Ch 9 The Voice Voice Disorders pgs 258 273 November 11 2011 Vocal Pitch and the Pitch Changing Mechanism Pitch Perceptual correlate of F0 fundamental frequency o Fundamental frequency aka habitual pitch rate of vocal fold vibration During one complete vibratory cycle of vocal fold vibration the vocal folds move from a closed or adducted position to an open or abducted position and back to the closed position Fundamental frequency and pitch measured in hertz Hz number of complete vibrations per second Optimal pitch level most suitable pitch determined by vocal fold structure o Men 130 Hz o Women 250 Hz o Children up to 500 Hz o Every individual has their own optimal pitch level At birth larynx is high in neck for breathing and feeding simultaneously o Vocal folds are about 3mm long Female vocal folds only lengthen 12 5 17mm do not thicken Male vocal folds lengthen 17 20mm and thicken Monotone voice result of not varying habitual speaking frequently o Most people can vary pitch based on meaning emotion etc Pitch change o Lengthening and tensing increase pitch Females have shorter vocal folds so they will be tighter when stretched 1 o Relaxing intrinsic muscles decreases pitch Vocal Loudness and the Loudness Changing Mechanism Vocal loudness perceptual correlate of intensity o Sound waves and hearing thresholds measured in decibels dB o Changed with intensity o Normal conversational speech 60 dB Changes in vocal loudness o Require vocal folds to stay together longer o Alveolar pressure is major determinant every time air pressure doubles there is an 8 12 dB increase in vocal intensity Disorders of Voice Deviations in quality pitch loudness flexibility Majority of case load for voice disorders 1 teachers 2 telemarketers 3 lawyers o People who are constantly using their voice on daily basis for long periods of time without voice training Can affect people of any age Children Usually related to vocal abuse misuse and usually temporary 3 6 have voice disorder Adults more variable causes 3 9 have voice disorder men more affected than women Differential diagnosis perceptual signs quality loudness etc and case history give examples of everyday habits of individuals Disorders of Vocal Pitch o Monopitch no voluntary pitch variation o Inappropriate pitch voice is outside the normal pitch range for age and or sex i e adult males sound like boys o Abnormal pitch break up the rhythm of speech common in boys going through puberty Disorders of Vocal Loudness 2 o Cerebral palsy influences vocal loudness because it can affect muscles of the chest area which plays a large role in breathing o Monoloudness no voluntary change in loudness intensity o Loudness variations extreme variations in vocal intensity in which the voice is either too soft or too loud for the particular speaking situation Disorders of Vocal Quality o Hoarseness roughness o Breathiness the perception of audible air escaping through the glottis during phonation indicates inadequate closure of the glottis during vocal fold vibration Normal female voices are perceived to be more breathy than normal male voices Also young women use more air than young men to produce a syllable o Vocal tremor variation in pitch or loudness involuntary o Strain and struggle person has difficulty initiating and maintaining vocal ability Voice fades in and out and actual stoppages can occur Nonphonatory Vocal Disorders o Nonphonatory no phonation vocal fold vibration occurring o Stridor noisy breathing accompanies inhalation and exhalation Indicative of a blockage of the airway Can be due to other medical conditions Can be indicative of other things o Excessive throat clearing vocal folds slammed together abruptly Clearing mucous from the vocal folds o Most common Consistent aphonia voice is persistently absent sounds like the person is whispering all the time paralysis Related to psychological problems neurological disorders or vocal fold Episodic aphonia aka uncontrolled unpredictable aphonia speak in normal tone of voice and suddenly change to whispering involuntarily 3 Vocal Misuse and Abuse psychological cause o Causes of all voice disorders vocal misuse abuse functional physical cause organic o Contribute to structural damage of vocal folds o Abuse is harsher than misuse easier to remediate behaviors for misuse than for abuse i e drinking smoking etc Abuse is likely to permanently damage vocal fold tissue beyond repair Can result in o Vocal nodules growths on vocal folds due to hard and frequent contact Bilateral occur on both vocal folds Start of soft and pliable and later become hard and fibrous interfering with vocal fold vibration Most common in women between 20 50 years of age but can also occur in kids prone to excessive loud talking especially in boys Primary perceptual symptom hoarseness or breathiness Treat periods of vocal rest and trying to remediate those situations which cause the misuse of the vocal folds o Contact ulcers red sores on the vocal folds Can be painful and can radiate to the ear Bilateral Most common with people with heart worms and reflux Throat clearing and vocal fatigue are common Best treatment managing the reflux if reflux is decreased the ulcers can heal themselves o Vocal polyps fluid filled lesions on vocal folds Unilateral Can result from a single incident i e yelling at a sporting event 4 Sessile flat over 2 3 of the vocal fold Pedunculated stock like like broccoli does not cover the whole vocal fold because it branches out in small heads Feels like something is in your throat Hoarseness and breathiness Surgical removal often necessary o Acute and chronic laryngitis swelling of the vocal folds Acute temporary usually caused by a cold or allergies if comes from vocal fold abuse that cannot be remediated it can become chronic Chronic permanent comes from abusive behaviors especially behaviors that dry out the vocal folds stridor caffeine alcohol smoking Appears swollen can cause atrophy wasting away of vocal fold tissue can become dry and sticky persistent cough and throat aches Hoarseness and some aphonia Associated with Medical or Physical Conditions Organic Voice Disorders o CNS disorders Dysarthia muscle weakness discoordination tremor paralysis Results in Adduction coming together of vocal folds normal Hypoadduction not enough vocal fold closure vocal quality is whispery Parkinson s Disease muscle rigidity tremor slowness of movement breathiness o Voice symptoms monopitch monoloudness harshness Vocal fold