Dysphonia in infants.

The definition of infant dysphonia is difficult because the physiological phonation itself may be extremely variable in newborns. In a wider sense, all voice utterings can be interpreted as dysphonia which deviate continuously in any of the parameters (timbre, pitch, intensity, or noise) from the normal. We differentiated 20 types of such pathological phonation. The most characteristic are: the hoarse (caused by inflammation or tumor of the vocal cords); the hollow (indicative of tracheal stenosis); the shrill (suggesting a CNS damage); the bleating (pathognostic of Down syndrome); the faint (a result of myogenic diseases); and the mewing cry (etiology: cri-du-chat syndrome). In a narrower sense dysphonia in infants is a kind of pathological phonation without evidence of neurological alteration or chromosomal aberration and without a verified laryngeal lesion. These infants utter pressed, harsh, or very high voice (hyperfunctional form) or a weak, inert cry (hypofunctional form). The dysphonic voice may be characterized also by sudden change in melody or in pitch (glide, shift, break, bitonality) and by turbulent noises. This type of newborn dysphonia is a result of the immature innervation of the larynx, it gradually improves and lateron spontaneously disappears. Perceptual evaluation, endoscopy, and acoustic analysis yield useful diagnostic information.