Cochlear Response Telemetry

Campbell, Luke; Kaicer, Arielle; Briggs, Robert; O’Leary, Stephen

doi:10.1097/mao.0000000000000678

Cited by 90 publications

(57 citation statements)

References 26 publications

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“…Electrocochleography was recorded using the Cochlear Response Telemetry (CRT) system previously described by the investigators (Campbell et al, 2015, 2016). Acoustic stimuli were generated digitally using a USB data acquisition card (DT9847, Data Translation, USA), and presented using an ER3A insert earphone (Etymotics, USA).…”

Section: Methodsmentioning

confidence: 99%

“…To estimate the CM and ANN components of the ECochG waveform, the recordings were processed by either adding the alternating phases responses (SUM) to estimate the ANN or by subtracting them (DIF) to estimate the CM (Adunka et al, 2006; Choudhury et al, 2012; Campbell et al, 2015). To isolate the magnitude of the stimulus frequency-matching CM in the DIF trace, the magnitude at the stimulus frequency was calculated by Fast Fourier Transform (FFT).…”

Section: Methodsmentioning

confidence: 99%

“…Contrary to Calloway et al (2014), all eight participants exhibited ECochG responses with relatively constant amplitude across the array, or showed a peak in the CM response on basal electrodes in response to 0.5- or 1-kHz tones. It was suggested that the unexpectedly flat responses and basal-peak responses arose from the proximity of the electrode to the auditory nerve, or the influence of intra-scalar fibrosis on the current path in the vicinity of the electrode (also suggested by Campbell et al, 2015). In contrast, Formeister et al (2015) made recordings at multiple insertion depths from a single recording electrode on a flexible carrier that was inserted into the cochlea during surgery, just prior to implantation of the commercial CI.…”

Section: Introductionmentioning

confidence: 97%

“…ECochG has recently become available using intra-cochlear electrodes in CI recipients (Calloway et al, 2014; Campbell et al, 2015; Dalbert et al, 2015). It is a cochlear potential derived from neural and sensory sources in response to transient acoustic stimuli presented with alternating polarity.…”

Section: Introductionmentioning

confidence: 99%

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Characterizing Electrocochleography in Cochlear Implant Recipients with Residual Low-Frequency Hearing

et al. 2017

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Objective: Lay the groundwork for using electrocochleography (ECochG) as a measure of cochlear health, by characterizing typical patterns of the ECochG response observed across the electrode array in cochlear implant recipients with residual hearing.Methods: ECochG was measured immediately after electrode insertion in 45 cochlear implant recipients with residual hearing. The Cochlear Response Telemetry system was used to record ECochG across the electrode array, in response to 100- or 110-dB SPL pure tones at 0.5-kHz, presented at 14 per second and with alternating polarities. Hair cell activity, as the cochlear microphonic (CM), was estimated by taking the difference (DIF) of the two polarities. Neural activity, as the auditory nerve neurophonic (ANN), was estimated by taking the sum (SUM) of the two polarities. Prior work in humans and animal studies suggested that the expected ECochG pattern in response to a 0.5-kHz pure tone is an apical-peak in CM amplitude and latency.Results: The most prevalent pattern was a peak in the DIF amplitude near the most apical electrode, with a prolongation of latency toward the electrode tip; this was found in 21/39 individuals with successful ECochG recordings. The 21 apical-peak recipients had the best low-frequency hearing. A low amplitude, long-latency DIF response that remained relatively constant across the electrode array was found in 10/39 individuals, in a group with the poorest low- and high-frequency hearing. A third, previously undescribed, pattern occurred in 8/39 participants, with mid-electrode peaks in DIF amplitude. These recipients had the best high-frequency hearing and a progressive prolongation of DIF latency around the mid-electrode peaks consistent with the presence of discrete populations of hair cells.Conclusions: The presence of distinct patterns of the ECochG response with relationships to pre-operative hearing levels supports the notion that ECochG across the electrode array functions as a measure of cochlear health.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

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Characterizing Electrocochleography in Cochlear Implant Recipients with Residual Low-Frequency Hearing

et al. 2017

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“…This suggested a limited spread of excitation. Campbell et al (2015) recorded from CI patients who retained audiometric thresholds between 75 and 90 dB HL at 500 Hz in their implanted ear. In response to acoustical stimulation they obtained eCAPs including CM and SP responses.…”

Section: Current Interestmentioning

confidence: 99%

Ups and Downs in 75 Years of Electrocochleography

Eggermont

2017

Front. Syst. Neurosci.

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Before 1964, electrocochleography (ECochG) was a surgical procedure carried out in the operating theatre. Currently, the newest application is also an intra-operative one, often carried out in conjunction with cochlear implant surgery. Starting in 1967, the recording methods became either minimal- or not-invasive, i.e., trans-tympanic (TT) or extra tympanic (ET), and included extensive studies of the arguments pro and con. I will review several valuable applications of ECochG, from a historical point of view, but covering all 75 years if applicable. The main topics will be: (1) comparing human and animal cochlear electrophysiology; (2) the use in objective audiometry involving tone pip stimulation—currently mostly pre cochlear implantation but otherwise replaced by auditory brainstem response (ABR) recordings; (3) attempts to diagnose Ménière’s disease and the role of the summating potential (SP); (4) early use in diagnosing vestibular schwannomas—now taken over by ABR screening and MRI confirmation; (5) relating human electrophysiology to the effects of genes as in auditory neuropathy; and (6) intracochlear recording using the cochlear implant electrodes. The last two applications are the most recently added ones. The “historical aspects” of this review article will highlight the founding years prior to 1980 when relevant. A survey of articles on Pubmed shows several ups and downs in the clinical interest as reflected in the publication counts over the last 75 years.

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Intracochlear Electrocochleography and Speech Perception Scores in Cochlear Implant Recipients

et al. 2021

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Objectives/Hypothesis: Previous studies have demonstrated that electrocochleography (ECochG) measurements made at the round window prior to cochlear implant (CI) electrode insertion can account for 47% of the variability in 6-month speech perception scores. Recent advances have made it possible to use the apical CI electrode to record intracochlear responses to acoustic stimuli. Study objectives were to determine 1) the relationship between intracochlear ECochG response amplitudes and 6-month speech perception scores and 2) to determine the relationship between behavioral auditory thresholds and ECo-chG threshold estimates. The hypothesis was that intracochlear ECochG response amplitudes made immediately after electrode insertion would be larger than historical controls (at the extracochlear site) and explain more variability in speech perception scores.Study Design: Prospective case series. Methods: Twenty-two adult CI recipients with varying degrees of low-frequency hearing had intracochlear ECochG measurements made immediately after CI electrode insertion using 110 dB SPL tone bursts. Tone bursts were centered at five octave-spaced frequencies between 125 and 2,000 Hz.Results: There was no association between intracochlear ECochG response amplitudes and speech perception scores. But, the data suggest a mild to moderate relationship between preoperative behavioral audiometric testing and intraoperative ECo-chG threshold estimates.Conclusion: Performing intracochlear ECochG is highly feasible and results in larger response amplitudes, but performing ECochG before, rather than after, CI insertion may provide a more accurate assessment of a patient's speech perception potential.

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Cochlear Response Telemetry

Abstract: Intracochlear responses to acoustic stimulation can be recorded directly from the CI in awake recipients with residual hearing. This may prove useful for monitoring postoperative hearing and for device fitting.

Cited by 90 publications

References 26 publications

Characterizing Electrocochleography in Cochlear Implant Recipients with Residual Low-Frequency Hearing

Characterizing Electrocochleography in Cochlear Implant Recipients with Residual Low-Frequency Hearing

Ups and Downs in 75 Years of Electrocochleography

Intracochlear Electrocochleography and Speech Perception Scores in Cochlear Implant Recipients

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