耳鼻喉科Otolaryngology topic ten: Speech and voice

Speech and voice

1. Anatomy

-- ventricular folds

-- ventricle

-- true vocal folds

2. Histology

Three layers forming vocal fold

-- epithelium

-- lamina propria

    -->superficial layer = Reinke's space: loose, containing fluid, between mucosa and vocal ligament, determining timbre

    -->intermediate layer

    -->deep layer

-- muscle layer (posterior cricoarytenoid muscle--> abduction; stimulated by recurrent laryngeal nerve)

3. Sound production

-- vibrating frequency: men-->100, women-->200 per second
-- superior laryngeal nerve, recurrent laryngeal nerve

4. Tools for examination/ evaluation

-- laryngeal mirror

-- laryngeal telescope: not elastic, clearer than fiberscope

-- nasopharyngo-laryngo-fiberscope: more elastic, inserted from nose

-- videolaryngo-strobo-scopy: use flash light to record vocal cord movement

-- perceptual evaluation of sound: 0--> best; 3--> worst

-- aerodynamic test- maximum phonation time(MPT): normally >10 secs

-- aerodynamic test- mean flow rate(MFR): MPT↓-->MFR↑

-- acoustic analysis- fundamental frequency

-- acoustic analysis-perturbation measures(jitter: frequency change, % ; shimmer: loudness change, dB)

-- phonetogram(vocal profile): Falsetto with less contact surface, vocal fry with more contact surface 

-- laryngeal electromyography

5. Functional voice disorders

Muscular tension dysphonia

-- overuse of vocal cords

-- hyperfunctional 

Chronic chorditis

-- overuse of vocal cords, heavy smokers

Vocal nodules

-- overuse of vocal cords, wrong speaking habit

-- bilateral, hourglass shape vocal cords

-- DDx: polyp

Vocal polyp

-- phonotrauma 

-- unilateral, bleeding 

Cordal cyst

-- hard to distinguish from polyp, may need patho proof

-- less effect on sound comparing to polyp

Contact ulcer (granuloma)

-- post trachea tube insertion

-- posterior 1/3

Ventricular dysphonia 

-- using ventricular fold when speaking

Conversion (hysterical) dysphonia

-- long term or sudden onset emotional stress

-- recover when the patient cannot hear himself/herself

Mutational falsetto

-- resist voice change during puberty

6. Organic voice disorders

-- senile atrophy, androphonia, hypothyroidism

-- inflammation: Reinke's edema(heavy smokers), infection, irritant exposure, granuloma

-- congenital: sulcus vocalis, glottic web

-- neuromuscular: paralysis(unilateral), spasmodic(treat with botulism) 

-- neoplastic: need to DDx via scope and patho, leukoplakia, papilloma, carcinoma

-- vascular

7. Articulate disorders

-- mental

-- CNS

-- hearing

-- functional, structural