Speech Intelligibility: Clinical Treatment Approaches for Children and Adults

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Speech Intelligibility Clinical Treatment
Approaches for Children and Adults

• Connie Keintz, Katherine Hustad, Jane Garcia,
  Estelle Klasner

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Roadmap of the session

• Introduction to intelligibility and related
  concepts
• Variables that influence intelligibility
• Interventions to enhance intelligibility
• Listener barriers and strategies to
  intelligibility

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Traditional view of intelligibility

• Deficit belongs to the speaker
• Identify subsystem problems
• Provide intervention to remediate subsystem
  problems
• No consideration of partner-related variables and
  their contribution to intelligibility deficits

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Multi-dimensional view of intelligibility

• Communication is dyadic
• Speaker and listener play equally important roles
• Meaning is co-constructed in real communication
  situations

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Speech Intelligibility

• The extent to which a signal, produced by a
  speaker, can be deciphered by a listener

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Measurement of Intelligibility

• Orthographic transcription
• Scaling procedures
• Percentage estimates

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Measurement of intelligibility

• Listen to the following sentences
• Write down what you hear.

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Measurement of intelligibility

• We talked about the situation.
• The idea for it was mine
• When you are through, write a report.
• There are two methods for soaking dry beans
• 26 possible words

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Clinical uses of Intelligibility measures

• Index of severity
• Index of functional limitation
• Measure of change over time
• Treatment progress
• Recovery
• Degeneration

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Limitations of intelligibility measures

• No information about underlying reasons for
  problem
• Nature of listener difficulties
• Nature of production deficits
• Intelligibility influenced by many factors
• Clinical measures are a snapshot of performance
  in a specific context
• Usually NOT a real communication situation

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Comprehensibility

• Contextual intelligibility
• The extent to which a listener can recover a
  message, produced by a speaker, when the listener
  is given contextual information that emulates
  real communication contexts.

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Measurement of Comprehensibility

• Orthographic transcription with contextual cues
• Cue communication
• We talked about the situation.
• Cue thinking
• The idea for it was mine
• Cue homework
• When you are through, write a report.
• Cue cooking
• There are two methods for soaking dry beans

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Comprehensibility vs. intelligibility

• Intelligibility measures deliberately omit
  contextual information
• Both measure employ orthographic transcription
• Both measures provide correct scores

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Listener comprehension

• The extent to which a listener is able to
  understand a spoken message
• Higher level processing
• Value of individual words comprising the message
  de-emphasized
• Gestalt of primary importance.

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Measurement of comprehension

• Answer open ended questions about the content of
  a spoken message
• Answer yes/no questions about the content of a
  message
• Re-tell the narrative (emphasis on content, not
  specific words)

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Measurement of comprehension

• Listen to the following short narrative

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Measurement of comprehension

• Answer these questions
• What is the topic of the story?
• What was the final outcome of the story?
• What may have happened beforehand to make the
  event described in the story necessary?
• Based on the outcome of the story what might
  happen next?

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Measurement of comprehension

• Target sentences produced by the speaker
• Jason needed to buy a car.
• He considered two different models.
• He did not have much money to spend.
• He bargained with a salesman for two hours.
• The final price was within his budget.
• A used jeep was what he purchased.

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Differences between measures
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Relationship between measures
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Which measure is best?

• Intelligibility, comprehensibility, and
  comprehension measures each provide different,
  yet complementary information.
• Select measures that are appropriate for your
  clinical purpose.
• To characterize the functionality of speech, use
  measures that capture information-bearing
  capability

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Connie Keintz, Ph.D. CCC-SLP

• Assistant Professor
• Communication Sciences Disorders
• Florida Atlantic University
• Boca Raton, Florida

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Variables that influence intelligibility

• Linguistic characteristics of the message
• Semantic Cohesion
• Length of Message
• Semantic Predictability
• Visual Information

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Semantic Cohesion

• Research Factors
• Key words/Cohesion higher scores
• (Drager Reichle, 2001 and Hustad Beukelman,
  2002)
• Clinical Considerations
• Keep ideas related for listener benefit
• This works in our favor in natural communication

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Length of Message

• Research Factors
• Word is harder to understand in isolation than in
  a sentence (Miller, et al, 1951, Sitler, et al,
  1983, Yorkston Beukelman, 1981)
• Clinical Considerations
• Provide context whenever possible
• Teach your speakers to present it
• Instruct your listeners to look for it

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Semantic Predictability
High versus Low Predictability
She is drinking from her _____.
cup
Bob would consider the _____.
pole

• Clinical Considerations
• High will allow listeners more information

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Visual Speech Information

• Buy Bobby a puppy.
• Here is his hand.

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Dysarthria types

• Sound different
• Appear different

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Intelligibility

• the degree to which a speakers intended message
  is recovered by a listener
• Kent, Weismer, Kent, Rosenbek (1989)

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(No Transcript)
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Measurement tools

• Rely on auditory-only information
• Visual information
• not critical
• may benefit listeners

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Model of IntelligibilityYorkston (2003)
Impairment
Presentation mode
Familiarity
Speech Signal
Listener
Transmission
Compensations
Experience
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Visual Information Research

• AV Auditory Visual
• AO Auditory Only
• Medium/Transmission is compromised in normal
  studies

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Visual information intelligibility studies

• Normal AV gt AO
• Hearing-impaired AV gt AO
• Laryngectomee AV gt AO

Dysarthria mixed results
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Speakers with dysarthria

• Intelligibility scores across moderate
• AV gt AO
• Intelligibility scores across severe
• No difference in AV/AO
• Hunter, Pring, Martin (1991)

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Speakers with dysarthria

• Intelligibility scores across speakers
• AV gt AO in 1 of 5 speakers
• Hustad Cahill (2003)

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Speakers with dysarthria

• Intelligibility scores across speakers
• AV gt AO in 3 of 8 speakers
• More benefit in more severely impaired speakers
• Keintz Bunton (2004)

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Visual Information

• Influence on intelligibility may be linked to
  severity
• More research is needed to explore
• facial movements, severity, types of
  dysarthrias

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Visual Information

• What does this mean clinically?
• Consider each patient specifically
• Evaluate with listeners having access to visual
  information
• Allow for visual information, if useful in
  communicative context
• Remember that with most speakers, it will be
  beneficial

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Visual Information

• Are there speakers who may be hindered by visual
  information?
• Moebius Syndrome
• Amyotrophic Lateral Sclerosis
• Hyperkinetic Dysarthria

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Supplemental Cues Speaker Strategies that
Augment Listener Understanding

• Jane Mertz Garcia
• Kansas State University
• Manhattan, KS

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What is speech supplementation?

• Speaker implemented strategies that augment or
  enhance natural speech
• Hand gestures while speaking
• Alphabet cues (pointing to the1st letter of each
  word while speaking)
• Topic cues (prep listeners about topic)
• Predictable messages (sentence form/semantic
  content)
• Voice output AAC devices (to supplement speech)
  or writing/drawing key points

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Simply stated

• Supplemental strategies provide clues and
  extra sources of information that help
  listeners understand less intelligible speech

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Supplemental strategies

• Take advantage of the interactive and dynamic
  aspect of speaker-listener interactions
• Recognize that listeners naturally apply multiple
  sources of shared information in a difficult
  listening situation
• Provide listeners additional content information
  to help understand less intelligible speech
• ResultSpeakers with dysarthria are more
  effective communicators as messages are
  understand with greater accuracy.

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Candidates for Supplementation

• Severity of intelligibility impairment
• moderate to severe/profound reductions
• speaker will have difficulty communicating with
  behavioral interventions alone
• Current speaking skills overall motor abilities
• strategies may interact in positive or negative
  ways with current communication abilities
• Type of dysarthria (should be less important)

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Hand gestures (Gesticulations)

• The natural hand movements people use when
  speaking
• By definitionthey occur while talking are
  idiosyncratic in nature
• There are various forms of gesticulations that
  vary in information content and function
• Iconicillustrates some aspect of the spoken
  message (concrete representation of action,
  event, or object)
• Beatadds emphasis accentuates speech (no
  content information)

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Application as a supplement strategy(particularly
iconic hand gestures)

• Maximize a natural aspect of communication (hand
  gestures naturally occur while speaking)
• Unaided technique (nothing required external to
  the body)
• Add meaning and illustrate the content of a
  spoken message
• Provide listeners 2 signals (nonverbal spoken)
  about the same underlying message

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AudioVisual Listening Condition (Garcia
Dagenais, 1998)

Key point Intelligibility scores improved by 20
and 35 with the addition of hand gestures while
talking
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Case study illustration

• 12 year-old-male (approximately 3 months TPO)
• Cranial nerve damage following removal of
  brainstem tumor
• Speaking pattern--Flaccid dysarthria (hypernasal
  resonance imprecise articulation)
• 27 Sentence Intelligibility Test (142 wpm)
• Strengths cognitive language abilities
• UE control for gesturing motivation family
  support

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Treatment Approach

• Goal-- Increase use of content (iconic) gestures
• Take what you do naturally, but do it more
  often
• Phases of therapy-- controlled to less
  structured speaking tasks
• Add gestures in sentences conveying similar
  language concepts (actions, descriptive words,
  pointing gestures)
• Apply gestures to random sentences
• Increase gestures in controlled discourse tasks
  

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Study Impact of Hand Gestures(Garcia, Crowe,
Redler Hustad, 2004)

• Natural speaking situation (self-generated
  monologues and gestures)
• Monologuessimilar in length, speaking rate, and
  amount of iconic gesturing
• Impact of gesturing
• Words identified correctly (percent
  intelligibility)
• Message comprehension

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Methods

• Cue Conditions
• Full view (all visual cues including
  gesticulations)
• Face cues (edited to only show the speakers face
  while speaking)
• Audio-only (eliminated the video signal)
• 36 everyday listeners heard different monologues
  in each condition
• Counterbalanced (presentation order assessment
  format)

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Percent of Understanding
Natural hand gestures while speaking enhanced
intelligibility (compared to face audio only)
(p lt .05)
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Message Comprehension
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Message Comprehension
Natural hand gestures while speaking enhanced
message comprehension (p lt .05)
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Specific Questions

• Full Face cues exceeded auditory only
• Main theme, Add comment, Actions were superior in
  Full view vs. Face cues condition

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Alphabet supplementation

• Aided strategyspeaker points to the first
  letter of each word on an alphabet board as he or
  she says it.
• Speaker
• Decreases rate of speaking by about 70
• Provides additional time to execute motor
  movements (improve articulation)
• Listener
• 1st Letter cue narrows range of word choices
• Increased processing time for listeners
• Creates clear word boundaries

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Sample alphabet board
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Research Findings Sentences

• Consistently positive benefits for most
• Linguistic cues alone (superimposed while
  speaking) increase intelligibility by 25 (Hustad
  Beukelman, 2001)
• Reduced rate of speech alone increases
  intelligibility by 25 (Crow Enderby, 1989)
• When rate is reduced AND speakers have first
  letter information, intelligibility may be
  increased by up to 44 (Beukelman Yorkston,
  1977 Hustad, Jones, Daily, 2003)

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Application of alphabet supplementation to therapy

• Improving speaker understanding by enhancing
  listeners linguistic knowledge
• Increasing redundancy in signal
• Modifying speakers production characteristics in
  helpful ways
• Useful for resolution of communication breakdown
• Relatively easy to instruct patients in its use

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Integrating supplementation strategies

• Most individuals with dysarthria can benefit from
  having multiple communication options
• Hand gestures and alphabet supplementation are
  not mutually exclusive strategies
• In fact, some individuals benefit similarly from
  both strategies

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Hand Gestures Vs. Alphabet Cues(Hustad Garcia,
2005)

• Alphabet cues hand gestures scores were similar
  for Speaker A C
• Speaker BAlphabet cues were significantly higher
  than hand gestures

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Hand Gestures Vs. Alphabet Cues(Hustad Garcia,
2005)

• Changes in speaking rate

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Cost-Benefit Ratio Hand Gestures

• Costs
• Must have strong metacognitive abilities
• Must have adequate motor skills
• Adequate respiratory support for chunking
• Benefits
• Considered an unaided strategy nothing
  extrinsic to the body is needed for strategy
• May contribute to naturalness given adequate
  respiratory

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Cost-Benefit Ratio Alphabet Cues

• Costs
• Considered an aided strategy (you need an
  alphabet board)
• Must have functional literacy skills
• Reduces naturalness
• Benefits
• Easy to learn (compared to incorporating hand
  gestures)
• Basic motor skills for pointing to letter cues
• Rate reduction may benefit production

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Dysarthria Associated With ALS and HD Barriers
to Understanding and Strategies for Listening

• Estelle R. Klasner, PhD, CCC-SLP
• New Mexico State University
• ASHA, 2006

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Current Understanding of Speech Intelligibility

• Speech intelligibility is an outcome measure in
  dysarthria
• Speech intelligibility is reduced in all types of
  dysarthria
• Research focus has primarily been on speaker
• Listener role is beginning to be studied

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Questions

• Do barriers to intelligibility vary as a function
  of dysarthria group, ALS versus HD?
• Do strategies for listening vary as a function of
  dysarthria group, ALS versus HD?

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Study Overview
Subjects
Task
Components
Individuals with Dysarthria Read/
Record SIT
sentences (n10)

varying length

Judges (n65)
Transcribe SIT
Focus groups (n 4x12)
LTCD
Scales
Content Analysis
Pilot Listeners (n6)
LTCR Revised Scales
Everyday Listeners (n 65) LTC R
Endorsement Patterns
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Speech Sample Populations

• Five individuals with amyotrophic lateral
  sclerosis (ALS)
• Age range 45-68 years
• Disease duration 3-8 years
• Five individuals with Huntington Disease (HD)
• Age range 32-46 years
• Disease duration 4-16 years

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Focus Group Task-LTCD

• L - Listen to the sentence.
• T - Transcribe what was heard.
• C - Compare transcription to actual sentence
• D - Discuss barriers and strategies.

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ALS Sample

• You burned your fingers fishing out the toast
  when it didnt pop up.
• Sample Transcription Your fingers picked up the
  _____when it bopped the top.
• Question If you didnt understand the
  sentence, what made this difficult to understand?

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HD Sample

• Being close to people is important to me.
• Sample Transcription ______ to people is
  pertinent.
• Question If you didnt understand the
  sentence, what made this difficult to understand?

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Domains of Barriers and Strategies

• Barriers n24
• Segmental n6
• Suprasegmental n6
• Linguistic n6
• Cognitive n6

• Strategies n24
• Segmental n6
• Suprasegmental n6
• Linguistic n6
• Cognitive n6

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Segmental Barriers

• Any remarks that relate to the phonemes, or
  phonetic structure of the words used in the
  sentence
• Consonants were missing
• Vowels were indistinct
• I heard different sounds than the person actually
  said

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Suprasegmental Barriers

• Any remarks that related to the rate or rhythm of
  the sentence, i.e., the prosodic features of the
  sentence.
• Pauses occurred in the wrong places
• The rate was variable
• Pauses were too short

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Linguistic Barriers

• Any comments that related to the semantic or
  syntactic structure of the sentence
• I couldnt predict the rest of the sentence based
  on the words I understood
• The sentence didnt mean what I expected based on
  the words I understood
• I couldnt understand the sentence without
  context

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Cognitive Barriers

• Any remarks that related to the thinking process
  or experience that the listeners described when
  they heard the sentence
• I got distracted by the way the speech sounded
• It was hard to listen to this sentence
• I got tired listening to the sentence

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Segmental Strategies

• Any strategy that related to the phonemes and/or
  phonetic structure of the sentence
• I listened to the sounds without any attention to
  context
• I tried to put the sounds together to make words
• I pieced the syllables together to make words

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Suprasegmental Strategies

• Any strategy related to the prosodic features of
  the sentence
• I tried to break up strings of sounds into
  meaningful words
• A slow rate helped me understand difficult words
• I depended on breaks between words to understand
  the sentence

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Linguistic Strategies

• Any strategy related to the meaning or grammar of
  the sentence
• I used context to fill in the words I didnt
  understand
• I tried to predict the rest of the sentence based
  on the words I understood
• I made sense of unclear words from the context of
  the sentence

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Cognitive Strategies

• Any strategy that related to the cognitive
  experience of the listener
• I had to be prepared to hear distorted speech
• I had to concentrate on understanding the
  sentence
• I had to completely attend to the sentence to
  understand it

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Scale Administration-LTCR

• L - Listen to the sentence.
• T - Transcribe what was heard.
• C - Compare transcription to actual sentence.
• R - Rate items on Barriers/Strategies scales

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Scale Example
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Barrier Scale Categories
Mean Scale Scores



Segmental
Suprasegmental
Linguistic
Cognitive
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Discussion-Barriers

• Barrier findings for both dysarthria types are
  consistent with descriptions of Darley, Aronson
  and Brown (1975).
• Listeners rely on bottom-up information.
• Listeners also rely on top-down information,
  particularly when speech signal is compromised.
• Higher level of barriers endorsed for ALS.

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Strategy Scale Categories
Mean Scale Responses
Segmental
Suprasegmental
Linguistic
Cognitive
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Discussion-Strategies

• Strategies were highly endorsed for both types of
  dysarthria.
• High dependence on cognitive strategies.

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Clinical Application

• Result stronger endorsement of segmental,
  linguistic and cognitive barriers for ALS vs. HD
• Clinically Some aspects of treatment may be
• specific to dysarthria type.
• -Listeners may benefit from training that
  addresses the specific strengths and weakness of
  a dysarthria type.
• -topic boards for ALS
• -pacing strategies for HD

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Clinical Applications

• Result Strategies were highly endorsed for both
  types of dysarthria.
• Clinically Listeners are actively involved in
  understanding dysarthric speech
• -train listeners to use strategies effectively
• -focus treatment on the speaker listener
  interaction, i.e., train speakers to provide cues
  that allow listeners to implement strategies

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Clinical Applications

• Result Segmental, suprasegmental and cognitive
  strategies highly endorsed for ALS, while
  segmental, suprasegmental and linguistic
  strategies were highly endorsed for HD
• Clinically Both bottom-up and top-down
  strategies are important in understanding
  dysarthric speech.
• -listeners could be trained to use strategies
  that are
• reflective of the barriers in a particular type
  of dysarthria

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Follow-up Study

• Do listeners who receive high intelligibility
  scores differ in their selection of barriers and
  strategies from listeners who receive low
  intelligibility scores?

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ALS Barrier Responses
Mean Scale Responses
Segmental
Suprasegmental
Linguistic
Cognitive
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Barriers-ALS

• High group differed in their endorsement of
  barriers in ALS dysarthria from the Low group
• Significant differences between the two groups
  were found for suprasegmental and cognitive
  categories.

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HD Barrier Responses
Mean Scale Responses
Segmental
Suprasegmental
Linguistic
Cognitive
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Barriers-HD

• High group differed in their endorsement of
  barriers in HD dysarthria from the Low group
• Significant differences (plt.005) were found
  between the two groups for all of the categories,
  with the Low group endorsing barriers at a higher
  level than the High group.

98
ALS Strategy Responses
Mean Scale Score
Segmental
Suprasegmental
Linguistic
Cognitive
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Strategies-ALS

• Differences exist between High and Low groups in
  strategy endorsement patterns for ALS dysarthria.
  
• High group endorsed a significantly higher level
  of cognitive strategies than the Low group

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HD Strategy Responses
Mean Scale Responses
Segmental
Suprasegmental
Linguistic
Cognitive
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Strategies-HD

• Both High and Low Groups endorsed high levels of
  strategies
• High group endorsed a significantly higher level
  of linguistic strategies

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Discussion-ALS

• High Group differed from Low Group
• High Group increased cognitive barriers and
  strategies
• Increased cognitive processing has been observed
  in listeners as they adjust to differences (e.g.,
  accents) in normal speech production (Hazon,
  Markham, 2001)

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Discussion-HD

• High Group differed from low group
• High Group decreased barriers and strategies-more
  linguistic strategies
• Islands of intelligibility may have allowed for
  better prediction by listeners

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Contact Information

• Connie Keintz (ckeintz_at_fau.edu)
• Katherine Hustad (Kchustad_at_wisc.edu)
• Jane Mertz Garcia (jgarcia_at_humec_at_ksu.edu)
• Estelle Klasner (enk_at_nmsu.edu)