Effects of analysis window on 40-Hz auditory steady-state responses in cochlear implant users

In this study, we used the intermittent paradigm to evoke eASSRs in adult CI users and investigated whether the early response buildup affects the response measurement outcomes. To this end, we varied the starting timepoint and length of the analysis window within which the responses were analysed. We used the amplitude, signal-to-noise ratio (SNR), phase, and pairwise phase consistency (PPC) to characterize the responses. Moreover, we set out to find the optimal stimulus duration for efficient and reliable eASSR measurements. These analyses were performed at two stimulation levels, i.e., 100% and 50% of the dynamic range of each participant. Results revealed that inclusion of the first 300 ms in the analysis window leads to overestimation of response amplitude and underestimation of response phase. Additionally, the response SNR and PPC were not affected by the inclusion of the first 300 ms in the analysis window. However, the latter two metrics were highly dependent on the stimulus duration which complicates comparisons across studies. Finally, the optimal stimulus duration for quick and reliable characterization of eASSRs was found to be around 800 ms for the stimulation level of 100% DR. These findings suggest that inclusion of the early onset period of eASSR recordings negatively influences the response measurement outcomes and that efficient and reliable eASSR measurements are possible using stimuli of around 800 ms long. This will pave the path for the development of a...

Source: Hearing Research - September 9, 2023 Category: Audiology Authors: Wouter David Elise Verwaerde Robin Gransier Jan Wouters Source Type: research