Comparing Simultaneous Electrocochleography and Auditory Brainstem Response Measurements Using Three Different Extratympanic Electrodes

Abstract

Background Various extratympanic recording electrodes have been used to make electrocochleography (ECochG) and auditory brainstem response (ABR) measurements in clinics, translational research, and basic science laboratories. However, differences may exist in ECochG and ABR measurements depending on the different types of extratympanic electrodes that are used. Purpose The purpose of this research is to compare simultaneously recorded ECochG and ABR responses using three different extratympanic electrodes. This research helps clinicians and researchers to understand how electrode types and recording sites influence EcochG and ABR results. In addition, our findings could provide more normative data to the ECochG and ABR literature as well as give perspective on a preferred electrode approach when performing simultaneous ECochG and ABR testing. Research Design Ours was a repeated-measures study with measurements being made from individual participants on two separate sessions. Study Sample Twenty young adult females with normal hearing. Procedure A three-channel recording system was used to simultaneously record ECochG and ABR measurements in response to alternating polarity click stimuli. In each session, measurements were simultaneously recorded with a TipTrode electrode and one of the tympanic membrane (TM) electrodes. Data Collection and Analysis Suprathreshold summating potential (SP) and action potential (AP) of the ECochG and waves I, III, and V of the ABR, and threshold responses (AP and wave V) were identified. Results Compared with the ear canal TipTrode electrode, TM electrodes yielded suprathreshold amplitudes that were larger than those from the ear canal electrode, smaller SP–AP ratios, lower AP thresholds, and less variability. These findings can help guide choices made by clinicians, translational investigators, and basic science researchers on which type of extra-tympanic electrode to use for their intended purpose.

Exploring Electrode Placements to Optimize the Identification and Measurement of Early Auditory Evoked Potentials

“…It is important to acknowledge that the inverting electrode used for this study's recordings was an ear canal electrode (TIPtrode) rather than a tympanic membrane (TM) electrode, another popular option for ECochG recordings. While TIPtrodes have been shown to produce smaller amplitudes and higher variability [29] than TM electrodes, the current study chose to use the TIPtrode due to its ease of use, patient comfortability, and familiarity with audiologists (including personnel involved in data collection). It should be noted that, with proper training, similar levels of patient comfort and clinician efficiency can be achieved with TM electrodes, and they should remain at the top of the options under consideration when recording ECochGs in clinical and research settings alike.…”

“…It should be noted that, with proper training, similar levels of patient comfort and clinician efficiency can be achieved with TM electrodes, and they should remain at the top of the options under consideration when recording ECochGs in clinical and research settings alike. Importantly, the quantitative differences between TM electrodes and ear canal electrodes are observed only for standard ECochG measures including SP and SP/AP ratio [29]. How variability differs between these electrodes for peak-to-trough amplitudes of Wave I and Wave II has been less reported on.…”

No effect of occupational noise exposure on auditory brainstem response and speech perception in noise

“…In addition, an extra-tympanic electrode (Lilly TM-Wick, IHS, Miami, FL, United States) was placed in the ipsilateral external auditory canal, sitting at the tympanic membrane (inverting electrode). This placement was chosen to improve the visualization of wave I and reduce intrasubject variability (Lefler et al, 2021). The amplifier bandpass was set between 0.3 and 3 kHz.…”

Examining the Profile of Noise-Induced Cochlear Synaptopathy Using iPhone Health App Data and Cochlear and Brainstem Electrophysiological Responses to Fast Clicks Rates

“…with surface electrodes or TipTrode recording. 32,35 ECochG responses were recorded using a horizontal montage (contralateral mastoid TM-electrode) and ABRs were recorded with a vertical montage (Fz-TM electrode) and a common ground electrode. Electrode impedances were kept between 2 and 5 kV.…”

“…Majority of studies were done using an ear canal TipTrode electrode to record ECochG 16 or/and ABR, 26 and disposable surface electrodes to record ABR in humans, 21,27 which yield small and variable response amplitudes than when recording using a tympanic membrane electrode. 32 Stimulus rate is another factor that could affect response latency and amplitude. Recording at fast click rates (e.g., 50-100 clicks/s) is usually used for neurodiagnostic evaluation to assess neural adaptation, and the recorded response is usually analyzed using the conventional signal averaging procedure.…”