Measurement of thresholds using Chirp-ABR in children with auditory neuropathy spectrum disorder and sensorineural hearing loss.

Aim: This study explored the value of Chirp-auditory brainstem response (ABR) thresholds in assessing the hearing threshold of children diagnosed with auditory neuropathy spectrum disorder (ANSD).

Methods: A total of 20 children with ANSD (40 ears, aged 1.5-7.0 years, median age 4.5 years) and 31 children with sensorineural hearing loss (SNHL) (52 ears, aged 0.9-8.0 years, median age 3.7 years) were included. Besides, 25 normal children (50 ears, aged 0.8-7.5 years, median age 4.6 years) were used as controls. Chirp-ABR and behavioral audiometry were performed simultaneously among three groups of children, allowing for a comparison of the thresholds obtained through both methods.

Results: In ANSD children, the correlation (r-values) between the thresholds obtained from Chirp-ABR and behavioral audiometry at 500-4000 Hz were 0.84, 0.67, 0.59, and 0.60, respectively. The average threshold differences between two methods ranged from 9.7 to 13.3 dB at 500-4000 Hz. Notably, 20 % ears (8/40) exhibited considerable discrepancies (>30 dB) in thresholds at certain frequencies. For SNHL children, the r-values between two methods were 0.84, 0.89, 0.92, and 0.93, respectively. The average threshold differences between two methods were 5.7-8.2 dB at 500-4000 Hz. Similarly, in normal children, the average threshold differences between two methods ranged from 6.1 dB to 7.7 dB, the r-values were 0.81, 0.78, 0.80, and 0.80 at 500-4000 Hz, respectively.

Conclusion: Chirp-ABR threshold is not suitable to predict the behavioral audiometry threshold in ANSD children. When there is a significant discrepancy (>30 dB) between Chirp-ABR thresholds and behavioral audiometry thresholds in hearing loss, ANSD should be highly suspected.