The acoustic characteristics of the cry of an infant with unilateral vocal fold paralysis.

We have previously shown the acoustic similarity among well, full-term infants of the same post-conceptional and post-partum ages (Int. J. Pediat. Otorhinolaryngol., 10 (1985) 1-8). The objective of that research was to provide a template against which the cries of any given infant may be compared. This paper shows a more detailed analysis of both the normal infants' cries and the cry of an infant with a unilateral vocal fold paralysis. It is evident from this analysis that this infant's cry is not normal as it displays a spectrum not found in the cries of normal infants. What this research shows is that a technique is available with which it is possible to make a screening identification of those infants who merit further investigation. It is an objective of such research to determine if the cry of a given infant is abnormal in specifiable, and therefore diagnostic, ways. In this instance, we can conclude that the cry of this infant differs from that of one with a normal airway.