Sloping
What the Audiogram Says
About the Impairment



The degree of hearing loss
The configuration of the hearing loss
The type of hearing loss
Conductive
 Sensorineural
 Mixed

Establishing a Pure Tone
Audiogram
o
o
o
o
Establish which is the better ear and
test first
Start air conduction testing at 1000 Hz
Begin at 30 dB HL. If there is no
response, increase intensity in 20 dB
steps until you see a response
Follow the “down in 10, up in 5” rule
ASHA Procedure
Hypothetical threshold search for a listener whose
threshold is 35 dB HL. A + indicates the listener
heard the presentation, and a - shows the listener
didn’t hear the tone. Notice that the hearing level of a
trial is raised by 5 dB following a - and is lowered by
10 dB following a +.
Establishing a Pure Tone
Audiogram
o
o
o
o
After several crossings of the same
intensity, pick threshold as an intensity
where 50% of the time the listener responds
correctly
Move to 2000 Hz, 3000 Hz, 4000 Hz, and
8000 Hz (as a minimum)
Pick up the low frequency (500 and 250 Hz)
tones
Repeat for the other ear
Speech Audiometry
Uses:
 Sensitivity for speech







Speech awareness threshold
Speech reception threshold
Pure tone cross check
Speech recognition
Differential diagnosis
Central auditory processing
Estimate of communicative function
Speech Audiometry
Materials
 Types
Nonsense syllables
 Monosyllabic words
 Spondaic words
 Sentence tests

Speech Audiometry
Relationship of redundancy of informational content and
sensitivity to the effects of hearing loss on three types
of speech recognition materials
Speech Audiometry


Intrinsic redundancy
Extrinsic redundancy
 Frequency--low
pass filtering
 Time--time compression
 Intensity--high presentation levels
 Competition--speech in noise
 Binaural--dichotic measures
Speech Audiometry
Relationship of intrinsic and extrinsic
redundancy to speech recognition ability in
normal listeners
Speech Audiometry
Clinical Methods

Speech thresholds

Speech Reception threshold
o
o
o
o
o
Start audible
Present four spondees
Calculate percent-correct response
Follow down in 10, up in 5 rule
Stop at an intensity that provides 50%
Speech Audiometry
Clinical Methods

Speech thresholds
 Speech
Reception threshold
 Speech Awareness threshold

Word recognition testing
Word Recognition Testing
Things to consider:
 Materials
 Goals?
 Amount
of extrinsic redundancy you need?
 Language level?
 Other special needs or considerations?
Word Recognition Testing
Things to consider:
 Materials
 Presentation
Monaural?
 Binaural?
 Headphones?
 Sound field?

Word Recognition Testing
Things to consider:
 Materials
 Presentation
 Presentation Level
 Maximal
ability
 Normal conversational level
Speech Audiometry
Interpreting speech discrimination results. Typical
results based on disorder site
Other Behavioral Measures
Uses:
 To determine a functional or exaggerated
hearing loss
 To provide additional information necessary
to fit amplification
 To determine the presence of recruitment and
adaptation
 To determine some measure of binaural
integrity