Motor Speech Assessment Notes

MOTOR SPEECH ASSESSMENT SLH 371 Spring 2025

Introduction to Motor Speech Disorders

  • Voice Disorders: Can be organic, functional, or psychogenic.
    • Example: Cancer in the larynx may necessitate a total laryngectomy.
  • Laryngectomy Adaptations: Required to resume voicing after a total laryngectomy.
  • Neural Pathways for Speech:
    • Brainstem to muscle: The final common pathway, the last link in the chain.
    • Basal ganglia: Inhibits and initiates articulation.
    • Premotor cortex: Involved in planning, maintenance, and learning of articulation, with output to the brainstem.
  • Motor Speech Disorders:
    • Abnormalities in the speech-motor system cause motor speech disorders.
    • Damage to specific parts of the speech-motor system results in motor speech disorders that reflect the underlying neural system involved.
    • Dysarthria: Results from dysfunction in motor execution.
    • Acquired apraxia of speech: Results from dysfunction in speech motor planning/programming.

Goals of Motor Speech Assessment

  • Describe perceptual characteristics of the individual’s speech and relevant physiologic findings.
  • Describe the speech sub-systems affected and severity of impairment in each.
  • Assess the impact of motor speech disorder on speech intelligibility and naturalness, communication efficiency and effectiveness, and participation (ASHA Practice Portal).

Cranial Nerve Examination

  • Damage to cranial nerves (CNs) can influence voice, speech, and swallowing.
  • Cranial nerve examination is a critical part of an SLP’s exam and helps with differential diagnosis.

Cranial Nerve Functions

  • V: Trigeminal
    • Type: Both (Sensory/Motor)
    • Sensory: Face & head
    • Motor: Muscles of mastication
  • VII: Facial
    • Type: Both
    • Sensory: Ear, Taste
    • Motor: Muscles of facial expression
  • IX: Glossopharyngeal
    • Type: Both
    • Sensory: Pharynx, Taste
    • Motor: Stylopharyngeus muscle
  • X: Vagus
    • Type: Both
    • Sensory, Motor, and Autonomic functions of larynx, viscera, etc.
  • XII: Hypoglossal
    • Type: Motor
    • Tongue muscles (except 1)

Respiratory-Phonatory Examination

  • Respiration provides subglottic air pressure to vibrate vocal folds; requires full, steady supply of air.
  • Phonation drives voiced phonemes; requires vocal fold (VF) tension + subglottic pressure.

Non-Speech Laryngeal Function

  • Sharp cough: Assesses VF adduction and respiratory support.
    • Inadequate VF adduction and/or respiratory support results in a weak cough.
  • Glottal coup: Doesn’t rely (as much) on adequate respiratory support.
  • Inspiratory stridor: Reveals dysfunction of VF abductors.

Sustained /a/

  • Assesses adequacy of breath support and VF adduction.
  • Inadequate breath support leads to inadequate subglottal pressure and inability to prolong /a/ for 15 seconds.
  • Incomplete VF adduction leads to excess air escape and inability to prolong /a/ for 15 seconds.
  • Latency to begin phonation.
  • Vocal quality: Harsh, Breathy, Strained-strangled, Wet.
  • Increasing loudness, vocal quality and steadiness.
  • Pitch glide, pitch range, vocal quality, steadiness.

Maximum Phonation Time Data

  • YOUNG MALES: 28.5±8.428.5 \pm 8.4
  • YOUNG FEMALES: 22.7±5.722.7 \pm 5.7
  • ELDERLY MALES: 13.8±6.313.8 \pm 6.3
  • ELDERLY FEMALES: 14.4±5.714.4 \pm 5.7

Vocal Quality

  • Harsh, breathy, strained-strangled, wet
  • Due to weakness in the phonatory/respiratory system
  • Due to problems sequencing motor movements to produce /a/

Respiratory Instrumentation

  • Respitrace
  • Spirometry: Measures lungs' airflow.

Laryngeal Instrumentation

  • Laryngeal Mirror
  • Flexible Nasoendoscopy +/- Stroboscopy
  • Rigid Endoscope +/- Stroboscopy
  • Electromyography (EMG)

Acoustic/Aerodynamic Analysis

  • Waveform and spectrum analysis
  • Intensity and spectral features
  • Formant analysis (F1, F2, F3)
  • Mel-cepstral analysis (MFCCs)

Resonance Examination

  • Resonance is the proper placement of tonality (oral or nasal) onto phonemes.
  • Requires quick velar movement throughout range of motion and sufficient muscle activity.
  • Sustained /u/ with mirror under nose to check for fogging of mirror
  • Listen for change in resonance when pinching nose
  • High-Pressure Oral Consonants:

Resonance Instrumentation

  • Nasometry
  • Nasendoscopy

Articulation Examination

  • Articulation shapes the vocal airstream into phonemes.
  • Requires articulators to perform movements with appropriate timing, direction, force, speed, and placement.

Diadochokinesis (DDK)

  • Alternating Motion Rates (AMR)
  • Sequential Motion Rates (SMR)
    • Rate
    • Steadiness/Rhythm
    • Precision
    • Range of motion

AMR Rate Data (syllables/sec)

  • /pa/: 6.3±0.76.3 \pm 0.7
  • /ta/: 6.2±0.86.2 \pm 0.8
  • /ka/: 5.0±0.85.0 \pm 0.8
  • /pataka/: 5.0±0.75.0 \pm 0.7

Articulation Instrumentation

  • Acoustic analysis
  • Pressure/force transducers (e.g., IOPI - Iowa Oral Performance Instrument)
  • EMG
  • Videofluoroscopy
  • Electromagnetic articulography

Prosody Examination

  • Prosody is the melody of speech.
  • Requires coordinated participation of respiration, phonation, resonance, and articulation

Prosodic Dimensions

  • Stress: Overall pattern, variation, lexical stress, emphatic stress.
  • Rate: Overall rate, maintenance, rushes of speech, fluctuations.
  • Phrasing: Breath support, audible inspiration, length of breath group, naturalness of pauses.
  • Loudness: Appropriateness, maintenance, variation (normal/abnormal).
  • Pitch: Steadiness, appropriateness, variation, breaks.

Prosodic Instrumentation

  • Respitrace
  • Acoustic analysis (F0 & intensity contours)

Combined System Assessments

  • Communication Effectiveness Survey: Assesses communication under several conditions
  • Dysarthria Impact Profile: Assesses psychosocial impact of dysarthria.
  • Living with Dysarthria: captures speech judgements, limitations of dysarthria and other cognitive-communication disorders, coping strategies.
  • Communication Participation Item Bank: Assesses interference with participation in a variety of communication situations.
  • Patient-Reported Outcomes.

Intelligibility and Comprehensibility

  • Intelligibility: Degree to which a listener understands the auditory signal produced by a speaker
  • Comprehensibility: Degree to which a listener understands speech based on the auditory signal + all other information that may contribute to understanding.
  • Efficiency: Rate at which intelligible or comprehensible information is conveyed.

Standardized Dysarthria Assessments

  • Frenchay Dysarthria Assessment: Assesses respiration, voice level, voice quality, voice stability, nasal resonance, articulation, rate, fluency, and prosody.
  • Bogenhausen Dysarthria Scales
  • Radboud Dysarthria Assessment (RDA)

How to Assess Intelligibility

  • Likert-scale % estimation
  • Visual-analog scale
  • Number of words correctly identified from list of words
  • Transcription, then assess for number of words/syllables correctly identified by transcribers

Apraxia Examination

  • Apraxia is the difficulty with planning/programming of motor speech movements
Assessment Tasks:
  • Diadochokinetic rates
  • Imitation of words of increasing length
  • Latency/utterance time for naming pictured multisyllabic words
  • Articulatory adequacy during repetitions of polysyllabic words

Standardized Apraxia Assessment

  • Apraxia Battery for Adults (ABA-2)

Apraxia of Speech Rating Scale

  • AOS - primary distinguishing features (no overlap with dysarthria or aphasia).
    • One or more must be present for diagnosis of AOS.
    • Distorted sound substitutions
    • Distorted sound additions (not including intrusive schwa)
    • Increased sound distortions or distorted sound substitutions with increased utterance length or increased syllable/word articulatory complexity
    • Increased sound distortions or distorted sound substitutions with increased speech rate
    • Inaccurate (off-target in place or manner) speech AMR's (alternating motion rates, as in rapid repetition of "puh puh puh")
    • Reduced words per breath group relative to maximum vowel duration
  • Distinguishing features unless dysarthria present
    • Syllable segmentation within words > 1 syllable
    • Syllable segmentation across words in phrases/sentences
    • Sound distortions
    • Slow overall speech rate
    • Lengthened vowel &/or consonant segments
    • Lengthened intersegment durations (between sounds, syllables, words, or phrases; possibly filled, including intrusive schwa)
  • Distinguishing features unless aphasia present
    • Deliberate, slowly sequenced, segmented, &/or distorted (including distorted substitutions) speech SMRS in comparison to speech AMRS
    • Audible or visible articulatory groping; speech initiation difficulty: false starts/restarts
  • Distinguishing features unless dysarthria &/or aphasia present: Sound or syllable repetitions, Sound prolongations (beyond lengthened segments)

Non-Verbal Oral Praxis Assessment

  • Assesses ability to perform oral movements on command and imitation.
  • Examples: Cough, blow, click your tongue, smack your lips.
  • Persons without AOS or aphasia should earn 29+ points.

Summary

  • To evaluate the impact of motor speech issues on communication and daily living and determine clinical recommendations, it is critical to assess each of the speech sub-systems and to also examine perceptual characteristics of speech production, physiological performance, and the context of speech production use.