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Updated: Jan 10, 2026

Infant Auditory Processing and Event-related Brain Oscillations
Published on: July 1, 2015
Frequency-Following Response in Infants With Congenital Syphilis
Sheila Andreoli Balen1,2,3, Carolina Karla de Souza Evangelista1,2,4, Teresa Ribas-Prats5,6,7
1Undergraduate Program in Speech, Language and Hearing Sciences, Federal University of Rio Grande do Norte, Natal, Brazil.
Purpose:
This work aimed to study the frequency-following response (FFR) of infants with congenital syphilis under treatment.
Method:
A cross-sectional study with 112 infants recruited at public maternities was conducted. A total of 90 infants were included in the sample and divided into two groups: 53 infants whose mothers and infants received perinatal syphilis treatment and 37 infants whose mothers and infants were free of syphilis (control group). Infant age ranged from 15 to 90 days (M = 39.9 ± 17.2 days). FFRs were recorded to a 170-ms consonant-vowel /da/ stimulus, presented at 80 dB nHL to the right ear. Data were analyzed in the time and frequency domains. The Shapiro-Wilk and Mann-Whitney U tests were applied with a significance level of p ≤ .05.
Results:
No significant between-groups differences were observed in FFR spectral amplitude at the stimulus fundamental frequency or its harmonics, whether computed in the transient or steady portions of the stimulus. No significant differences were observed in prestimulus root-mean-square, neural lag, and the signal-to-noise ratio of the spectral amplitude.
Conclusion:
These findings suggest that infants with congenital syphilis, when appropriately treated at birth, demonstrate preserved auditory pathway function and sound processing, including temporal and spectral characteristics that are relevant for language acquisition.

