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Chapter 9 Breakdowns in Production of Vowels and Consonants. Perry C. Hanavan, Au.D. Source Filter Theory and Problems in Speech Production. Source-filter a way of conceptualizing problems of speech production Dysarthria—neurologic disorder with weak speech musculature
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Chapter 9Breakdowns in Production of Vowels and Consonants Perry C. Hanavan, Au.D.
Source Filter Theory and Problems in Speech Production • Source-filter a way of conceptualizing problems of speech production • Dysarthria—neurologic disorder with weak speech musculature • Hearing loss—difficulty with relationship with acoustic input and speech production • Phonological disorders—often phoneme perceptual problems • Tracheotomy—larynx development, tongue movement • Cleft Palate—velopharyngeal problems (resonance—nasality problems)
Dysarthria • Neurological disorders with weak speech production • "Slurred" speech • Speaking softly or barely able to whisper • Slow rate of speech • Rapid speech rate with a "mumbling" quality • Limited tongue, lip, and jaw movement • Abnormal intonation (rhythm) when speaking • Hoarseness, breathiness • Drooling or poor control of saliva • Chewing and swallowing difficulty Sample
Slope index • This parameter is measured in Hz per msec, is based on the relationship between the F2 transitions and place of articulation
“Deaf Speech” • Individuals with congenital or pre-lingual hearing loss vs. post-lingual loss • Loss of speech intelligibility • Difficulty in segmental aspects of speech • Difficulty in control of suprasegmental aspects of speech • Difficulty co-articulating
Segmental Problems • Most frequent errors in spoken language of deaf • Vowel problems (tend to neutralize vowels) • F1/F2/ charts shows marked limitations in both horizontal and vertical degree of tongue movements for vowels • Consonant errors common—omissions and substitutions involving voicing and manner of artic • Place of production errors common because of imprecise tongue position and reduced articulatory movement
Acoustic Analysis of Speech • Alveolar and velar stops produced further back in the vocal tract than normal • Provides clues for speech therapy
Suprasegmental Aspects • Incorrect Fo in word and sentence production • Not enough variation in Fo to differentiate between declarative vs. interrogative utterances Sample
Speech Therapy Emphasis • Some programs put emphasis on speech in education process, others some, and yet others put none • Maasen & Povel (1985) research showed improving segmental production caused 50% improvement in intelligibility with major increase resulting from correcting vowel production
Instrumentation in Treatment • Residual hearing • Visual cues • Spectrographic displays • Palatometry • Glossometry
Palatometry • Device that consists of electrodes mounted on a thin acrylic plate which is custom made to cover the individual’s hard palate and upper teeth and measures tongue and palate contact patterns from electrodes.
Glossometry • Device that consists of electrodes mounted on a thin acrylic plate which is custom made to cover the individual’s hard palate and upper teeth and measures optical tracking of tongue surface using LED.
Phonological Disorders • Speech disorder known as an articulation disorder. • Do not use some or all of the speech sounds expected for their age group. • Phonological processes • Children use alternative articulation or simpler articulatory gestures in place of the adult model • May produce a /t/ for /k/ sound • Sample
Tracheostomy • Surgical procedure to create an opening through the neck into the trachea • Developmental consequences in infants including: • Prevention of larynx from making developmental descent • Thus limiting movement of tongue • Reduction in articulatory movements • Alteration of resonance characteristics • Sample • Sample
Cleft Palate • Congenital split in the roof of the mouth. • Resonance issues • High incidence of conductive hearing loss (typically middle ear infections) Sample Sample Sample