Spatial Hearing and Speech Intelligibility in Bilateral Cochlear Implant Users

Normal hearing listeners have the ability to exploit the audio input perceived by each ear to extract target information in challenging listening scenarios. Bilateral cochlear implant (BiCI) users, however, do not benefit as much as normal hearing listeners do from a bilateral input. In this study, we investigate the effect that bilaterally linked band selection, bilaterally synchronized electrical stimulation and ideal binary masks (IdBMs) have on the ability of 10 BiCIs to understand speech in background noise. The performance was assessed through a sentence-based speech intelligibility test, in a scenario where the speech signal was presented from the front and the interfering noise from one side. The linked band selection relies on the most favorable signal-to-noise-ratio (SNR) ear, which will select the bands to be stimulated for both CIs. Results show that no benefit from adding a second CI to the most favorable SNR side was achieved for any of the tested bilateral conditions. However, when using both devices, speech perception results show that performing linked band selection, besides delivering bilaterally synchronized electrical stimulation, leads to an improvement compared to standard clinical setups. Moreover, the outcomes of this work show that by applying IdBMs, subjects achieve speech intelligibility scores similar to the ones without background noise.

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Speech intelligibility by bilateral cochlear implant users when interaural level cues are made more consistent across frequency

The Journal of the Acoustical Society of America ◽

10.1121/1.4969667 ◽

2016 ◽

Vol 140 (4) ◽

pp. 3099-3099

Author(s):

Christopher Brown

Keyword(s):

Cochlear Implant ◽

Speech Intelligibility ◽

Bilateral Cochlear Implant

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Pinna-Imitating Microphone Directionality Improves Sound Localization and Discrimination in Bilateral Cochlear Implant Users

10.1101/2020.03.05.20023937 ◽

2020 ◽

Cited By ~ 1

Author(s):

Tim Fischer ◽

Christoph Schmid ◽

Martin Kompis ◽

Georgios Mantokoudis ◽

Marco Caversaccio ◽

...

Keyword(s):

Cochlear Implant ◽

Sound Localization ◽

Sound Field ◽

Spatial Hearing ◽

Sound Sources ◽

Static Tests ◽

Tracking Ability ◽

Bilateral Cochlear Implant ◽

Moving Stimulus ◽

The Subject

AbstractObjectivesTo compare the sound-source localization, discrimination and tracking performance of bilateral cochlear implant users with omnidirectional (OMNI) and pinna-imitating (PI) microphone directionality modes.DesignTwelve experienced bilateral cochlear implant users participated in the study. Their audio processors were fitted with two different programs featuring either the OMNI or PI mode. Each subject performed static and dynamic sound field spatial hearing tests in the horizontal plane. The static tests consisted of an absolute sound localization test and a minimum audible angle (MAA) test, which was measured at 8 azimuth directions. Dynamic sound tracking ability was evaluated by the subject correctly indicating the direction of a moving stimulus along two circular paths around the subject.ResultsPI mode led to statistically significant sound localization and discrimination improvements. For static sound localization, the greatest benefit was a reduction in the number of front-back confusions. The front-back confusion rate was reduced from 47% with OMNI mode to 35% with PI mode (p = 0.03). The ability to discriminate sound sources at the sides was only possible with PI mode. The MAA value for the sides decreased from a 75.5 to a 37.7-degree angle when PI mode was used (p < 0.001). Furthermore, a non-significant trend towards an improvement in the ability to track sound sources was observed for both trajectories tested (p = 0.34 and p = 0.27).ConclusionsOur results demonstrate that PI mode can lead to improved spatial hearing performance in bilateral cochlear implant users, mainly as a consequence of improved front-back discrimination with PI mode.

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The Effect of Reducing the Number of Electrodes on Spatial Hearing Tasks for Bilateral Cochlear Implant Recipients

Journal of the American Academy of Audiology ◽

10.3766/jaaa.21.2.5 ◽

2010 ◽

Vol 21 (02) ◽

pp. 110-120 ◽

Cited By ~ 6

Author(s):

Ann Perreau ◽

Richard S. Tyler ◽

Shelley A. Witt

Keyword(s):

Speech Perception ◽

Cochlear Implant ◽

Cochlear Implants ◽

Spatial Hearing ◽

Electrode Arrays ◽

Maximum Performance ◽

Speech Perception In Noise ◽

Spectral Bands ◽

Maximal Performance ◽

Bilateral Cochlear Implant

Background: Many studies have documented the effect of reducing spectral information for speech perception in listeners with normal hearing and hearing impairment. While it is understood that more spectral bands are needed for unilateral cochlear implant listeners to perform well on more challenging listening tasks such as speech perception in noise, it is unclear how reducing the number of spectral bands or electrodes in cochlear implants influences the ability to localize sound or understand speech with spatially separate noise sources. Purpose: The purpose of this study was to measure the effect of reducing the number of electrodes for patients with bilateral cochlear implants on spatial hearing tasks. Research Design: Performance on spatial hearing tasks was examined as the number of bilateral electrodes in the speech processor was deactivated equally across ears and the full frequency spectrum was reallocated to a reduced number of active electrodes. Program parameters (i.e., pulse width, stimulation rate) were held constant among the programs and set identically between the right and left cochlear implants so that only the number of electrodes varied. Study Sample: Nine subjects had used bilateral Nucleus or Advanced Bionics cochlear implants for at least 12 mo prior to beginning the study. Only those subjects with full insertion of the electrode arrays with all electrodes active in both ears were eligible to participate. Data Collection and Analysis: Two test measures were utilized to evaluate the effect of reducing the number of electrodes, including a speech-perception-in-noise test with spatially separated sources and a sound source localization test. Results: Reducing the number of electrodes had different effects across individuals. Three patterns emerged: (1) no effect on localization (two of nine subjects), (2) at least two to four bilateral electrodes were required for maximal performance (five of nine subjects), and (3) performance gradually decreased across conditions as electrode number was reduced (two of nine subjects). For the test of speech perception in spatially separated noise, performance was affected as the number of electrodes was reduced for all subjects. Two categories of performance were found: (1) at least three or four bilateral electrodes were needed for maximum performance (five of seven subjects) and (2) as the number of electrodes were reduced, performance gradually decreased across conditions (two of seven subjects). Conclusion: Large individual differences exist in determining maximum performance using bilateral electrodes for localization and speech perception in noise. For some bilateral cochlear implant users, as few as three to four electrodes can be used to obtain maximal performance on localization and speech-in-noise tests. However, other listeners show a gradual decrement in performance on both tasks when the number of electrodes is reduced.

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Effects of temporal fine structure preservation on spatial hearing in bilateral cochlear implant users

The Journal of the Acoustical Society of America ◽

10.1121/10.0005732 ◽

2021 ◽

Vol 150 (2) ◽

pp. 673-686

Author(s):

T. Fischer ◽

C. Schmid ◽

M. Kompis ◽

G. Mantokoudis ◽

M. Caversaccio ◽

...

Keyword(s):

Fine Structure ◽

Cochlear Implant ◽

Spatial Hearing ◽

Temporal Fine Structure ◽

Structure Preservation ◽

Bilateral Cochlear Implant ◽

Fine Structure Preservation

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Spatial Hearing Difficulties in Reaching Space in Bilateral Cochlear Implant Children Improve With Head Movements

Ear and Hearing ◽

10.1097/aud.0000000000001090 ◽

2021 ◽

Vol Publish Ahead of Print ◽

Author(s):

Aurélie Coudert ◽

Valérie Gaveau ◽

Julie Gatel ◽

Grégoire Verdelet ◽

Romeo Salemme ◽

...

Keyword(s):

Cochlear Implant ◽

Spatial Hearing ◽

Head Movements ◽

Bilateral Cochlear Implant ◽

Hearing Difficulties

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