Validating an Evoked Potential Platform for Electrocochleography During Cochlear Implantation.

Objective: To validate electrocochleography (ECochG) between an auditory evoked potential (AEP) machine and an established cochlear implant (CI) manufacturer ECochG system.

Methods: Intraoperative validation study at a tertiary referral center. Patients included adults and children undergoing cochlear implantation.

Amplitude Parameters Are Predictive of Hearing Preservation in a Randomized Controlled Trial of Intracochlear Electrocochleography During Cochlear Implant Surgery.

Objective: To prospectively evaluate the association between hearing preservation after cochlear implantation (CI) and intracochlear electrocochleography (ECochG) amplitude parameters.

Study Design: Multi-institutional, prospective randomized clinical trial.

Setting: Ten high-volume, tertiary care CI centers.

The Origin Along the Cochlea of Otoacoustic Emissions Evoked by Mid-Frequency Tone Pips.

Purpose: Tone-pip-evoked otoacoustic emissions (PEOAEs) are transient-evoked otoacoustic emissions (OAEs) that are hypothesized to originate from reflection of energy near the best-frequency (BF) cochlear place of the stimulus frequency. However, individual PEOAEs have energy with a wide range of delays. We sought to determine whether some PEOAE energy is consistent with having been generated far from BF.

Electrocochleography-Based Tonotopic Map: II. Frequency-to-Place Mismatch Impacts Speech-Perception Outcomes in Cochlear Implant Recipients.

Objectives: Modern cochlear implants (CIs) use varying-length electrode arrays inserted at varying insertion angles within variably sized cochleae. Thus, there exists an opportunity to enhance CI performance, particularly in postlinguistic adults, by optimizing the frequency-to-place allocation for electrical stimulation, thereby minimizing the need for central adaptation and plasticity. There has been interest in applying Greenwood or Stakhovskaya et al.

Identifying Slim Modiolar Electrode Tip Fold-Over With Intracochlear Electrocochleography.

Objective: To evaluate the predictive value of intracochlear electrocochleography (ECochG) for identifying tip fold-over during cochlear implantation (CI) using the slim modiolar electrode (SME) array.

Study Design: Prospective cohort study.

Setting: Tertiary referral center.

Improved Cochlear Implant Performance Estimation Using Tonotopic-Based Electrocochleography.

Importance: Cochlear implantation produces remarkable results in postlingual deafness, although auditory outcomes vary. Electrocochleography (ECochG) has emerged as a valuable tool for assessing the cochlear-neural substrate and evaluating patient prognosis.

Objective: To assess whether ECochG-total response (ECochG-TR) recorded at the best-frequency electrode (BF-ECochG-TR) correlates more strongly with speech perception performance than ECochG-TR measured at the round window (RW-ECochG-TR).

Factors Affecting Performance in Adults With Cochlear Implants: A Role for Cognition and Residual Cochlear Function.

Objective: To evaluate the impact of preoperative and perioperative factors on postlinguistic adult cochlear implant (CI) performance and design a multivariate prediction model.

Study Design: Prospective cohort study.

Setting: Tertiary referral center.

Place Coding in the Human Cochlea.

Unlabelled: The cochlea's capacity to decode sound frequencies is enhanced by a unique structural arrangement along its longitudinal axis, a feature termed 'tonotopy' or place coding. Auditory hair cells at the cochlea's base are activated by high-frequency sounds, while those at the apex respond to lower frequencies. Presently, our understanding of tonotopy primarily hinges on electrophysiological, mechanical, and anatomical studies conducted in animals or human cadavers.

Is Characteristic Frequency Limiting Real-Time Electrocochleography During Cochlear Implantation?

Objectives: Electrocochleography (ECochG) recordings during cochlear implantation have shown promise in estimating the impact on residual hearing. The purpose of the study was (1) to determine whether a 250-Hz stimulus is superior to 500-Hz in detecting residual hearing decrement and if so; (2) to evaluate whether crossing the 500-Hz tonotopic, characteristic frequency (CF) place partly explains the problems experienced using 500-Hz.

Design: Multifrequency ECochG comprising an alternating, interleaved acoustic complex of 250- and 500-Hz stimuli was used to elicit cochlear microphonics (CMs) during insertion.

Can Electrocochleography Help Preserve Hearing After Cochlear Implantation With Full Electrode Insertion?

Objectives: To evaluate the utility of intracochlear electrocochleography (ECochG) monitoring during cochlear implant (CI) surgery on postoperative hearing preservation.

Study Design: Prospective, randomized clinical trial.

Setting: Ten high-volume, tertiary care CI centers.

Electrocochleography and cognition are important predictors of speech perception outcomes in noise for cochlear implant recipients.

Although significant progress has been made in understanding outcomes following cochlear implantation, predicting performance remains a challenge. Duration of hearing loss, age at implantation, and electrode positioning within the cochlea together explain ~ 25% of the variability in speech-perception scores in quiet using the cochlear implant (CI). Electrocochleography (ECochG) responses, prior to implantation, account for 47% of the variance in the same speech-perception measures.

Early Hearing Preservation Outcomes Following Cochlear Implantation With New Slim Lateral Wall Electrode Using Electrocochleography.

Objective: Describe early hearing preservation (HP) cochlear implantation (CI) outcomes using a new slim lateral wall electrode (SLWE).

Study Design: Prospective cohort study.

Setting: Tertiary referral center.

Measurements From Ears With Endolymphatic Hydrops and 2-Hydroxypropyl-Beta-Cyclodextrin Provide Evidence That Loudness Recruitment Can Have a Cochlear Origin.

Loudness recruitment is commonly experienced by patients with putative endolymphatic hydrops. Loudness recruitment is abnormal loudness growth with high-level sounds being perceived as having normal loudness even though hearing thresholds are elevated. The traditional interpretation of recruitment is that cochlear amplification has been reduced.

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

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.

Intracochlear Electrocochleography and Speech Perception Scores in Cochlear Implant Recipients.

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 ECochG threshold estimates.

Is cochlear synapse loss an origin of low-frequency hearing loss associated with endolymphatic hydrops?

There is a strong association between endolymphatic hydrops and low-frequency hearing loss, but the origin of the hearing loss remains unknown. A reduction in the number of cochlear afferent synapses between inner hair cells and auditory nerve fibres may be the origin of the low-frequency hearing loss, but this hypothesis has not been directly tested in humans or animals. In humans, measurements of hearing loss and postmortem temporal-bone based measurements of endolymphatic hydrops are generally separated by large amounts of time.