The Impact of Synchronized Cochlear Implant Sampling and Stimulation on Free-Field Spatial Hearing Outcomes

2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Stephen R. Dennison ◽  
Heath G. Jones ◽  
Alan Kan ◽  
Ruth Y. Litovsky
Keyword(s):  
Cochlear Implant ◽  
Free Field ◽  
Spatial Hearing ◽  
Hearing Outcomes ◽  
The Impact

scholarly journals Studies on Bilateral Cochlear Implants at the University of Wisconsin’s Binaural Hearing and Speech Laboratory

2012 ◽  
Vol 23 (06) ◽  
pp. 476-494 ◽  
Author(s):  
Ruth Y. Litovsky ◽  
Matthew J. Goupell ◽  
Shelly Godar ◽  
Tina Grieco-Calub ◽  
Gary L. Jones ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Age At Onset ◽  
Free Field ◽  
Spatial Hearing ◽  
Binaural Hearing ◽  
Systematic Investigation ◽  
Spatial Cues ◽  
Bilateral Cochlear Implants ◽  
Adults And Children ◽  
The Impact

This report highlights research projects relevant to binaural and spatial hearing in adults and children. In the past decade we have made progress in understanding the impact of bilateral cochlear implants (BiCIs) on performance in adults and children. However, BiCI users typically do not perform as well as normal hearing (NH) listeners. In this article we describe the benefits from BiCIs compared with a single cochlear implant (CI), focusing on measures of spatial hearing and speech understanding in noise. We highlight the fact that in BiCI listening the devices in the two ears are not coordinated; thus binaural spatial cues that are available to NH listeners are not available to BiCI users. Through the use of research processors that carefully control the stimulus delivered to each electrode in each ear, we are able to preserve binaural cues and deliver them with fidelity to BiCI users. Results from those studies are discussed as well, with a focus on the effect of age at onset of deafness and plasticity of binaural sensitivity. Our work with children has expanded both in number of subjects tested and age range included. We have now tested dozens of children ranging in age from 2 to 14 yr. Our findings suggest that spatial hearing abilities emerge with bilateral experience. While we originally focused on studying performance in free field, where real world listening experiments are conducted, more recently we have begun to conduct studies under carefully controlled binaural stimulation conditions with children as well. We have also studied language acquisition and speech perception and production in young CI users. Finally, a running theme of this research program is the systematic investigation of the numerous factors that contribute to spatial and binaural hearing in BiCI users. By using CI simulations (with vocoders) and studying NH listeners under degraded listening conditions, we are able to tease apart limitations due to the hardware/software of the CI systems from limitations due to neural pathology.

Impact of Cochlear Implantation on Neurocognitive Subdomains in Adult Cochlear Implant Recipients

2021 ◽  
pp. 1-10
Author(s):  
Christiane Völter ◽  
Lisa Götze ◽  
Imme Haubitz ◽  
Janine Müther ◽  
Stefan Dazert ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Verbal Fluency ◽  
Homogeneous Population ◽  
Delayed Recall ◽  
Hearing Status ◽  
Age Related ◽  
Significant Difference ◽  
The Impact

<b><i>Introduction:</i></b> Age-related hearing loss affects about one-third of the population worldwide. Studies suggest that hearing loss may be linked to cognitive decline and auditory rehabilitation may improve cognitive functions. So far, the data are limited, and the underlying mechanisms are not fully understood. The study aimed to analyze the impact of cochlear implantation on cognition in a large homogeneous population of hearing-impaired adults using a comprehensive non-auditory cognitive assessment with regard to normal-hearing (NH) subjects. <b><i>Material and Methods:</i></b> Seventy-one cochlear implant (CI) candidates with a postlingual, bilateral severe or profound hearing loss aged 66.3 years (standard deviation [SD] 9.2) and 105 NH subjects aged 65.96 years (SD 9.4) were enrolled. The computer-based neurocognitive tool applied included 11 subtests covering attention (M3), short- and long-term memory (recall and delayed recall), working memory (0- and 2-back, Operation Span [OSPAN] task), processing speed (Trail Making Test [TMT] A), mental flexibility (TMT B), inhibition (cFlanker and iFlanker), and verbal fluency. CI patients underwent a neurocognitive testing preoperatively as well as 12 months postoperatively. Impact of hearing status, age, gender, and education on cognitive subdomains was studied. Additionally, after controlling for education and age, cognitive performance of CI subjects (<i>n</i> = 41) was compared to that of NH (<i>n</i> = 34). <b><i>Results:</i></b> CI users achieved significantly better neurocognitive scores 12 months after cochlear implantation than before in most subtests (M3, [delayed] recall, 2-back, OSPAN, iFlanker, and verbal fluency; all <i>p</i> &#x3c; 0.05) except for the TMT A and B. A significant correlation could be found between the postoperative improvement in speech perception and in the attentional task M3 (<i>p</i> = 0.01). Hearing status (<i>p</i> = 0.0006) had the strongest effect on attention, whereas education had a high impact on recall (<i>p</i> = 0.002), OSPAN (<i>p</i> = 0.0004), and TMT A (<i>p</i> = 0.005) and B (<i>p</i> = 0.003). Inhibition was mainly age-dependent with better results in younger subjects (<i>p</i> = 0.016). Verbal fluency was predicted by gender as females outperformed men (<i>p</i> = 0.009). Even after controlling for age and education NH subjects showed a significantly better performance than CI candidates in the recall (<i>p</i> = 0.03) and delayed recall (<i>p</i> = 0.01) tasks. Postoperatively, there was no significant difference between the 2 groups anymore. <b><i>Conclusion:</i></b> Impact of cochlear implantation on neurocognitive functions differs according to the cognitive subdomains. Postoperatively, CI recipients performed as good as age- and education-matched NH subjects.

The Impact of Comorbidities in the Aging Population on Cochlear Implant Outcomes

2017 ◽  
Vol 38 (8) ◽  
pp. e285-e288 ◽  
Author(s):  
Brent Jerome Wilkerson ◽  
Sandra F. Porps ◽  
Seilesh C. Babu
Keyword(s):  
Cochlear Implant ◽  
Aging Population ◽  
The Impact

scholarly journals Surgical Results of Retrograde Mastoidectomy with Primary Reconstruction of the Ear Canal and Mastoid Cavity

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Chao-Yin Kuo ◽  
Bor-Rong Huang ◽  
Hsin-Chien Chen ◽  
Cheng-Ping Shih ◽  
Wei-Kang Chang ◽  
...  
Keyword(s):  
Adverse Events ◽  
Mastoid Cavity ◽  
Surgical Results ◽  
Ear Canal ◽  
Hearing Results ◽  
Hearing Gain ◽  
Before And After ◽  
Hearing Outcomes ◽  
The Impact

The aim of this study was to retrospectively review the long-term hearing results and the impact of mastoid exclusion/obliteration in patients with cholesteatoma (102 ears) who underwent retrograde tympanomastoidectomy and in whom bone chips/paté were applied as the sole materials during the procedure. In 79 ears, this was combined with ossiculoplasty in a single-stage procedure. In >71% of ears, the results of audiometric testing were monitored for more than 2 years. The results suggested there was a significant gain in hearing following surgery, with respect to the postoperative change in both air-conduction thresholds and air-bone gaps (P<0.001). Linear regression analyses of pure-tone averages at different frequencies, before and after surgery, demonstrated that patients benefitted from a postoperative hearing gain at low and middle frequencies, but their hearing often deteriorated at frequencies of 8000 Hz. As for the impact of the type of tympanoplasty on hearing outcomes, type III-interposition markedly increased hearing gain. The overall rate of postoperative adverse events was 8.8%. We conclude that reconstruction of the ear canal and mastoid via mastoid exclusion/obliteration using bone chips/paté can be considered as an alternative procedure following retrograde mastoidectomy. It gives excellent surgical results and has fewer postoperative adverse events.

Saliency of Vowel Features in Neural Responses of Cochlear Implant Users

2018 ◽  
Vol 49 (6) ◽  
pp. 388-397
Author(s):  
François Prévost ◽  
Alexandre Lehmann
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Fundamental Frequency ◽  
Mismatch Negativity ◽  
Free Field ◽  
Event Related Potentials ◽  
Oddball Paradigm ◽  
Aural Rehabilitation ◽  
Spectral Components ◽  
Related Potentials

Cochlear implants restore hearing in deaf individuals, but speech perception remains challenging. Poor discrimination of spectral components is thought to account for limitations of speech recognition in cochlear implant users. We investigated how combined variations of spectral components along two orthogonal dimensions can maximize neural discrimination between two vowels, as measured by mismatch negativity. Adult cochlear implant users and matched normal-hearing listeners underwent electroencephalographic event-related potentials recordings in an optimum-1 oddball paradigm. A standard /a/ vowel was delivered in an acoustic free field along with stimuli having a deviant fundamental frequency (+3 and +6 semitones), a deviant first formant making it a /i/ vowel or combined deviant fundamental frequency and first formant (+3 and +6 semitones /i/ vowels). Speech recognition was assessed with a word repetition task. An analysis of variance between both amplitude and latency of mismatch negativity elicited by each deviant vowel was performed. The strength of correlations between these parameters of mismatch negativity and speech recognition as well as participants’ age was assessed. Amplitude of mismatch negativity was weaker in cochlear implant users but was maximized by variations of vowels’ first formant. Latency of mismatch negativity was later in cochlear implant users and was particularly extended by variations of the fundamental frequency. Speech recognition correlated with parameters of mismatch negativity elicited by the specific variation of the first formant. This nonlinear effect of acoustic parameters on neural discrimination of vowels has implications for implant processor programming and aural rehabilitation.

Amount of Frequency Compression in Bimodal Cochlear Implant Users Is a Poor Predictor for Audibility and Spatial Hearing

2021 ◽  
pp. 1-14
Author(s):  
Snandan Sharma ◽  
Waldo Nogueira ◽  
A. John van Opstal ◽  
Josef Chalupper ◽  
Lucas H. M. Mens ◽  
...  
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Sound Localization ◽  
High Frequency ◽  
Hearing Aid ◽  
Spatial Hearing ◽  
Meaningful Improvement ◽  
Frequency Compression ◽  
Knee Point ◽  
Localization Performance

Purpose Speech understanding in noise and horizontal sound localization is poor in most cochlear implant (CI) users with a hearing aid (bimodal stimulation). This study investigated the effect of static and less-extreme adaptive frequency compression in hearing aids on spatial hearing. By means of frequency compression, we aimed to restore high-frequency audibility, and thus improve sound localization and spatial speech recognition. Method Sound-detection thresholds, sound localization, and spatial speech recognition were measured in eight bimodal CI users, with and without frequency compression. We tested two compression algorithms: a static algorithm, which compressed frequencies beyond the compression knee point (160 or 480 Hz), and an adaptive algorithm, which aimed to compress only consonants leaving vowels unaffected (adaptive knee-point frequencies from 736 to 2946 Hz). Results Compression yielded a strong audibility benefit (high-frequency thresholds improved by 40 and 24 dB for static and adaptive compression, respectively), no meaningful improvement in localization performance (errors remained > 30 deg), and spatial speech recognition across all participants. Localization biases without compression (toward the hearing-aid and implant side for low- and high-frequency sounds, respectively) disappeared or reversed with compression. The audibility benefits provided to each bimodal user partially explained any individual improvements in localization performance; shifts in bias; and, for six out of eight participants, benefits in spatial speech recognition. Conclusions We speculate that limiting factors such as a persistent hearing asymmetry and mismatch in spectral overlap prevent compression in bimodal users from improving sound localization. Therefore, the benefit in spatial release from masking by compression is likely due to a shift of attention to the ear with the better signal-to-noise ratio facilitated by compression, rather than an improved spatial selectivity. Supplemental Material https://doi.org/10.23641/asha.16869485

Evaluating the Long-Term Hearing Outcomes of Cochlear Implant Users With Single-Sided Deafness

2019 ◽  
Vol 40 (6) ◽  
pp. e575-e580 ◽  
Author(s):  
Dayse Távora-Vieira ◽  
Gunesh P. Rajan ◽  
Paul Van de Heyning ◽  
Griet Mertens
Keyword(s):  
Cochlear Implant ◽  
Single Sided Deafness ◽  
Hearing Outcomes

BalanCI: Head-Referenced Cochlear Implant Stimulation Improves Balance in Children with Bilateral Cochleovestibular Loss

2019 ◽  
Vol 25 (Suppl. 1-2) ◽  
pp. 60-71 ◽  
Author(s):  
Nikolaus E. Wolter ◽  
Karen A. Gordon ◽  
Jennifer L. Campos ◽  
Luis D. Vilchez Madrigal ◽  
David D. Pothier ◽  
...  
Keyword(s):  
Postural Control ◽  
Cochlear Implant ◽  
Virtual Environment ◽  
Clinical Setting ◽  
Spatial Information ◽  
Center Of Pressure ◽  
Effective Means ◽  
Sensory Information ◽  
Clinical Test ◽  
The Impact

Introduction: To determine the impact of a head-referenced cochlear implant (CI) stimulation system, BalanCI, on balance and postural control in children with bilateral cochleovestibular loss (BCVL) who use bilateral CI. Methods: Prospective, blinded case-control study. Balance and postural control testing occurred in two settings: (1) quiet clinical setting and (2) immersive realistic virtual environment (Challenging Environment Assessment Laboratory [CEAL], Toronto Rehabilitation Institute). Postural control was assessed in 16 and balance in 10 children with BCVL who use bilateral CI, along with 10 typically developing children. Children with neuromotor, cognitive, or visual deficits that would prevent them from performing the tests were excluded. Children wore the BalanCI, which is a head-mounted device that couples with their CIs through the audio port and provides head-referenced spatial information delivered via the intracochlear electrode array. Postural control was measured by center of pressure (COP) and time to fall using the WiiTM (Nintendo, WA, USA) Balance Board for feet and the BalanCI for head, during the administration of the Modified Clinical Test of Sensory Interaction in Balance (CTSIB-M). The COP of the head and feet were assessed for change by deviation, measured as root mean square around the COP (COP-RMS), rate of deviation (COP-RMS/duration), and rate of path length change from center (COP-velocity). Balance was assessed by the Bruininks-Oseretsky Test of Motor Proficiency 2, balance subtest (BOT-2), specifically, BOT-2 score as well as time to fall/fault. Results: In the virtual environment, children demonstrated more stable balance when using BalanCI as measured by an improvement in BOT-2 scores. In a quiet clinical setting, the use of BalanCI led to improved postural control as demonstrated by significant reductions in COP-RMS and COP-velocity. With the use of BalanCI, the number of falls/faults was significantly reduced and time to fall increased. Conclusions: BalanCI is a simple and effective means of improving postural control and balance in children with BCVL who use bilateral CI. BalanCI could potentially improve the safety of these children, reduce the effort they expend maintaining balance and allow them to take part in more complex balance tasks where sensory information may be limited and/or noisy.

THE IMPACT OF AUDITORY NERVE EXPERIMENTS ON COCHLEAR IMPLANT DESIGN

1983 ◽  
Vol 405 (1 Cochlear Pros) ◽  
pp. 114-121 ◽  
Author(s):  
N. Y. S. Kiang ◽  
E. M. Keithley ◽  
M. C. Liberman
Keyword(s):  
Cochlear Implant ◽  
Auditory Nerve ◽  
Implant Design ◽  
The Impact
Sign in / Sign up

Export Citation Format

Share Document