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.

scholarly journals Evaluating the Impact of Age, Acoustic Exposure, and Electrical Stimulation on Binaural Sensitivity in Adult Bilateral Cochlear Implant Patients

2020 ◽  
Vol 10 (6) ◽  
pp. 406
Author(s):  
Tanvi Thakkar ◽  
Sean R. Anderson ◽  
Alan Kan ◽  
Ruth Y. Litovsky
Keyword(s):  
Hearing Impairment ◽  
Age At Onset ◽  
Spatial Cues ◽  
Related Factors ◽  
Bilateral Cochlear Implants ◽  
Electric Hearing ◽  
Younger Age ◽  
Bilateral Cochlear Implant ◽  
Acoustic Exposure ◽  
The Impact

Deafness in both ears is highly disruptive to communication in everyday listening situations. Many individuals with profound deafness receive bilateral cochlear implants (CIs) to gain access to spatial cues used in localization and speech understanding in noise. However, the benefit of bilateral CIs, in particular sensitivity to interaural time and level differences (ITD and ILDs), varies among patients. We measured binaural sensitivity in 46 adult bilateral CI patients to explore the relationship between binaural sensitivity and three classes of patient-related factors: age, acoustic exposure, and electric hearing experience. Results show that ILD sensitivity increased with shorter years of acoustic exposure, younger age at testing, or an interaction between these factors, moderated by the duration of bilateral hearing impairment. ITD sensitivity was impacted by a moderating effect between years of bilateral hearing impairment and CI experience. When age at onset of deafness was treated as two categories (<18 vs. >18 years of age), there was no clear effect for ILD sensitivity, but some differences were observed for ITD sensitivity. Our findings imply that maximal binaural sensitivity is obtained by listeners with a shorter bilateral hearing impairment, a longer duration of CI experience, and potentially a younger age at testing. 198/200.

scholarly journals Auditory Attention and Spatial Unmasking in Children With Cochlear Implants

2020 ◽  
Vol 24 ◽  
pp. 233121652094698
Author(s):  
Sara M. Misurelli ◽  
Matthew J. Goupell ◽  
Emily A. Burg ◽  
Rachael Jocewicz ◽  
Alan Kan ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Free Field ◽  
Auditory Attention ◽  
Noisy Environments ◽  
Speech Stimuli ◽  
Bilateral Cochlear Implants ◽  
Speech Reception ◽  
Spatial Unmasking ◽  
Speech Reception Thresholds ◽  
Hearing Children

The ability to attend to target speech in background noise is an important skill, particularly for children who spend many hours in noisy environments. Intelligibility improves as a result of spatial or binaural unmasking in the free-field for normal-hearing children; however, children who use bilateral cochlear implants (BiCIs) demonstrate little benefit in similar situations. It was hypothesized that poor auditory attention abilities might explain the lack of unmasking observed in children with BiCIs. Target and interferer speech stimuli were presented to either or both ears of BiCI participants via their clinical processors. Speech reception thresholds remained low when the target and interferer were in opposite ears, but they did not show binaural unmasking when the interferer was presented to both ears and the target only to one ear. These results demonstrate that, in the most extreme cases of stimulus separation, children with BiCIs can ignore an interferer and attend to target speech, but there is weak or absent binaural unmasking. It appears that children with BiCIs mostly experience poor encoding of binaural cues rather than deficits in ability to selectively attend to target speech.

scholarly journals Sound Localization in Toddlers with Normal Hearing and with Bilateral Cochlear Implants Revealed Through a Novel “Reaching for Sound” Task

2020 ◽  
Vol 31 (03) ◽  
pp. 195-208 ◽  
Author(s):  
Erica E. Bennett ◽  
Ruth Y. Litovsky
Keyword(s):  
Cochlear Implants ◽  
Root Mean Square ◽  
Sound Localization ◽  
Spatial Hearing ◽  
Normal Hearing ◽  
Mean Square ◽  
Sound Location ◽  
Bilateral Cochlear Implants ◽  
Single Implant ◽  
Hearing Abilities

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.

scholarly journals Bilateral Cochlear Implants in Adults and Children

2004 ◽  
Vol 130 (5) ◽  
pp. 648 ◽  
Author(s):  
Ruth Y. Litovsky ◽  
Aaron Parkinson ◽  
Jennifer Arcaroli ◽  
Robert Peters ◽  
Jennifer Lake ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Bilateral Cochlear Implants ◽  
Adults And Children

scholarly journals Superhuman spatial hearing technology for ultrasonic frequencies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ville Pulkki ◽  
Leo McCormack ◽  
Raimundo Gonzalez
Keyword(s):  
Sound Field ◽  
Spatial Hearing ◽  
Digital Signal ◽  
Binaural Hearing ◽  
Spatial Cues ◽  
Ultrasonic Signals ◽  
Ultrasonic Sound ◽  
Spatial Parameters ◽  
Processing Techniques ◽  
New Applications

AbstractUltrasonic sources are inaudible to humans, and while digital signal processing techniques are available to bring ultrasonic signals into the audible range, there are currently no systems which also simultaneously permit the listener to localise the sources through spatial hearing. Therefore, we describe a method whereby an in-situ listener with normal binaural hearing can localise ultrasonic sources in real-time; opening-up new applications, such as the monitoring of certain forms of wild life in their habitats and man-made systems. In this work, an array of ultrasonic microphones is mounted to headphones, and the spatial parameters of the ultrasonic sound-field are extracted. A pitch-shifted signal is then rendered to the headphones with spatial properties dictated by the estimated parameters. The processing provides the listener with the spatial cues that would normally occur if the acoustic wave produced by the source were to arrive at the listener having already been pitch-shifted. The results show that the localisation accuracy delivered by the proof-of-concept device implemented here is almost as good as with audible sources, as tested both in the laboratory and under conditions in the field.

scholarly journals Functional Consequences of Poor Binaural Hearing in Development: Evidence From Children With Unilateral Hearing Loss and Children Receiving Bilateral Cochlear Implants

2021 ◽  
Vol 25 ◽  
pp. 233121652110512
Author(s):  
Claire McSweeny ◽  
Sharon L. Cushing ◽  
Jennifer L. Campos ◽  
Blake C. Papsin ◽  
Karen A. Gordon
Keyword(s):  
Hearing Loss ◽  
Speech Perception ◽  
Cochlear Implants ◽  
Verbal Memory ◽  
Binaural Hearing ◽  
Normal Hearing ◽  
Unilateral Hearing Loss ◽  
Visuospatial Memory ◽  
Bilateral Cochlear Implants ◽  
Academic Deficits

Poor binaural hearing in children was hypothesized to contribute to related cognitive and academic deficits. Children with unilateral hearing have normal hearing in one ear but no access to binaural cues. Their cognitive and academic deficits could be unique from children receiving bilateral cochlear implants (CIs) at young ages who have poor access to spectral cues and impaired binaural sensitivity. Both groups are at risk for vestibular/balance deficits which could further contribute to memory and learning challenges. Eighty-eight children (43 male:45 female, aged 9.89  ±  3.40 years), grouped by unilateral hearing loss ( n = 20), bilateral CI ( n = 32), and typically developing ( n = 36), completed a battery of sensory, cognitive, and academic tests. Analyses revealed that children in both hearing loss groups had significantly poorer skills (accounting for age) on most tests than their normal hearing peers. Children with unilateral hearing loss had more asymmetric speech perception than children with bilateral CIs ( p < .0001) but balance and language deficits ( p = .0004, p < .0001, respectively) were similar in the two hearing loss groups ( p > .05). Visuospatial memory deficits occurred in both hearing loss groups ( p = .02) but more consistently across tests in children with unilateral hearing loss. Verbal memory was not significantly different than normal ( p > .05). Principal component analyses revealed deficits in a main cluster of visuospatial memory, oral language, mathematics, and reading measures (explaining 46.8% data variability). The remaining components revealed clusters of self-reported hearing, balance and vestibular function, and speech perception deficits. The findings indicate significant developmental impacts of poor binaural hearing in children.

scholarly journals Initial Development of a Spatially Separated Speech-in-Noise and Localization Training Program

2010 ◽  
Vol 21 (06) ◽  
pp. 390-403 ◽  
Author(s):  
Richard S. Tyler ◽  
Shelley A. Witt ◽  
Camille C. Dunn ◽  
Wenjun Wang
Keyword(s):  
Cochlear Implants ◽  
Hearing Aids ◽  
Spatial Separation ◽  
Binaural Hearing ◽  
Training System ◽  
Initial Development ◽  
Bilateral Cochlear Implants ◽  
Speech In Noise ◽  
Novel Approach ◽  
Home Based

Objective: This article describes the initial development of a novel approach for training hearing-impaired listeners to improve their ability to understand speech in the presence of background noise and to also improve their ability to localize sounds. Design: Most people with hearing loss, even those well fit with hearing devices, still experience significant problems understanding speech in noise. Prior research suggests that at least some subjects can experience improved speech understanding with training. However, all training systems that we are aware of have one basic, critical limitation. They do not provide spatial separation of the speech and noise, therefore ignoring the potential benefits of training binaural hearing. In this paper we describe our initial experience with a home-based training system that includes spatially separated speech-in-noise and localization training. Results: Throughout the development of this system patient input, training and preliminary pilot data from individuals with bilateral cochlear implants were utilized. Positive feedback from subjective reports indicated that some individuals were engaged in the treatment, and formal testing showed benefit. Feedback and practical issues resulted from the reduction of an eight-loudspeaker to a two-loudspeaker system. Conclusions: These preliminary findings suggest we have successfully developed a viable spatial hearing training system that can improve binaural hearing in noise and localization. Applications include, but are not limited to, hearing with hearing aids and cochlear implants.

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