CHAPTER 8 VOICE AND RESONANCE DISORDERS Chapter Learning Goals Explain the normal processes of phonation Describe the perceptual signs of voice and and resonance resonance disorders Describe voice disorders that are associated with vocal misuse or abuse medical or physical conditions and psychological or stress conditions Describe the primary components of a voice and resonance evaluation Describe the major goals of voice and resonance treatment and effective voice and resonance treatment approaches and techniques Introduction Voice is our primary means of expression and is an essential feature of speech The voice is an emotional outlet that mirrors moods attitudes and general feelings It is a powerful tool that delivers a message and simultaneously adds to the meaning of that message Resonance is the quality of the voice that is produced from sound vibrations in the pharyngeal oral and nasal cavities Failure of the velopharyngeal mechanism to separate the oral and nasal cavities during speech production and swallowing is called velopharyngeal inadequacy VPI In This chapter we extend some of the basic concepts related to normal voice and resonance and discuss disorders of voice associated with vocal misuse and hyperfunction abnormal medical and physical conditions and psychological and stress conditions We will also discuss disorders of resonance related to craniofacial anomalies involving the head and face i e cleft palate Content Outline NORMAL VOICE AND RESONANCE PRODUCTION Vocal Pitch Perceptual correlate of F0 associated with rate of vocal fold vibration measured in hertz Hz the number of complete vibrations per second F0 for men is around 125 Hz women are around 250 Hz and children can be up to 500 Hz At birth the infant larynx is high in the neck and descends shortly after birth The difference in vocal F0 and resulting vocal pitch is due largely to the structure of the vocal folds themselves Although individuals have a habitual speaking frequency the frequency of the voice constantly varies during speech production Monotone voice Result of not varying habitual speaking frequency Varying the pitch of the voice has linguistic significance Modifications in the length and tension of the vocal folds are necessary to produce pitch change Vocal Loudness The perceptual correlate of intensity measured in decibels dB The loudness of conversational speech averages around 60 dB Changes in vocal intensity require the vocal folds to stay together longer but alveolar pressure is the major determinant of vocal intensity Resonance Normal resonance is largely determined by the velopharyngeal structures and the adequacy of their function Structures of the velopharyngeal mechanism include the velum the lateral pharyngeal walls and the posterior pharyngeal wall The velopharyngeal port remains open most of the time to allow for nasal breathing and for nasal consonants but must achieve complete or nearly complete closure for production of oral speech sounds VOICE DISORDERS Deviations may be in voice quality pitch loudness and flexibility Approximately 3 6 of school age children and 3 9 of adults in the US have a voice disorder Voice disorders in children are usually related to vocal misuse abuse and are typically temporary but adult voice disorders are quite varied Perceptual signs and case history are initial benchmarks in differential diagnosis Divided into five categories Pitch loudness quality nonphonatory behaviors and aphonia Disorders of Vocal Pitch Monopitch Lacks normal inflectional variation and sometimes the ability to change pitch May be a sign of neurological impairment psychiatric disability or personality Inappropriate pitch A voice that is judged outside the normal range for age and or sex A vocal pitch that is too high may indicate underdevelopment of the larynx A vocal pitch that is too low may be related to endocrinological problems May be related to personal preference or Pitch breaks Sudden uncontrolled upward or downward changes in pitch Common in males going through habit puberty Laryngeal pathologies and or neurological conditions are related to pitch breaks Disorders of Vocal Loudness Monoloudness Lacks normal variations in intensity or ability to change vocal loudness May reflect neurological impairment psychiatric disability or personality Loudness variations Extreme variations in vocal intensity Loss of neural control of the respiratory laryngeal mechanism or psychological problems Disorders of Vocal Quality Hoarseness roughness Lacks clarity and the voice is noisy vocal fold vibration Can be due to pathologies that affect Can also be temporary resulting from minor vocal misuse abuse that produces edema Breathiness The perception of audible air escaping through the glottis during phonation May be related to a lesion that prevents closure or a neurological impairment Vocal tremor Variations in pitch and loudness that are not under voluntary control Usually an indication of a loss of CNS control over the laryngeal mechanism Strain and struggle Related to difficulties initiating and maintaining voice Usually related to neurological impairments or sometimes psychological problems Nonphonatory Vocal Disorders Stridor Noisy breathing or involuntary sound that accompanies inspiration and expiration Indicative of narrowing somewhere in the airway and is always abnormal and serious Throat clearing is normal but is abnormal when it occurs with excessive frequency Consistent aphonia Persistent absence of voice perceived as whispering May be related to vocal fold paralysis disorders of the CNS or psychological problems Episodic aphonia Uncontrolled unpredictable aphonic breaks CNS disorders and psychological problems can contribute Many perceptual signs can be objectively quantified with clinical instruments Objective assessments are valuable for diagnosis and monitoring improvement Three general etiologies of voice disorders are vocal misuse or abuse functional medical or physical conditions organic and psychological or stress conditions Voice Disorders Associated with Vocal Misuse or Abuse Vocal misuse and abuse contribute to structural damage of vocal fold tissue Vocal abuse is harsher than misuse with a greater risk of injuring vocal fold tissue Vocal nodules Localized growths resulting from frequent hard vocal fold collisions Generally bilateral occurring at the juncture of the anterior one third and posterior two thirds of the vocal folds Nodules are soft and pliable at
View Full Document
Unlocking...