Development of language, cognition and spatial hearing abilities in children with bilateral cochlear implants

AbstractSpatial hearing abilities in children with bilateral cochlear implants (BiCIs) are typically improved when two implants are used compared with a single implant. However, even with BiCIs, spatial hearing is still worse compared to normal-hearing (NH) age-matched children. Here, we focused on children who were younger than three years, hence in their toddler years. Prior research with this age focused on measuring discrimination of sounds from the right versus left.This study measured both discrimination and sound location identification in a nine-alternative forced-choice paradigm using the “reaching for sound” method, whereby children reached for sounding objects as a means of capturing their spatial hearing abilities.Discrimination was measured with sounds randomly presented to the left versus right, and loudspeakers at fixed angles ranging from ±60° to ±15°. On a separate task, sound location identification was measured for locations ranging from ±60° in 15° increments.Thirteen children with BiCIs (27–42 months old) and fifteen age-matched (NH).Discrimination and sound localization were completed for all subjects. For the left–right discrimination task, participants were required to reach a criterion of 4/5 correct trials (80%) at each angular separation prior to beginning the localization task. For sound localization, data was analyzed in two ways. First, percent correct scores were tallied for each participant. Second, for each participant, the root-mean-square-error was calculated to determine the average distance between the response and stimulus, indicative of localization accuracy.All BiCI users were able to discriminate left versus right at angles as small as ±15° when listening with two implants; however, performance was significantly worse when listening with a single implant. All NH toddlers also had >80% correct at ±15°. Sound localization results revealed root-mean-square errors averaging 11.15° in NH toddlers. Children in the BiCI group were generally unable to identify source location on this complex task (average error 37.03°).Although some toddlers with BiCIs are able to localize sound in a manner consistent with NH toddlers, for the majority of toddlers with BiCIs, sound localization abilities are still emerging.

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Spatial hearing in a child with auditory neuropathy spectrum disorder and bilateral cochlear implants

International Journal of Audiology ◽

10.3109/14992027.2013.779755 ◽

2013 ◽

Vol 52 (6) ◽

pp. 400-408 ◽

Cited By ~ 3

Author(s):

Patti M. Johnstone ◽

Kelly R. Yeager ◽

Emily Noss

Keyword(s):

Cochlear Implants ◽

Spatial Hearing ◽

Auditory Neuropathy ◽

Spectrum Disorder ◽

Auditory Neuropathy Spectrum Disorder ◽

Bilateral Cochlear Implants

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Review of recent work on spatial hearing skills in children with bilateral cochlear implants

Cochlear Implants International ◽

10.1179/146701011x13001035752372 ◽

2011 ◽

Vol 12 (sup1) ◽

pp. S30-S34 ◽

Cited By ~ 27

Author(s):

Ruth Y Litovsky

Keyword(s):

Recent Work ◽

Cochlear Implants ◽

Spatial Hearing ◽

Bilateral Cochlear Implants

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

Journal of the American Academy of Audiology ◽

10.3766/jaaa.23.6.9 ◽

2012 ◽

Vol 23 (06) ◽

pp. 476-494 ◽

Cited By ~ 70

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.

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Interaural place-of-stimulation mismatch estimates using CT scans and binaural perception, but not pitch, are consistent in cochlear-implant users

10.1101/2021.02.19.21251930 ◽

2021 ◽

Author(s):

Joshua G. W. Bernstein ◽

Kenneth K. Jensen ◽

Olga A. Stakhovskaya ◽

Jack H. Noble ◽

Michael Hoa ◽

...

Keyword(s):

Cochlear Implants ◽

Interaural Time Difference ◽

Spatial Hearing ◽

Ct Scans ◽

Bilateral Stimulation ◽

Electrode Arrays ◽

Frequency Information ◽

Binaural Processing ◽

Ct Measurements ◽

Hearing Abilities

ABSTRACTBilateral cochlear implants (BI-CIs) or a CI for single-sided deafness (SSD; one normally functioning acoustic ear) can partially restore spatial-hearing abilities including sound localization and speech understanding when there are competing sounds. However for these populations, frequency information is not explicitly aligned across the ears, resulting in interaural place-of-stimulation mismatch. This diminishes spatial-hearing abilities because binaural encoding occurs in interaurally frequency-matched neurons. This study examined whether plasticity – the reorganization of central neural pathways over time – can compensate for peripheral interaural place mismatch. We hypothesized differential plasticity across two systems: none for binaural processing but adaptation toward the frequencies delivered by the specific electrodes for sequential pitch perception. Interaural place mismatch was evaluated in 43 human subjects (20 BI-CI and 23 SSD-CI, both sexes) using interaural-time-difference (ITD) discrimination (simultaneous bilateral stimulation), place-pitch ranking (sequential bilateral stimulation), and physical electrode- location estimates from computed-tomography (CT) scans. On average, CT scans revealed relatively little BI-CI interaural place mismatch (26° insertion-angle mismatch), but relatively large SSD-CI mismatch, particularly at the apical end of the array (166° for an electrode tuned to 300 Hz, decreasing to 14° at 7000 Hz). ITD and CT measurements were in agreement, suggesting little binaural-system plasticity to mismatch. The pitch measurements did not agree with the binaural and CT measurements, suggesting plasticity for pitch encoding or procedural biases. The combined results show that binaural processing may be optimized by using CT-scan information, but not pitch measurements, to program the CI frequency allocation to reduce interaural place mismatch.SIGNIFICANCE STATEMENTPlacement of electrode arrays in users of cochlear implants (CIs; bionic auditory prostheses that partially restore hearing) does not align the frequency information to acoustic neural encoding across the ears. This interaural place-of-stimulation mismatch diminishes spatial hearing abilities. This study shows that for experienced adult CI users with two CIs or with one CI and one normal-hearing ear, the best possible binaural sensitivity occurs when the same cochlear location is stimulated in both ears. This means that binaural brainstem pathways do not experience “plasticity” to compensate for interaural place mismatch – i.e., they do not reorganize to respond to input from different cochlear places. Therefore, explicit correction of interaural place mismatch by a clinician is necessary to derive maximum spatial-hearing benefits.

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Involving Children and Teenagers With Bilateral Cochlear Implants in the Design of the BEARS (Both EARS) Virtual Reality Training Suite Improves Personalization

Frontiers in Digital Health ◽

10.3389/fdgth.2021.759723 ◽

2021 ◽

Vol 3 ◽

Author(s):

Deborah Vickers ◽

Marina Salorio-Corbetto ◽

Sandra Driver ◽

Christine Rocca ◽

Yuli Levtov ◽

...

Keyword(s):

Virtual Reality ◽

Action Research ◽

Young People ◽

Cochlear Implants ◽

Participatory Design ◽

Spatial Hearing ◽

Well Being ◽

Research Protocol ◽

Bilateral Cochlear Implants ◽

Speech In Noise

Older children and teenagers with bilateral cochlear implants often have poor spatial hearing because they cannot fuse sounds from the two ears. This deficit jeopardizes speech and language development, education, and social well-being. The lack of protocols for fitting bilateral cochlear implants and resources for spatial-hearing training contribute to these difficulties. Spatial hearing develops with bilateral experience. A large body of research demonstrates that sound localisation can improve with training, underpinned by plasticity-driven changes in the auditory pathways. Generalizing training to non-trained auditory skills is best achieved by using a multi-modal (audio-visual) implementation and multi-domain training tasks (localisation, speech-in-noise, and spatial music). The goal of this work was to develop a package of virtual-reality games (BEARS, Both EARS) to train spatial hearing in young people (8–16 years) with bilateral cochlear implants using an action-research protocol. The action research protocol used formalized cycles for participants to trial aspects of the BEARS suite, reflect on their experiences, and in turn inform changes in the game implementations. This participatory design used the stakeholder participants as co-creators. The cycles for each of the three domains (localisation, spatial speech-in-noise, and spatial music) were customized to focus on the elements that the stakeholder participants considered important. The participants agreed that the final games were appropriate and ready to be used by patients. The main areas of modification were: the variety of immersive scenarios to cover age range and interests, the number of levels of complexity to ensure small improvements were measurable, feedback, and reward schemes to ensure positive reinforcement, and an additional implementation on an iPad for those who had difficulties with the headsets due to age or balance issues. The effectiveness of the BEARS training suite will be evaluated in a large-scale clinical trial to determine if using the games lead to improvements in speech-in-noise, quality of life, perceived benefit, and cost utility. Such interventions allow patients to take control of their own management reducing the reliance on outpatient-based rehabilitation. For young people, a virtual-reality implementation is more engaging than traditional rehabilitation methods, and the participatory design used here has ensured that the BEARS games are relevant.

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