Cry features in siblings of SIDS.

AIM To examine the acoustic features of crying demonstrated by infants whose older sibling died of sudden infant death syndrome (SIDS) and compare these features to a nonrisk group of infants. METHODS Pain-induced crying episodes were collected from a group of healthy term (HT) infants and siblings of SIDS infants. One complete crying episode was obtained from each infant and analyzed acoustically with regard to durational and spectral features. RESULTS The cries of SIDS siblings were found to be significantly higher in pitch and reflected hyperadductory vocal fold vibratory behaviour compared to the HT group. There were no group differences with regard to durational features of crying. CONCLUSIONS The laryngeal behaviour of infant crying, as inferred via acoustic analyses, differs between HT infants and siblings of SIDS infants. Accordingly, acoustic features of infant crying may serve as an additional diagnostic marker in the identification of children who may be at risk for SIDS.