Audibility
&
Speech
Recognition
Chapter 6
Perry C. Hanavan, Au.D.
Speech Test Applications
 obtain information for counseling
 illustrate benefits of visual cues
 determine hearing aid candidacy
– or determine candidacy for CI or ALDs
 predict hearing aid benefit
 determine when binaural aids might NOT be appropriate
– 80%, AD and 20% AS
 determine amplification characteristics and features
– whether high frequency beneficial
 demonstrate advantage of special hearing aid features
 demonstrate aided performance is better than undaided
 determine whether cognitive or APD exists
– older person may have cognitive problems, anyone may have APD
 demonstrate that understanding of speech is impaired
Audiologic Evaluation
Information helpful to providing AR
Audibility
Dynamic Range
Frequency Resolution
Temporal Resolution
Audiologic Evaluation
Critical consideration in helping to plan AR:
Time of Onset of loss
Degree of Loss
Etiology
Type of Loss
And wealth of other factors
Audiologic Evaluation
Observations
Interviews
Questionnaires
Otoscopic examination
Pure tone results
Speech recognition
Immittance
OAE
Electrophysiologic (ECochG, ABR, MLR, LR, etc.)
Pure Tone Results
Degree of loss
– normal, minimal, mild, moderate, moderately
severe, severe, profound
Type of loss
– conductive
– sensorineural
– mixed
Tactile
Only
SNR
Many
Items
Stimulus
Familiarity
Equivalent
Lists
Audition
Plus
Vision
Stimulus
Units
Distance/
Intensity
Learning
Effects
Stimulus
Context
Stimulus
Mode
Stimulus
Elements
WithinSubject
Statistical
Procedure
Audition
Only
Audition
Plus
Tactile
Vision
Only
Open
Set
Speech
Test
Factors
Clinical
Significance
Auditory
Skill
Response
Format
Closed
Set
Paired
t-statistic
Stimulus
Format
Listener
Variables
Cognitive
Ability
Communication
Mode
Test-Restest
Variability
Linguistic
Ability
Hearing
Loss
Live
Synthesized
Speech
Test
Reliability
Test
Conditions
Altered
Speech
Recorded
Stimulus Mode
Tactile
Only
auditory alone
vision alone
Audition
Plus
Vision
tactile alone
auditory and vision
auditory and tactile
tactile and vision
auditory, vision and tactile
Audition
Only
Audition
Plus
Tactile
Vision
Only
Auditory Alone
phoneme, syllable, word, phrase, sentence
open, closed set
high, low context cues
quiet, noise – signal to noise ratio (SNR)
recorded, live
Auditory Plus Vision
Speechreading enhancement
– speechreading enhancement
– speechreading enhancement ratio
• vision only / auditory plus vision = SE
– Children –Craig Sentence and Craig Words and CHIVE
– Adults –Iowa Sentence Test and CUNY Sentences
– Erber (vision and hearing assessment)
Auditory Plus Visual Information
Sumby and Pollack (1954) demonstrated
that the addition of visual speech
information could significantly improve
speech perception performance and that the
importance of visual speech information
increased as the listening situation became
more difficult.
Auditory Plus Vision
Tye-Murray
– CHIVE (adult)
– CAVET (children)
– Audition plus vision
– Vision only
– Audition alone
Eber
– Sent-Ident
Speechreading Enhancement/
Visual Enhancement
 Benefit from adding a visual signal to an auditory signal
 Refers to the benefit obtained from seeing and hearing a
speaker compared with auditory alone
– Difference or ratio between speech recognition performance in an
vision-only condition and an audition plus-vision condition
– Difference Formula (AV-V)
– Normalized Score Formula (AV-V/100-V)
 Patient A (V score=50% AV score = 75%)
– 75-50=25% enhancement (difference score)
– (75-50)/(100-50)=50% (normalized difference score)
 Patient B (V score = 10% AV score = 55%)
– 55-10=45% visual enhancement
– (55-10)/(100-10)=50% (normalized difference score)
Auditory Enhancement
Benefit from adding an auditory signal to a visual
only signal
Difference Formula (AV-A)
Normalized Score Formula (AV-A/100-A)
Patient A (A score=50% AV score = 75%)
– 75-50=25% enhancement (difference score)
– (75-50)/(100-50)=50% (normalized difference score)
Patient B (A score = 10% AV score = 55%)
– 55-10=45% auditory enhancement
– (55-10)/(100-10)=50% (normalized difference score)
Integration Enhancement
Measure of ability to integrate auditory and
visual information
AV-[100-(100-A)+(100-V)]/100-[100(100-V)+(100-A)]
THE AUDITORY SANDWICH
Visual cues:
• lip-reading
• printed word
• cued speech
• signs
HEAR
SEE - SAY
HEAR-UNDERSTAND
First, listen.
Then, if need be,
watch or say it.
Then, listen again
(no visual cues)
Always put it back into hearing!
Back to “choices”
Auditory
-Verbal
Auditory
Cued
-Oral
Speech
AUDITORY
Total
Communication
Language
Communication
Cognition
ASL
VISUAL
Choices reframed
Fully
Auditory
Mostly
Auditory
Mostly
Visual
Fully
Visual
Communicator
Communicator
Communicator
Communicator
A
Av AV VA
V
Flexibility is essential
Fully
Auditory
Mostly
Auditory
Mostly
Visual
Fully
Visual
Communicator
Communicator
Communicator
Communicator
A
Av AV VA
V
Stimulus Elements
SNR
Units: phoneme, syllable, word,
phrase, sentence, non-sense
Distance/
stimuli
Intensity
Proximity: distant, near
Intensity: soft, comfortable, loud
Context: high, low context cues,
SNR: quiet, background sounds-signal to noise ratio
Familiarity: high, low familiarity
with material, nonsense material
Stimulus
Familiarity
Stimulus
Units
Stimulus
Context
Learning Effects
Learning effect: familiarity with
items, procedures…not change in
ability
– Repeated Frame Test
– Cinderella-Brahman Speech
Recognition Test
Equivalent lists: lists that contain
items that are presumed to be
equally difficult to recognize
– PB, sentences
– Repeated Frame Sentences Test
Numerous stimuli
– Full lists rather than half lists
Many
Items
Equivalent
Lists
Stimulus Items
Live vs. Recorded
–
–
–
–
–
Voicing frequency
Intonation
Speech rate
Clarity of articulation
Physical characteristics
Synthesized speech
Altered speech
– Time-compressed
– Expanded
– Filtered
Live
Synthesized
Speech
Altered
Speech
Recorded
Significance
Clinical significance
When a small change in performance
is clinically significant
When comparison between two test
results is clinically significant
Statistical design
Paired t-statistic
Within subject statistical procedure
WithinSubject
Statistical
Procedure
Paired
t-statistic
Significant
Difference
for NU-6 recorded
speech tests
Listener Variables
Degree of hearing loss
Cognitive abilities
– Thinking, reasoning,
remembering, imagining, or
learning words
Linguistic abilities
– Knowledge of language
Communication mode used
Multicultural
Cognitive
Ability
Communication
Mode
Linguistic
Ability
Hearing
Loss
Test Reliability
 Test reliability: the degree to which
a single test score approximates the
true score
 Test-retest variability: measure of
consistency from one test
presentation to the next
 Test conditions: Variables affecting
test-retest variability:
– mode of presentation—live vs recorded
– location—test booth vs classroom
– talker—familiar vs unfamiliar, male vs
female
– number times item repeated—once,
twice, etc. leads to better performance
Test
Reliability
Test
Conditions
Response Format
Closed or limited set
Open set
Auditory skill
–
–
–
–
Detection
Discrimination
Identification
Comprehension
Open
Set
Auditory
Skill
Closed
Set
Acclimatization
and
Brain Reorganization
Plasticity
Physiological changes in the
CNS (and PNS – auditory
nerve) that occurs from sensory
experiences
– Brain’s ability to reorganize
space
– Benefit from HA, CI, HATs may
need to be measured at later date
– Brain may continue to acclimate
for several years following HA,
CI, HAT, therapy
Making Connections
A child is born with
over 100 billion
neurons or brain cells.
These neurons form
connections, called
synapses, which make
up the wiring of the
brain.
Brain Development
 EARLY EXPERIENCES At
age eight months an infant may
have 1,000 trillion synapses.
 By age 10 the number of
synapses decrease to about 500
trillion.
 The final number of synapses is
largely determined by a child's
early experiences, which can
increase or decrease the number
of synapses by as much as 25
percent.
Brain Development
 "USE IT OR LOSE IT!" The
brain operates on a "use it or lose
it" principle: only those
connections and pathways that are
frequently activated are retained.
 Other connections that are not
consistently used will be pruned
or discarded so the active
connections can become stronger.
Brain Development
 DEFINING LANGUAGE SKILLS
When an infant is three months old, his
brain can distinguish several hundred
different spoken sounds.
 Over the next several months, his brain
will organize itself more efficiently so
that it only recognizes those sounds that
are part of the language he regularly
hears.
 During early childhood, the brain
retains the ability to relearn sounds it
has discarded, so young children
typically learn new languages easily and
without an accent.
Dendrites
Dendrites are thin, branching
fibers lined with receptors at
which the dendrite receives
information from other
neurons.
The greater the surface area,
the greater the amount of
information.
Some dendrites are covered
with spines which greatly
increase its surface area.
Plasticity, Adaptation, Acclimatization
Many researchers think that training techniques
sometimes can help those with the reading
disability, dyslexia, because they modify brain
networks. The images above hint that this is the
case. The top images show the brain activity (litup areas) of a 10 year-old boy while he
completes a task that requires the ability to
identify the sounds of words. His reading level
equaled that of an eight-year-old child. The
bottom images show his brain activity while he
completes the same task after receiving eight
weeks of a type of special training. Following
the intervention training, his reading level
increased by three years and the images
indicate that his brain activity changed as
well. Researchers are conducting a very large,
ongoing study to confirm this one example.
Auditory Acclimatization
Back in the 1940s, wideband high-fidelity phonograph consoles were
just becoming available. Because of his interest in high-quality audio,
Harvey Fletcher bought one for his home. Harvey enjoyed listening to
this new high-fidelity system, but unfortunately, the enjoyment was not
shared by his wife. After listening to a an old 78 rpm record, with the
surface noise made particularly prominent by the extended bandwidth
of this new high-fidelity system, she said: "That sounds awful. I don't
really like having that screechy sound in my home."
Always the creative thinker, the next day, when his wife was out of the
house, Harvey went into the living room and soldered twenty 1 uF
capacitors across the loudspeaker terminals, rolling off the high
frequencies. (Remember that amplifiers were high impedance back
then, so the trick worked.) That evening, when the music played, his
wife was now happy.
One night each week, while his wife was sleeping, Harvey would sneak
downstairs and clip one capacitor. After twenty weeks, when the music
played, they were both happy.
Acclimatization
Adapting to a new environment (in this case, auditory) or as
defined by Darwin, the process of inuring to a new climate,
or the state of being so inured. This seems to be a reasonable
term, as it also is used to describe how the human body
acclimates to temperature, altitude, and other environmental
conditions. From an auditory standpoint, Gatehouse was one
of the first to use the term acclimatization, explaining the
speech processing capabilities of a group of people aided
monaurally. In later research Gatehouse used the term
acclimatization to describe an improvement in speech
recognition over time. Today, the term is used widely to
explain adaptation to hearing aid use in general, and is not
limited to the Gatehouse definition.
Adaptation
The process of adapting to something,
such as environmental conditions (in this
case, auditory); the responsive adjustment of
a sense organ. This too is a reasonable term,
as it has long been used in reference to the
eye—e.g., adaptation to varying light
conditions.
Sensory Reorganization
When nerve stimulation
changes, as with amputation, the
brain reorganizes. In one theory,
signals from a finger and thumb
of an uninjured person travel
independently to separate
regions in the brain's thalamus
(left). After amputation,
however, neurons that formerly
responded to signals from the
finger respond to signals from
the thumb (right).
Auditory Reorganization/Plasticity
Cochlear dead
regions
Brain
reorganization
will occur
with damage
to regions of
the cochlea
Speech Recognition Tests
WIPI
Word Intelligibility by
Picture Identification
(WIPI)
closed-set picture-pointing
(six pictures per plate)
appropriate for children
whose language age is
between 5 and 10-11
comprised of four 25monosyllabic word lists
contains 26 color plates
(one for practice), six
pictures per page. (A, V,
A-V)
NU-CHIPS
NORTHWESTERN UNIVERSITY-CHILDREN’S PERCEPTION OF SPEECH (NUCHIPS)
closed set picture pointing word recognition test
children whose language age is as low as three
50 words familiar to three-year-old children in
four randomizations
includes two picture books with 50 monochrome
plates, four pictures per plate. Book A is used for
forms A & B, book B for C & D.
There are two recordings, one male and one
female talker.
MAC
The Minimal Auditory Capabilities (MAC) (2nd
Edition) battery specifically targeted to CI patient
Consists of a series of tasks which are graded in
difficulty
Most of the MAC battery sub-tests assume patient’s
hearing loss has occurred post-lingual, but can be
employed as a means of evaluating the hearing abilities
of persons for whom traditional speech materials are
too difficult
Second edition has been standardized.
The recorded materials include gross sound
identification, inflection detection, contrast detection,
accent discrimination, and word identification
14 sub-tests, 13 audio and one video
SERT
SOUND EFFECTS RECOGNITION TEST
(SERT) developed for those instances where
conventional word recognition measures are not
appropriate, such as when language limitations due
to hearing impairment
Certain children who are unable to recognize even
simple speech can perceive correctly environmental
sounds to which they are exposed in their daily
lives
Under these circumstances, the SERT can provide
valuable information about the integrity of the
auditory system.
Closed set, picture-pointing tasks
10 sounds plus a practice sound
CID Every Day Sentences
EVERYDAY SPEECH
10 sets of 10 sentences each with 50
"target" words in each set for word
recognition assessment under contextual
conditions
Can be employed in auditory training
Sentences vary in length and are spoken
with minimal inflection
Normative data on recording lacking
BKB Sentences
Bench, Koval, & Bamford (BKB)
 Open set sentences
 Appropriate for linguistic abilities of most 8-15 years of
age with hearing loss
 Lists of 16 simple sentences, including 50 key words were
devised to include vocabulary, grammar and sentence
length for 8-15 year olds
 The sentences are presented in an open-set format and the
child imitates as much of the sentence as possible.
Responses are recorded word-for-word and scored by
percent of key words correctly repeated.
NU-6
NORTHWESTERN UNIVERSITY
AUDITORY TEST NUMBER SIX (NU-6)
Phonetically balanced CNC monosyllabic
open set word recognition test
Four lists of 50 words each recorded in four
randomizations
Talker has a General American dialect
Standardized
Auditory Numbers Test
ANT
Test helps identify tactile from auditory
listeners
Word closed set recognition auditory alone
test
Appropriate for 3-8 year old children with
severe to profound hearing loss
Simple auditory alone test to measure
ability to perceive simple auditory cues
– (Erber, 1980)
Iowa Consonant Confusion Test
Closed set consonant (phoneme) recognition test
test can also be analyzed in terms of the listener's
ability to identify phonetic features:
– Chance performance for consonant voicing, manner, and
place of articulation identification is 50%, 33%, and 20%
respectively
– Example: Mr. S achieved a total score of 79% correct,
96% on voicing, 94% on manner, and 85% on place
10 consonants presented 12 times in VCV context
–
–
–
–
p, t, k, b, d, g, v, z, n, m
Presentation examples: aba, ada, aga, etc
Each consonant presented 12 times in random order
Presented with carrier phrase “The next word is”
• (Tyler et al, 1983)
S
t
i
m
i
l
u
s
p
t
k
b
d
g
v
z
n
m
p
0
0
0
1
1
1
1
1
0
0
t
2
3
1
1
0
0
2
2
1
0
k
6
2
3
2
3
5
1
0
0
0
Response
b d g v
2 1 0 0
1 1 0 1
0 0 3 1
2 0 3 1
2 0 0 1
0 2 0 0
0 3 0 2
2 0 0 3
0 0 0 0
0 0 0 0
z
0
4
2
0
2
0
1
0
0
0
n
0
0
1
1
3
0
2
2
4
4
m
1
0
1
1
0
4
0
2
7
8
Example
of Iowa
Consonant
Confusion
Test
(example:
auditory
alone)
Children’s Auditory Test
CAT
Auditory alone limited set test assessing
ability to perceive stress patterns and word
recognition
Consists of 12 words
– Monosyllabic words
– Trochees
– Spondees
IMSPAC
Imitative tests of Speech Pattern Contrast
Perception
Developed by Arthur Boothroyd
Syllable level, 4 lists randomized
Choose odd one of 3 (forced choice)
Pointing, button-press or verbal response
Age 7 years and up
AB Short Word List
Isophonemic Word List
Developed in 1968 by Arthur Boothroyd
Speech recognition open set test
Each list consists of ten words, and each word is
constructed as consonant - vowel – consonant
30 phonemes, 10 vowels and 20 consonants
present in each list
CNC words
Score is based on the phonemes correct out of 30
Larsen Recorded Test
Auditory word discrimination test
Pairs of phonemes in words
– few vs. chew
– bill vs. mill
– nice vs. vice
Lists represent an attempt to present the phone in
the initial, medial and final position of a word
Limited choice—select one of two words by
drawing line through printed word heard
CAVET
Children’s Audiovisual Enhancement Test
 Assesses speechreading enhancement in children within
the vocabulary level of 7-9 year olds with profound
prelingual hearing loss
 Designed to minimize ceiling and floor effects, eliminate
syntactic factors, and minimize semantic factors
 3 lists of 20 words each with half of words easy to
recognize in a vision-only condition and half are less likely
to be recognized in each list but presented in random order
 Each list is designated for auditory alone, visual alone, or
auditory-visual only mode
 Test available in CD-ROM and VHS format
– (Tye-Murray & Geers, 2002)
CUNY Sentences Test
The City University of New York (CUNY)
Topic Related Sentence Sets consist of 25
equivalent sets of 12 sentences of varying length
Each sentence is related to one of 12 topics
Open set sentence recognition test
Listener is presented with sentences in three
listening conditions: A, V and AV
The test is scored with the total number of words
correctly identified
(Boothroyd, Hannin, & Hnath, 1985)
Lexical Neighborhood Test (LNT)
Lexical neighbors--words that sound similar to a target item.
Often defined as words that differ by a single phoneme from
target word
Open-set test that requires child to imitate stimulus words
immediately after they are presented
Each list consists of 50 monosyllabic words, 25 of which
are high-frequency words with few lexical neighbors (easy)
and 25 of which are lower frequency words with many
lexical neighbors (hard)
Words were selected to be familiar to children with limited
vocabularies.
– Easy Words: juice, good, drive, time, hard, gray, foot, orange, count
– Hard Words: thumb, pie, wet, fight, toe, cut, pink, hi, song, fun, use, mine,
 Alternate version of test, the Multisyllabic Lexical Neighborhood
Test (MLNT) consists of 50 words with two to three syllables.
– (Kirk, Pisoni, & Osberger, 1995)
QuickSIN
 Provides a one-minute estimate of SNR loss for adults
 A quick method to quantify patient’s ability to hear in noise
 Can determine if extended high frequency emphasis improves or
degrades understanding of speech in noise
 Assist in choosing appropriate amplification and/or other hearing
assistance technologies
 Demonstrates directional microphones may improve speech
intelligibility in noise
 Open set test recognition test
 Consists of list of six sentences with five key words per sentence
presented in four-talker babble noise.
 Sentences are presented at pre-recorded signal-to-noise ratios which
decrease in 5dB steps from 25 (very easy) to 0 (extremely difficult).
 The SNR's used are 25, 20, 15, 10, 5, 0, encompassing normal to
severely impaired performance in noise.
BKB - SIN
Similar to Quick-SIN but can be utilize
with children
Sentence recognition using BKB sentence
material
Open set sentence recognition test
BKB SIN test
Test score sheets
HINT
 The HINT is a prerecorded test that measures
sentence speech recognition abilities in quiet or in
noise accurately, reliably and efficiently
 The HINT demonstrated the substantial role that
binaural, directional hearing plays in a normal hearing
individual's ability to communicate in noise
 Any degree of hearing impairment, therefore, reduces
the benefits of directional hearing in noise and
increases communication inadequacy
 Used to evaluate functional hearing capabilities of HI
users, CI users and those in listening-critical jobs
 Copyrighted by the House Institute and is available
for purchase on a compact disc recording to hearing
clinics and research laboratories nationwide.
 A children's version of the HINT is also available
DICHOTIC SENTENCE
IDENTIFICATION (DSI)
 Developed in an attempt to conceive a dichotic listening task that
would be only minimally affected by peripheral hearing loss
 Sentences selected from the Synthetic Sentence Identification (SSI)
test presented dichotically
 Onsets and offsets of the sentences are aligned with an accuracy of
100 microseconds.
 Developers claim DSI less susceptible to hearing loss than SSW
test
 Viable test of central auditory function with hearing loss
 Test applicable for auditory assessment of impaired ears through
pure tone averages (PTAs) up to 50 dB
 2 sets of 30 pairs of sentences (closed set identification test)
 Normative data are available
Ling-6
Phoneme level detection and recognition
test
m, s, sh, e, a, u
Procedure
Detection and identification of phonemes
Further Auditory Evaluations
Mark C. Flynn—Evaluation of Individuals
with hearing loss
Assignment
If you accept the challenge, assign each test
discussed in this section on the following
grid, thus,
Be able to correctly indicate on the
following template, each of the auditory
tests discussed earlier
Speech Paradigm
Detection
Non-Speech
Sounds
Phonemes
Syllables
Suprasegmentals
Words
Phrases
Sentences
Connected
Speech
Discrimination
Recognition
Comprehension
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Audibility & Speech Recognition