Comparison of threshold estimation in infants with hearing loss or normal hearing using auditory steady-state response evoked by narrow band CE-chirps and auditory brainstem response evoked by tone pips

Objective: The objective of this study is to compare air-conduction thresholds obtained with ASSR evoked by narrow band (NB) CE-chirps and ABR evoked by tone pips (tpABR) in infants with various degrees of hearing loss. Design: Thresholds were measured at 500, 1000, 2000 and 4000Hz. Data on each participant were collected at the same day. Study sample: Sixty-seven infants aged 4 d to 22 months (median age=96 days), resulting in 57, 52, 87 and 56 ears for 500, 1000, 2000 and 4000Hz, respectively. Results: Statistical analysis was performed for ears with hearing loss (HL) and showed a very strong correlation between tpABR and ASSR evoked by NB CE-chirps: 0.90 (n=28), 0.90 (n=28), 0.96 (n=42) and 0.95 (n=30) for 500, 1000, 2000 and 4000Hz, respectively. At these frequencies, the mean difference between tpABR and ASSR was -3.6dB (+/- 7.0), -5.2dB (+/- 7.3), -3.9dB (+/- 5.2) and -5.2dB (+/- 4.7). Linear regression analysis indicated that the relationship was not influenced by the degree of hearing loss. Conclusion: We propose that dB nHL to dB eHL correction values for ASSR evoked by NB CE-chirps should be 5dB lower than values used for tpABR.