• Muhammad Sufiyan.S
• M.P. Ravanan
• S. Suresh Kumar
• Suma Sulaiman
• Subin Solomen

Abstract Background: As preterm neonates’ auditory system is underdeveloped, there is a need for auditory monitoring of this population. Electrophysiological thresholds measured through Auditory Steady-State Response (ASSR) which is an objective method were higher in preterm than in full term babies. However there was no difference at 18 months of age between preterm and term babies showing the auditory maturation of preterm infants throughout their development. It is not known at what month ASSR threshold equals for preterm and term babies. It is also not clear about these thresholds in Indian population. Objective: The purpose of this study is to compare the ASSR thresholds in preterm and term infants evaluated at four stages (after birth, nine months, twelve months and fifteen months) in Indian population. Materials & Methods: The study included 120 normal hearing neonates: 60 preterm and 60 term babies. Then neonates underwent assessment of ASSR in both ears simultaneously through insert phones in the frequencies of 500 to 4000Hz with mixed modulation was used. We presented the intensity at a decreasing level to detect the minimum level of responses. At 9, 12, 15 months, 60 preterm infants returned for the new assessment for ASSR and were compared with 60 full-term infants. The data were compared between groups according to gestational age. Results: Electrophysiological thresholds were higher in preterm than in full-term neonates (p < 0.05) at the first, second and third testing (at birth, 9th & 12th months). At 15 months, there was no difference between groups (p > 0.05) in all frequency thresholds (500 Hz, 1000Hz, 2000Hz &4000Hz) Conclusion: In the first, second and third evaluation preterm had higher thresholds in ASSR. There was no difference in fourth evaluation (at 15 months of age) showing the auditory maturation of preterm infants throughout their development. This maturation completes with in fifteen months, three months earlier as compared to previous study.

Evoked potentials, Auditory steady state response (ASSR), Electrophysiology, Premature babies, Preterm babies, Term babies, Neonates, Infants

"Comparison of Auditory Steady State Evoked Potentials Threshold in Preterm and Term Infant at Four Stages in Indian Population", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 6, page no.540-548, June-2018, Available :http://www.jetir.org/papers/JETIR1806675.pdf

"Comparison of Auditory Steady State Evoked Potentials Threshold in Preterm and Term Infant at Four Stages in Indian Population", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 6, page no. pp540-548, June-2018, Available at : http://www.jetir.org/papers/JETIR1806675.pdf