Andre M Marcoux1. 1. Department of Audiology and Speech Language Pathology, University of Ottawa, 451 Smyth Rd., Ottawa, Ontario, K1H 8M5, Canada. amarcoux@uottawa.ca
Abstract
OBJECTIVE: The objective of this study was to quantify the maturation of the Auditory Brainstem Response (ABR) at discrete periods during infancy and to provide a means to appropriately estimate hearing thresholds when the ABR is immature. METHODS: A longitudinal study was designed to measure the in situ ABR thresholds of infants using air-conduction tone bursts of 500, 2000 and 4000Hz. Thresholds were measured using an eardrum-level microphone to eliminate the bias related to coupler-referenced scales such as the dB nHL scale used for adult assessments. RESULTS: The study found that the in situ thresholds of a sample of normally developing infants decreased significantly during the first 6 months of life. A comparison of these in situ thresholds with those of normal-hearing adults revealed that the ABR response reached maturity in these infants between 4 and 6 months of age for the frequencies 500 and 2000Hz but remained immature, or elevated, at 6 months of age for 4000Hz. CONCLUSIONS: The maturation of the ABR should be considered during the estimation of an infant's audiogram and subsequent diagnosis. Copyright Â
OBJECTIVE: The objective of this study was to quantify the maturation of the Auditory Brainstem Response (ABR) at discrete periods during infancy and to provide a means to appropriately estimate hearing thresholds when the ABR is immature. METHODS: A longitudinal study was designed to measure the in situ ABR thresholds of infants using air-conduction tone bursts of 500, 2000 and 4000Hz. Thresholds were measured using an eardrum-level microphone to eliminate the bias related to coupler-referenced scales such as the dB nHL scale used for adult assessments. RESULTS: The study found that the in situ thresholds of a sample of normally developing infants decreased significantly during the first 6 months of life. A comparison of these in situ thresholds with those of normal-hearing adults revealed that the ABR response reached maturity in these infants between 4 and 6 months of age for the frequencies 500 and 2000Hz but remained immature, or elevated, at 6 months of age for 4000Hz. CONCLUSIONS: The maturation of the ABR should be considered during the estimation of an infant's audiogram and subsequent diagnosis. Copyright Â
Authors: Katlyn B Van Dyke; Rachel Lieberman; Alessandro Presacco; Samira Anderson Journal: J Speech Lang Hear Res Date: 2017-08-22 Impact factor: 2.297