Sound Localization in Single-Sided Deaf Participants Provided With a Cochlear Implant

Spatial hearing is crucial in real life but deteriorates in participants with severe sensorineural hearing loss or single-sided deafness. This ability can potentially be improved with a unilateral cochlear implant (CI). The present study investigated measures of sound localization in participants with single-sided deafness provided with a CI. Sound localization was measured separately at eight loudspeaker positions (4°, 30°, 60°, and 90°) on the CI side and on the normal-hearing side. Low- and high-frequency noise bursts were used in the tests to investigate possible differences in the processing of interaural time and level differences. Data were compared to normal-hearing adults aged between 20 and 83. In addition, the benefit of the CI in speech understanding in noise was compared to the localization ability. Fifteen out of 18 participants were able to localize signals on the CI side and on the normal-hearing side, although performance was highly variable across participants. Three participants always pointed to the normal-hearing side, irrespective of the location of the signal. The comparison with control data showed that participants had particular difficulties localizing sounds at frontal locations and on the CI side. In contrast to most previous results, participants were able to localize low-frequency signals, although they localized high-frequency signals more accurately. Speech understanding in noise was better with the CI compared to testing without CI, but only at a position where the CI also improved sound localization. Our data suggest that a CI can, to a large extent, restore localization in participants with single-sided deafness. Difficulties may remain at frontal locations and on the CI side. However, speech understanding in noise improves when wearing the CI. The treatment with a CI in these participants might provide real-world benefits, such as improved orientation in traffic and speech understanding in difficult listening situations

International Classification of Reliability for Implanted Cochlear Implant Receiver Stimulators

To design an international standard to be used when reporting reliability of the implanted components of cochlear implant systems to appropriate governmental authorities, cochlear implant (CI) centers, and for journal editors in evaluating manuscripts involving cochlear implant reliability

Sound Localization in Single-Sided Deaf Participants Provided With a Cochlear Implant

Spatial hearing is crucial in real life but deteriorates in participants with severe sensorineural hearing loss or single-sided deafness. This ability can potentially be improved with a unilateral cochlear implant (CI). The present study investigated measures of sound localization in participants with single-sided deafness provided with a CI. Sound localization was measured separately at eight loudspeaker positions (4°, 30°, 60°, and 90°) on the CI side and on the normal-hearing side. Low- and high-frequency noise bursts were used in the tests to investigate possible differences in the processing of interaural time and level differences. Data were compared to normal-hearing adults aged between 20 and 83. In addition, the benefit of the CI in speech understanding in noise was compared to the localization ability. Fifteen out of 18 participants were able to localize signals on the CI side and on the normal-hearing side, although performance was highly variable across participants. Three participants always pointed to the normal-hearing side, irrespective of the location of the signal. The comparison with control data showed that participants had particular difficulties localizing sounds at frontal locations and on the CI side. In contrast to most previous results, participants were able to localize low-frequency signals, although they localized high-frequency signals more accurately. Speech understanding in noise was better with the CI compared to testing without CI, but only at a position where the CI also improved sound localization. Our data suggest that a CI can, to a large extent, restore localization in participants with single-sided deafness. Difficulties may remain at frontal locations and on the CI side. However, speech understanding in noise improves when wearing the CI. The treatment with a CI in these participants might provide real-world benefits, such as improved orientation in traffic and speech understanding in difficult listening situations

Sound Localization in Single-Sided Deaf Participants Provided With a Cochlear Implant

Spatial hearing is crucial in real life but deteriorates in participants with severe sensorineural hearing loss or single-sided deafness. This ability can potentially be improved with a unilateral cochlear implant (CI). The present study investigated measures of sound localization in participants with single-sided deafness provided with a CI. Sound localization was measured separately at eight loudspeaker positions (4°, 30°, 60°, and 90°) on the CI side and on the normal-hearing side. Low- and high-frequency noise bursts were used in the tests to investigate possible differences in the processing of interaural time and level differences. Data were compared to normal-hearing adults aged between 20 and 83. In addition, the benefit of the CI in speech understanding in noise was compared to the localization ability. Fifteen out of 18 participants were able to localize signals on the CI side and on the normal-hearing side, although performance was highly variable across participants. Three participants always pointed to the normal-hearing side, irrespective of the location of the signal. The comparison with control data showed that participants had particular difficulties localizing sounds at frontal locations and on the CI side. In contrast to most previous results, participants were able to localize low-frequency signals, although they localized high-frequency signals more accurately. Speech understanding in noise was better with the CI compared to testing without CI, but only at a position where the CI also improved sound localization. Our data suggest that a CI can, to a large extent, restore localization in participants with single-sided deafness. Difficulties may remain at frontal locations and on the CI side. However, speech understanding in noise improves when wearing the CI. The treatment with a CI in these participants might provide real-world benefits, such as improved orientation in traffic and speech understanding in difficult listening situations

Binaural interaction in electrically and acoustically evoked auditory brainstem responses in six bimodal listeners

Introduction: ‘Bimodal hearing’ refers to the condition in which electrical hearing via a cochlear implant (CI) is combined with residual hearing in the non-implanted ear. Several studies show bimodal advantages in terms of speech perception in noise, sound localization and overall sound quality. There is ongoing debate whether bimodal listeners only benefit from the presence of temporal fine-structure or if they also benefit from binaural cues. The objective of this study is to gain insight into binaural processing in bimodal patients. Methods: Six bimodal listeners participated in the study. Binaural hearing is investigated using behavioural tests and auditory brainstem responses (ABRs). ABRs are recorded in three stimulus conditions: monaural left, monaural right and binaural stimulation. A binaural interaction component is derived from the ABR (ABR-BIC) by subtracting the binaural response from the sum of the monaural responses. In a first measurement, this subtraction paradigm was applied without accounting for the latency differences between the ABR wave V and the eABR wave eV. In a second measurement, the electric stimulation was delayed by the latency difference between waves V and eV. The presence of the ABR-BIC is linked to performance on speech in noise, sound localization and scores on the Speech Spatial Qualities of Hearing Scale (SSQ). Results: Electric-acoustic ABR-BIC and behavioural performance in six bimodal listeners will be presented. Conclusion: We expect to find a relationship between behavioral performance and the electrophysiological data

The binaural interaction component: a method to monitor plasticity in bimodal listeners?

Objectives: To investigate plasticity in the binaural auditory system in bimodal listeners. Background: Bimodal hearing refers to the condition in which electric hearing via a cochlear implant (CI) is combined with residual hearing in the non-implanted ear. Psychoacoustic research suggests that bimodal listeners can benefit from binaural integration. There is, however, an unexplained variability in bimodal outcome. It is hypothesized that at least some of this variability can be explained by plasticity. It is expected that binaural interaction develops with increasing bimodal experience. Furthermore, subjects who wore bilateral hearing aids may be more likely to binaurally integrate electric and acoustic signals. We believe that the binaural interaction component derived from the auditory brainstem response (ABR-BIC) can be a useful technique to measure plastic changes during the first months of bimodal hearing. Methods: ABR-BICs are computed by subtracting the binaural response from the sum of the left and right monaural responses. A protocol that combines acoustic and electric stimulation is set up to obtain ABR-BICs in bimodal listeners. In a first study, ABR-BICs are measured by accounting for the latency differences between the acoustic and the electric wave V. In a second study, ABR-BICs are measured without accounting for this. Results: Both protocols will be presented, as well as the results of a pilot study. Preliminary data of the first study suggests that binaural interaction can occur in bimodal listeners. Conclusions: A better understanding of the mechanisms of inter-subject variability in binaural interaction can lead to better and more adequate counseling

Binaural interaction in the auditory brainstem response : a normative study

Objective: Binaural interaction can be investigated using auditory evoked potentials. A binaural interaction component can be derived from the auditory brainstem response (ABR-BIC) and is considered evidence for binaural interaction at the level of the brainstem. Although click ABR-BIC has been investigated thoroughly, data on 500. Hz tone-burst (TB) ABR-BICs are scarce. In this study, characteristics of click and 500. Hz TB ABR-BICs are described. Furthermore, reliability of both click and 500. Hz TB ABR-BIC are investigated. Methods: Eighteen normal hearing young adults (eight women, ten men) were included. ABRs were recorded in response to clicks and 500. Hz TBs. ABR-BICs were derived by subtracting the binaural response from the sum of the monaural responses measured in opposite ears. Results: Good inter-rater reliability is obtained for both click and 500. Hz TB ABR-BICs. The most reliable peak in click ABR-BIC occurs at a mean latency of 6.06. ms (SD 0.354. ms). Reliable 500. Hz TB ABR-BIC are obtained with a mean latency of 9.47. ms (SD 0.678. ms). Amplitudes are larger for 500. Hz TB ABR-BIC than for clicks. Conclusion: The most reliable peak in click ABR-BIC occurs at the downslope of wave V. Five hundred Hertz TB ABR-BIC is characterized by a broad positivity occurring at the level of wave V. Significance: The ABR-BIC is a useful technique to investigate binaural interaction in certain populations. Examples are bilateral hearing aid users, bilateral cochlear implant users and bimodal listeners. The latter refers to the combination of unilateral cochlear implantation and contralateral residual hearing. The majority of these patients have residual hearing in the low frequencies. The current study suggests that 500. Hz TB ABR-BIC may be a suitable technique to assess binaural interaction in this specific population of cochlear implant users.8 page(s