Habituation of the blink reflex in the neonatal period and development of auditory processing.

OBJECTIVE To check the existence of an association between the presence/absence of the blink reflex habituation in the neonatal period and auditory processing development. METHODS The occurrence of blink reflex habituation was studied in 33 neurologically normal neonates, aged between 9 and 25 months, who had their behavioral responses analyzed and classified according to Azevedo (1993). Habituation of the blink reflex was verified using 90-dB sound stimulus. The stage of auditory processing development was evaluated through 41-dB sound stimulus. Statistical data were analyzed with Fischer and χ2 tests. RESULTS Out of the 33 studied children, 22 presented blink reflex habituation in the first stage of the study. In 7 of them, the auditory processing stage matched their chronological age, while in 15 of them the auditory processing stage was not in accordance with their chronological age. Eleven children failed to present habituation of the blink reflex in the first stage of the study. From this group, eight children presented auditory responses that were appropriate to their chronological age, whereas three had inappropriate responses. A statistically significant association between the presence of blink reflex habituation and auditory processing delay was verified, in addition to an association between the absence of the blink reflex habituation and chronologically suitable responses. CONCLUSIONS The presence of blink reflex habituation in the neonatal period does not seem to be a predictive factor of suitable auditory processing.