Thalamocortical Auditory Processing Across the Lifespan: A Study with Speech-Evoked Cortical Potentials

Objective This cross-sectional study aimed to identify electrophysiological markers distinguishing stages of development, stability, and early aging in cortical auditory processing to elucidate neurophysiological changes in healthy auditory aging. Methods We evaluated 149 healthy participants (both sexes; aged 7-59 years) recruited from the general community via electronic media, posters, radio, and regional television, divided into six age groups (7-11, 12-17, 18-29, 30-39, 40-49, and 50-59 years). Eligibility criteria included normal hearing, no neurological disorders, and normal otoscopy. Cortical auditory evoked potentials (CAEPs) were recorded using the syllable /da/ (binaural stimulation, 70 dB HL) with eye-movement control. Results Significant differences in P1 latency were observed between children (7-11 years) and older participants (12-59 years). N1 latency differed between children and adults (30-59 years), while N1 amplitude varied between adolescents (12-19 years) and adults aged 40-49 years. P1–N1 latency differed between adolescents and adults aged 40-59 years. Age correlated moderately negatively with P1/N1 latencies and weakly positively with N1 amplitude. Conclusion Maturational changes in P1/N1 latencies were evident, but no decline occurred during adulthood or pre-senescence, suggesting stable auditory processing until at least age 59.