Summary of: Elberling, C., Kristensen, S. G., & Don, M. (2012). Auditory brainstem responses to chirps delivered by different insert earphones. The Journal of the Acoustical Society of America, 131(3), 2091–2100. https://doi.org/10.1121/1.3677257
This paper describes a research project which compares the ABRs in 11 normal-hearing young adults (N = 22 ears) in response to the Click, the CE-Chirp and the LS-Chirp (ref. 17) at a broad range of stimulus levels. The stimuli are delivered by two different insert earphones, the ER-3A and the ER-2. The ER-3A has an amplitude response that rolls of at about 4 kHz, whereas the ER-2 has an amplitude response which is flat all the way up to and beyond 10 kHz. The recordings are obtained with the Eclipse using a 30 nV background noise stop criteria and weighted averaging. For both chirps it is found that the ABRs at lower levels (i.e. below 60 dB nHL) are significantly larger with the ER-2 than with the ER-3A earphone, and further it is demonstrated that this finding most likely is due to the large differences between the amplitude-frequency responses of the two earphones.
Related course: Beyond the Basics: Threshold ABR