Current Research with Cochlear Implants at Arizona State University

In this article we review, and discuss the clinical implications of, five projects currently underway in the Cochlear Implant Laboratory at Arizona State University. The projects are (1) norming the AzBio sentence test, (2) comparing the performance of bilateral and bimodal cochlear implant (CI) patients in realistic listening environments, (3) accounting for the benefit provided to bimodal patients by low-frequency acoustic stimulation, (4) assessing localization by bilateral hearing aid patients and the implications of that work for hearing preservation patients, and (5) studying heart rate variability as a possible measure for quantifying the stress of listening via an implant.The long-term goals of the laboratory are to improve the performance of patients fit with cochlear implants and to understand the mechanisms, physiological or electronic, that underlie changes in performance. We began our work with cochlear implant patients in the mid-1980s and received our first grant from the National Institutes of Health (NIH) for work with implanted patients in 1989. Since that date our work with cochlear implant patients has been funded continuously by the NIH. In this report we describe some of the research currently being conducted in our laboratory.

Download Full-text

Impact of Electric Stimulation on Residual Hearing

Journal of the American Academy of Audiology ◽

10.3766/jaaa.15013 ◽

2015 ◽

Vol 26 (08) ◽

pp. 732-740 ◽

Cited By ~ 3

Author(s):

Margaret T. Dillon ◽

Andrea L. Bucker ◽

Marcia C. Adunka ◽

English R. King ◽

Oliver F. Adunka ◽

...

Keyword(s):

Cochlear Implant ◽

Electric Stimulation ◽

Bone Conduction ◽

Low Frequency ◽

Electrode Array ◽

Hearing Preservation ◽

Acoustic Stimulation ◽

First Year ◽

Residual Hearing ◽

Listening Experience

Background: Candidacy criteria for cochlear implantation are expanding to include patients with substantial low-to-mid frequency hearing sensitivity. Postoperative hearing preservation has been achieved in cochlear implant recipients, though with variable outcomes. Previous investigations on postoperative hearing preservation outcomes have evaluated intraoperative procedures. There has been limited review as to whether electric stimulation influences hearing preservation. Purpose: The purpose of this analysis was to evaluate whether charge levels associated with electric stimulation influence postoperative hearing preservation within the first year of listening experience. Research Design: Retrospective analysis of unaided residual hearing and charge levels. Study Sample: Twenty-eight cochlear implant recipients with postoperative residual hearing in the operative ear and at least 12 mo of listening experience with electric-acoustic stimulation (EAS). Data Collection and Analysis: Assessment intervals included initial cochlear implant activation, initial EAS activation, and 3-, 6-, and 12-mo postinitial EAS activation. A masked low-frequency bone-conduction (BC) pure-tone average (PTA) was calculated for all participants at each assessment interval. Charge levels for each electrode were determined using the most comfortable loudness level and pulse width values. Charge levels associated with different regions of the electrode array were compared to the change in the low-frequency BC PTA between two consecutive intervals. Results: Charge levels had little to no association with the postoperative change in low-frequency BC PTA within the first year of listening experience. Conclusions: Electric charge levels do not appear to be reliably related to the subsequent loss of residual low-frequency hearing in the implanted ear within the first year of EAS listening experience.

Download Full-text

Hearing Preservation in Cochlear Implant Surgery

International Journal of Otolaryngology ◽

10.1155/2014/468515 ◽

2014 ◽

Vol 2014 ◽

pp. 1-6 ◽

Cited By ~ 27

Author(s):

Priscila Carvalho Miranda ◽

André Luiz Lopes Sampaio ◽

Rafaela Aquino Fernandes Lopes ◽

Alessandra Ramos Venosa ◽

Carlos Augusto Costa Pires de Oliveira

Keyword(s):

Cochlear Implant ◽

Cochlear Implantation ◽

Surgical Techniques ◽

Low Frequency ◽

Hearing Preservation ◽

Acoustic Stimulation ◽

Electrode Design ◽

High Frequency Region ◽

Electric Acoustic Stimulation ◽

New Treatment

In the past, it was thought that hearing loss patients with residual low-frequency hearing would not be good candidates for cochlear implantation since insertion was expected to induce inner ear trauma. Recent advances in electrode design and surgical techniques have made the preservation of residual low-frequency hearing achievable and desirable. The importance of preserving residual low-frequency hearing cannot be underestimated in light of the added benefit of hearing in noisy atmospheres and in music quality. The concept of electrical and acoustic stimulation involves electrically stimulating the nonfunctional, high-frequency region of the cochlea with a cochlear implant and applying a hearing aid in the low-frequency range. The principle of preserving low-frequency hearing by a “soft surgery” cochlear implantation could also be useful to the population of children who might profit from regenerative hair cell therapy in the future. Main aspects of low-frequency hearing preservation surgery are discussed in this review: its brief history, electrode design, principles and advantages of electric-acoustic stimulation, surgical technique, and further implications of this new treatment possibility for hearing impaired patients.

Download Full-text

Speech Understanding in Complex Listening Environments by Listeners Fit With Cochlear Implants

Journal of Speech Language and Hearing Research ◽

10.1044/2017_jslhr-h-17-0035 ◽

2017 ◽

Vol 60 (10) ◽

pp. 3019-3026 ◽

Cited By ~ 10

Author(s):

Michael F. Dorman ◽

Rene H. Gifford

Keyword(s):

Cochlear Implants ◽

Visual Information ◽

Low Frequency ◽

Hearing Preservation ◽

Point Sources ◽

The Other ◽

Speech Understanding ◽

Sources Of Information ◽

Acoustic Hearing ◽

Listening Environments

PurposeThe aim of this article is to summarize recent published and unpublished research from our 2 laboratories on improving speech understanding in complex listening environments by listeners fit with cochlear implants (CIs).MethodCI listeners were tested in 2 listening environments. One was a simulation of a restaurant with multiple, diffuse noise sources, and the other was a cocktail party with 2 spatially separated point sources of competing speech. At issue was the value of the following sources of information, or interventions, on speech understanding: (a) visual information, (b) adaptive beamformer microphones and remote microphones, (c) bimodal fittings, that is, a CI and contralateral low-frequency acoustic hearing, (d) hearing preservation fittings, that is, a CI with preserved low-frequency acoustic in the same ear plus low-frequency acoustic hearing in the contralateral ear, and (e) bilateral CIs.ResultsA remote microphone provided the largest improvement in speech understanding. Visual information and adaptive beamformers ranked next, while bimodal fittings, bilateral fittings, and hearing preservation provided significant but less benefit than the other interventions or sources of information. Only bilateral CIs allowed listeners high levels of speech understanding when signals were roved over the frontal plane.ConclusionsThe evidence supports the use of bilateral CIs and hearing preservation surgery for best speech understanding in complex environments. These fittings, when combined with visual information and microphone technology, should lead to high levels of speech understanding by CI patients in complex listening environments.Presentation Videohttp://cred.pubs.asha.org/article.aspx?articleid=2601622

Download Full-text

Hearing Preservation Cochlear Implants: A Review of Potential Mechanisms of Hearing Loss After Implantation

Perspectives of the ASHA Special Interest Groups ◽

10.1044/persp2.sig6.54 ◽

2017 ◽

Vol 2 (6) ◽

pp. 54-63

Author(s):

Conor Kelly ◽

Lina A. J. Reiss

Keyword(s):

Hearing Loss ◽

Cochlear Implants ◽

High Frequency ◽

Music Perception ◽

Low Frequency ◽

Lateral Wall ◽

Hearing Preservation ◽

Acoustic Stimulation ◽

Residual Hearing ◽

Wide Range

Hearing preservation cochlear implants (CIs) are specifically designed to preserve residual low-frequency acoustic hearing for use together with electrically stimulated high-frequency hearing. This combined electro-acoustic stimulation (EAS) provides a promising treatment option for patients with severe high-frequency hearing loss, but with some residual low-frequency hearing, and has been shown to improve speech perception, especially in background noise, music perception, and sound source localization. Thus, preservation of residual hearing should be a priority in treatment. Although residual low-frequency hearing is successfully preserved to varying degrees in many patients, some patients experience a loss of residual hearing following implantation. A wide range of potential causes of, or contributors to, loss of residual hearing in EAS CI users have been proposed. In this paper, we review the evidence for several of the proposed causes of hearing loss with EAS CI. We conclude that its etiology is likely a multifactorial, heterogeneous phenomenon. Furthermore, we suggest that studies to further elucidate effects of ischemia on lateral wall function and maintenance of endocochlear potential in the context of EAS CI implantation and use are needed.

Download Full-text

Long-term results of hearing preservation cochlear implant surgery in patients with residual low frequency hearing

Acta Oto-Laryngologica ◽

10.1080/00016489.2016.1252061 ◽

2016 ◽

Vol 137 (5) ◽

pp. 516-521 ◽

Cited By ~ 17

Author(s):

Hideaki Moteki ◽

Shin-ya Nishio ◽

Maiko Miyagawa ◽

Keita Tsukada ◽

Satoshi Iwasaki ◽

...

Keyword(s):

Cochlear Implant ◽

Low Frequency ◽

Hearing Preservation ◽

Long Term Results ◽

Implant Surgery ◽

Cochlear Implant Surgery

Download Full-text

Electric and Acoustic Stimulation in Cochlear Implant Recipients with Hearing Preservation

Seminars in Hearing ◽

10.1055/s-0038-1670707 ◽

2018 ◽

Vol 39 (04) ◽

pp. 414-427 ◽

Cited By ~ 6

Author(s):

Christopher Welch ◽

Margaret Dillon ◽

Harold Pillsbury

Keyword(s):

Hearing Loss ◽

Speech Perception ◽

Cochlear Implant ◽

Hearing Aids ◽

High Frequency ◽

Low Frequency ◽

Hearing Preservation ◽

The United States ◽

Acoustic Stimulation ◽

Electric Hearing

AbstractHearing loss affects 30 million people in the United States, and a subset of these patients have normal low-frequency hearing and ski-sloped high-frequency hearing loss. For these patients, hearing aids alone may not provide adequate benefit. Cochlear implantation alone has been utilized to improve speech perception. The addition of high-frequency electric hearing to low-frequency acoustic hearing in these patients is beneficial. Technical improvements have allowed preservation of low-frequency hearing in cochlear implant recipients, allowing for electric and acoustic stimulation in the same ear with significant improvements in speech perception, sound localization, music appreciation, and quality of life.

Download Full-text

Costs involved in using a cochlear implant in South Africa

South African Journal of Communication Disorders ◽

10.4102/sajcd.v59i1.18 ◽

2012 ◽

Vol 59 (1) ◽

Cited By ~ 1

Author(s):

Gillian Robyn Kerr ◽

Seppo Tuomi ◽

Alida Müller

Keyword(s):

South Africa ◽

Cochlear Implant ◽

Cochlear Implants ◽

Cochlear Implantation ◽

Consumer Price Index ◽

Information Costs ◽

Profound Hearing Loss ◽

Short And Long Term ◽

Implant System

Cochlear implantation is an expensive but effective lifelong intervention for individuals with a severe-to-profound hearing loss. The primary aim of this study was to survey the short- and long-term costs of cochlear implantation. Individuals (N=154) using cochlear implants obtained from the University of Stellenbosch-Tygerberg Hospital Cochlear Implant Unit in Cape Town, South Africa were surveyed using a questionnaire and patient record review. The questionnaire used a combination of closed and open-ended questions to gather both quantitative and qualitative information. Costs were categorised as short- and long-term costs. All costs were converted to constant rands (June 2010) using the Consumer Price Index to allow for comparison in real terms over time. In the first 10 years of implantation the average estimated costs incurred by adults totalled R379 626, and by children R455 225. The initial purchase of the implant system was the most substantial cost, followed by upgrading of the processor. Travel and accommodation costs peaked in the first 2 years. On average the participants spent R2 550 per year on batteries and spares. Rehabilitation for children cost an average of R7 200. Insurance costs averaged R4 040 per year, and processor repairs R3 000 each. In addition to the upfront expense of obtaining the cochlear implant system, individuals using a cochlear implant in South Africa should be prepared for the long-term costs of maintenance, accessing the unit, support services and additional costs associated with use. Knowledge of these costs is important to ensure that individuals are successful users of their cochlear implants in the long term.

Download Full-text

Electro-Natural Stimulation in Partial Deafness Treatment of Adult Cochlear Implant Users: Long-Term Hearing Preservation Results

ORL ◽

10.1159/000497060 ◽

2019 ◽

Vol 81 (2-3) ◽

pp. 63-72 ◽

Cited By ~ 1

Author(s):

Henryk Skarzynski ◽

Artur Lorens ◽

Beata Dziendziel ◽

Joanna J. Rajchel ◽

Monika Matusiak ◽

...

Keyword(s):

Cochlear Implant ◽

Hearing Preservation ◽

Natural Stimulation

Download Full-text

Preservation of residual hearing after cochlear implant surgery with slim modiolar electrode

European Archives of Oto-Rhino-Laryngology ◽

10.1007/s00405-019-05708-x ◽

2019 ◽

Vol 277 (2) ◽

pp. 367-375 ◽

Cited By ~ 2

Author(s):

Matti Iso-Mustajärvi ◽

Sini Sipari ◽

Heikki Löppönen ◽

Aarno Dietz

Keyword(s):

Low Frequency ◽

Hearing Preservation ◽

Acoustic Stimulation ◽

Residual Hearing ◽

Insertion Depth ◽

Cochlear Implant Surgery ◽

Computed Tomography Scans ◽

Electric Acoustic Stimulation ◽

Speech Recognition In Noise

Abstract Purpose To evaluate the insertion results and hearing preservation of a novel slim modiolar electrode (SME) in patients with residual hearing. Methods We retrospectively collected the data from the medical files of 17 patients (18 ears) implanted with a SME. All patients had functional low frequency hearing (PTA (0.125–0.5 kHz) ≤ 80 dB HL). The insertion results were re-examined from the postoperative cone-beam computed tomography scans. Postoperative thresholds were obtained at the time of switch-on of the sound processors (mean 43 days) and at latest follow-up (mean 582 days). The speech recognition in noise was measured with the Finnish matrix sentence test preoperatively and at follow-up. Results The mean insertion depth angle (IDA) was 395°. Neither scala dislocations nor tip fold over were detected. There were no total hearing losses. Functional low-frequency hearing was preserved in 15/18 (83%) ears at switch-on and in 14/17 (82%) ears at follow-up. According to HEARRING classification, 55% (10/18) had complete HP at switch-on and 41% (7/17) still at follow-up. Thirteen patients (14 ears) were initially fitted with electric–acoustic stimulation and seven patients (8 ears) continued to use it after follow-up. Conclusions The preliminary hearing preservation results with the SME were more favorable than reported for other perimodiolar electrodes. The results show that the array may also be feasible for electro-acoustic stimulation; it is beneficial in that it provides adequate cochlear coverage for pure electrical stimulation in the event of postoperative or progressive hearing loss.

Download Full-text