Audiological assessment using click auditory brainstem response and chirp auditory steady-state response in pediatric patients with congenital microtia under 36 months: A single-center experience.

OBJECTIVE: To investigate the audiological characteristics of congenital microtia (CM), and explores the effectiveness of click auditory brainstem responses (c-ABR) and chirp auditory steady-state responses (chirp-ASSR) in assessing hearing loss in affected children.

METHODS: Audiological assessments were performed using c-ABR and chirp-ASSR in infants and toddlers under 36 months with CM who were unable to cooperate for behavioral testing. We used c-ABR to assess the nature of hearing loss. Spearman coefficients were used to evaluate correlations, and differences were assessed by subtracting c-ABR air conduction (AC) thresholds from chirp-ASSR AC thresholds. Additionally, differences were analyzed based on the external auditory canal status, auricle status, unilateral or bilateral CM.

RESULTS: The findings indicate that most CM patients experience conductive hearing loss (CHL, 90.36 %) and mixed hearing loss (MHL, 8.21 %), with a smaller number exhibiting normal (0.71 %) or sensorineural hearing loss (SNHL, 0.71 %). Across the entire sample, ABR thresholds showed the strongest correlation with ASSR thresholds at an average of 2-4 kHz (r = 0.723). Chirp-ASSR was found to be a complementary test to c-ABR for screening hearing loss in CM patients, particularly when behavioral testing is not feasible. Significant differences were found in patients with external auditory canal atresia and stenosis, as well as in those with different auricle statuses (Grade I + II, and Grade III).

CONCLUSION: The study supports the use of c-ABR and chirp-ASSR as valuable tools in the audiological assessment of congenital microtia, aiding in early diagnosis and appropriate intervention for hearing loss in pediatric patients.