Summary of: Elberling, C., & Don, M. (2008). Auditory brainstem responses to a chirp stimulus designed from derived-band latencies in normal-hearing subjects. The Journal of the Acoustical Society of America, 124(5), 3022–3037. https://doi.org/10.1121/1.2990709
This paper describes how the temporal dispersion in the human cochlea can be compensated for by using a chirp designed from estimates of the cochlear delay based on derived-band auditory brainstem response (ABR) latencies. To evaluate inter-subject variability and level effects of such delay estimates, a large dataset is analyzed from (N = 81) normal-hearing adults (fixed click level) and from a subset thereof (different click levels). At a fixed click level, the latency difference between 5700 and 710 Hz ranges from about 2.0 to 5.0 ms, but over a range of 60 dB, the mean relative delay is almost constant. Modelling experiments demonstrate that the derived-band latencies depend on the cochlear filter build up time and on the unit response waveform. Because these quantities are partly unknown, the relationship between the derived-band latencies and the basilar membrane group delay cannot be specified. A chirp based on the above delay estimates is used to record ABRs in 10 normal-hearing adults (20 ears). For levels below 60 dB nHL, the gain in amplitude of chirp-ABRs to click-ABRs approaches two, and the effectiveness of chirp-ABRs compares favourably to Stacked-ABRs obtained under similar conditions.
Related course: An Introduction to the CE-Chirp®