Crying abnormalities in congenital hypothyroidism: preliminary spectrographic study.

The aim of this preliminary study was to evaluate the acoustic patterns of the cries of hypothyroid newborns at the time of diagnosis and after the beginning of therapy. Cries were recorded at the nursery of the San Raffaele Hospital, Milan, Italy from 12 full-term subjects (three boys and nine girls) affected by congenital hypothyroidism. Results show that untreated hypothyroid infants at first recording had fewer voiceless and partially voiced cries than normal controls. The percent distribution of this pattern did not change at the second recording after the onset of substitutive therapy. Also, untreated hypothyroid infants had many more cry units showing a vibrato contour than did controls, and this pattern did not change after the onset of treatment. Starting, maximum, minimum, and end frequencies measured on the fundamental were significantly lower in the hypothyroid sample. Four hypothyroid subjects recorded before therapy and within 4 weeks after therapy onset significantly augmented their fundamental frequency parameters; however, in 25% of the sample, sound parameters remained unaltered after 3 or more weeks of treatment. To our knowledge the present preliminary study is the first one performed on follow-up of hypothyroid newborns and indicates that both central and peripheral damage might influence the pattern of crying in untreated hypothyroid infants.