scholarly journals Residual Hearing Affects Contralateral Routing of Signals in Cochlear Implant Users

2021 ◽  
pp. 1-8
Author(s):  
H. Christiaan Stronks ◽  
Jeroen J. Briaire ◽  
Johan H.M. Frijns
Keyword(s):  
Cochlear Implant ◽  
Free Field ◽  
Target Population ◽  
Residual Hearing ◽  
Primary Target ◽  
Shadow Effect ◽  
Speech Reception ◽  
Spatial Configurations ◽  
Potential Disadvantage ◽  
Contralateral Ear

<b><i>Introduction:</i></b> Contralateral routing of signals (CROS) can be used to eliminate the head shadow effect. In unilateral cochlear implant (CI) users, CROS can be achieved with placement of a microphone on the contralateral ear, with the signal streamed to the CI ear. CROS was originally developed for unilateral CI users without any residual hearing in the nonimplanted ear. However, the criteria for implantation are becoming progressively looser, and the nonimplanted ear can have substantial residual hearing. In this study, we assessed how residual hearing in the contralateral ear influences CROS effectiveness in unilateral CI users. <b><i>Methods:</i></b> In a group of unilateral CI users (<i>N</i> = 17) with varying amounts of residual hearing, we deployed free-field speech tests to determine the effects of CROS on the speech reception threshold (SRT) in amplitude-modulated noise. We compared 2 spatial configurations: (1) speech presented to the CROS ear and noise to the CI ear (S<sub>CROS</sub>N<sub>CI</sub>) and (2) the reverse (S<sub>CI</sub>N<sub>CROS</sub>). <b><i>Results:</i></b> Compared with the use of CI only, CROS improved the SRT by 6.4 dB on average in the S<sub>CROS</sub>N<sub>CI</sub> configuration. In the S<sub>CI</sub>N<sub>CROS</sub> configuration, however, CROS deteriorated the SRT by 8.4 dB. The benefit and disadvantage of CROS both decreased significantly with the amount of residual hearing. <b><i>Conclusion:</i></b> CROS users need careful instructions about the potential disadvantage when listening in conditions where the CROS ear mainly receives noise, especially if they have residual hearing in the contralateral ear. The CROS device should be turned off when it is on the noise side (S<sub>CI</sub>N<sub>CROS</sub>). CI users with residual hearing in the CROS ear also should understand that contralateral amplification (i.e., a bimodal hearing solution) will yield better results than a CROS device. Unilateral CI users with no functional contralateral hearing should be considered the primary target population for a CROS device.

scholarly journals Effectiveness and efficiency of a dedicated bimodal fitting formula

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Domenico Cuda ◽  
Alessandra Murri ◽  
Anna Mainardi ◽  
Josef Chalupper
Keyword(s):  
Cochlear Implant ◽  
Speech Intelligibility ◽  
Hearing Aid ◽  
Sound Quality ◽  
Residual Hearing ◽  
Listening Effort ◽  
Subject Specific ◽  
Contralateral Ear ◽  
Effectiveness And Efficiency ◽  
Localization Ability

The population of unilateral cochlear implant (CI) users with aidable residual hearing in the contralateral ear is continuously growing. Aiding the contralateral ear with a hearing aid has been shown to provide substantial benefit regarding speech intelligibility in quiet and in noise, sound quality, localization ability and listening effort. In this study, a dedicated hearing aid with the accompanying fitting prescription, tailored to the needs of bimodal listeners was evaluated in nine bimodal CI users. Speech intelligibility scores in noise revealed on-par performance of the dedicated bimodal fitting compared to the clinical standard prescription. 78% of the bimodal CI users preferred the dedicated bimodal fitting over the clinical standard. The minimal subject-specific finetuning effort required during the dedicated bimodal fitting process emphasizes the clinical efficiency.

Perceptual Learning of Vocoded Speech With and Without Contralateral Hearing: Implications for Cochlear Implant Rehabilitation

2020 ◽  
pp. 1-10
Author(s):  
Martin Chavant ◽  
Alexis Hervais-Adelman ◽  
Olivier Macherey
Keyword(s):  
Cochlear Implant ◽  
Perceptual Learning ◽  
Speech Signal ◽  
Training Phase ◽  
Monosyllabic Words ◽  
Low Pass ◽  
Contralateral Ear ◽  
Number Of Individuals ◽  
Insight Into ◽  
Vocoded Speech

Purpose An increasing number of individuals with residual or even normal contralateral hearing are being considered for cochlear implantation. It remains unknown whether the presence of contralateral hearing is beneficial or detrimental to their perceptual learning of cochlear implant (CI)–processed speech. The aim of this experiment was to provide a first insight into this question using acoustic simulations of CI processing. Method Sixty normal-hearing listeners took part in an auditory perceptual learning experiment. Each subject was randomly assigned to one of three groups of 20 referred to as NORMAL, LOWPASS, and NOTHING. The experiment consisted of two test phases separated by a training phase. In the test phases, all subjects were tested on recognition of monosyllabic words passed through a six-channel “PSHC” vocoder presented to a single ear. In the training phase, which consisted of listening to a 25-min audio book, all subjects were also presented with the same vocoded speech in one ear but the signal they received in their other ear differed across groups. The NORMAL group was presented with the unprocessed speech signal, the LOWPASS group with a low-pass filtered version of the speech signal, and the NOTHING group with no sound at all. Results The improvement in speech scores following training was significantly smaller for the NORMAL than for the LOWPASS and NOTHING groups. Conclusions This study suggests that the presentation of normal speech in the contralateral ear reduces or slows down perceptual learning of vocoded speech but that an unintelligible low-pass filtered contralateral signal does not have this effect. Potential implications for the rehabilitation of CI patients with partial or full contralateral hearing are discussed.

scholarly journals In Situ 3D-Imaging of the Inner Ear Synapses with a Cochlear Implant

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 301
Author(s):  
Kathrin Malfeld ◽  
Nina Armbrecht ◽  
Holger A. Volk ◽  
Thomas Lenarz ◽  
Verena Scheper
Keyword(s):  
Cochlear Implant ◽  
Inner Ear ◽  
Laser Scanning ◽  
3D Imaging ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Sensory Cells ◽  
Residual Hearing ◽  
Preparation Methods

In recent years sensorineural hearing loss was found to affect not exclusively, nor at first, the sensory cells of the inner ear. The sensory cells’ synapses and subsequent neurites are initially damaged. Auditory synaptopathies also play an important role in cochlear implant (CI) care, as they can lead to a loss of physiological hearing in patients with residual hearing. These auditory synaptopathies and in general the cascades of hearing pathologies have been in the focus of research in recent years with the aim to develop more targeted and individually tailored therapeutics. In the current study, a method to examine implanted inner ears of guinea pigs was developed to examine the synapse level. For this purpose, the cochlea is made transparent and scanned with the implant in situ using confocal laser scanning microscopy. Three different preparation methods were compared to enable both an overview image of the cochlea for assessing the CI position and images of the synapses on the same specimen. The best results were achieved by dissection of the bony capsule of the cochlea.

Comparing the Effect of Different Hearing Aid Fitting Methods in Bimodal Cochlear Implant Users

2019 ◽  
Vol 28 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jantien L. Vroegop ◽  
J. Gertjan Dingemanse ◽  
Marc P. van der Schroeff ◽  
André Goedegebure
Keyword(s):  
Cochlear Implant ◽  
Sound Localization ◽  
Hearing Aid ◽  
Hearing Aid Fitting ◽  
Speech In Noise ◽  
Localization Test ◽  
Fitting Procedures ◽  
Auditory Performance ◽  
Contralateral Ear ◽  
Noise Test

PurposeThe aim of the study was to investigate the effect of 3 hearing aid fitting procedures on provided gain of the hearing aid in bimodal cochlear implant users and their effect on bimodal benefit.MethodThis prospective study measured hearing aid gain and auditory performance in a cross-over design in which 3 hearing aid fitting methods were compared. Hearing aid fitting methods differed in initial gain prescription rule (NAL-NL2 and Audiogram+) and loudness balancing method (broadband vs. narrowband loudness balancing). Auditory functioning was evaluated by a speech-in-quiet test, a speech-in-noise test, and a sound localization test. Fourteen postlingually deafened adult bimodal cochlear implant users participated in the study.ResultsNo differences in provided gain and in bimodal performance were found for the different hearing aid fittings. For all hearing aid fittings, a bimodal benefit was found for speech in noise and sound localization.ConclusionOur results confirm that cochlear implant users with residual hearing in the contralateral ear substantially benefit from bimodal stimulation. However, on average, no differences were found between different types of fitting methods, varying in prescription rule and loudness balancing method.

scholarly journals Self-Assessment of Unilateral and Bimodal Cochlear Implant Experiences in Daily Life

2020 ◽  
Author(s):  
Elke M J Devocht ◽  
A. Miranda L Janssen ◽  
Josef Chalupper ◽  
Robert J Stokroos ◽  
Herman Kingma ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Cochlear Implant ◽  
Daily Life ◽  
Subjective Experiences ◽  
Self Assessment ◽  
Hearing Ability ◽  
Hearing Handicap ◽  
General Quality ◽  
Contralateral Ear

AbstractObjectiveThe subjective experiences were assessed of cochlear implant (CI) users either wearing or not wearing a hearing aid (HA) at the contralateral ear.DesignUnilateral CI-recipients were asked to fill out a set of daily-life questionnaires on bimodal HA use, hearing disability, hearing handicap and general quality of life.Study sampleTwenty-six CI-recipients who regularly use a contralateral HA (bimodal group) and twenty-two CI-recipients who do not use a HA in the contralateral ear (unilateral group).ResultsComparisons between both groups (bimodal versus unilateral) showed no difference in self-rated disability, hearing handicap or general quality of life. However within the group of bimodal listeners, participants did report a significant benefit of bimodal hearing ability in various daily life listening situations.ConclusionsBimodal benefit in daily life can consistently be experienced and reported within the group of bimodal users.

Electrocochleography in Cochlear Implant Recipients With Residual Hearing

2017 ◽  
Vol 38 (3) ◽  
pp. e161-e167 ◽  
Author(s):  
Kanthaiah Koka ◽  
Aniket A. Saoji ◽  
Leonid M. Litvak
Keyword(s):  
Cochlear Implant ◽  
Residual Hearing
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