[Spectrographic analysis of the crying of infants with laryngeal disorders]

Twenty induced pain cries from the same number of infants with laryngeal disorders (infectious laryngitis, laryngomalacia, recurrens paresis and subglottic stricture) have been analyzed by means of sound spectrography. For each cry 21 phonetical cry features have been evaluated. This cry material was then compared with 120 pain cries from healthy infants. In the pathological group a significant increase could be noted in the occurrence of the following cry attributes: second pause, abnormal melody types, instability of the fundamental frequency, biphonation, vibrato, half-voiced voice quality, and inspiratory stridor. Furthermore, a significant decrease could be noticed in the occurrence of voiceless voice quality and glottal roll. For the other cry parameters no significant differences have been observed. In the light of these findings, the neuropathognomic significance, which has been up to now attached to such spectrographic features as very high maximum pitch, biphonation, gliding, and abnormal melody type, should not be taken too strictly. Moreover, one may conclude that the actual state of cry spectrography does not permit us to regard such parameters as instability of the fundamental frequency and noise concentration as indicators of neurologic disorders. On the other hand, the features inspiratory stridor, vibrato and tonal pit seem, to be to a certain extent typical of peripheral diseases of the vocal tract.