A functionally relevant measure of spatial release from masking in children with bilateral cochlear implants

2018 ◽  
Vol 144 (3) ◽  
pp. 1793-1793
Author(s):  
Z. Ellen Peng ◽  
Ruth Litovsky
Keyword(s):  
Cochlear Implants ◽  
Bilateral Cochlear Implants ◽  
Spatial Release ◽  
Release From Masking

scholarly journals Spatial Release From Masking in Adults With Bilateral Cochlear Implants: Effects of Distracter Azimuth and Microphone Location

2018 ◽  
Vol 61 (3) ◽  
pp. 752-761 ◽  
Author(s):  
Timothy J. Davis ◽  
René H. Gifford
Keyword(s):  
Cochlear Implants ◽  
Spatial Configuration ◽  
Block Design ◽  
Speech Understanding ◽  
Traditional Assessment ◽  
Bilateral Cochlear Implants ◽  
Secondary Purpose ◽  
Spatial Release ◽  
Bilateral Cochlear Implant ◽  
Release From Masking

PurposeThe primary purpose of this study was to derive spatial release from masking (SRM) performance-azimuth functions for bilateral cochlear implant (CI) users to provide a thorough description of SRM as a function of target/distracter spatial configuration. The secondary purpose of this study was to investigate the effect of the microphone location for SRM in a within-subject study design.MethodSpeech recognition was measured in 12 adults with bilateral CIs for 11 spatial separations ranging from −90° to +90° in 20° steps using an adaptive block design. Five of the 12 participants were tested with both the behind-the-ear microphones and a T-mic configuration to further investigate the effect of mic location on SRM.ResultsSRM can be significantly affected by the hemifield origin of the distracter stimulus—particularly for listeners with interaural asymmetry in speech understanding. The greatest SRM was observed with a distracter positioned 50° away from the target. There was no effect of mic location on SRM for the current experimental design.ConclusionOur results demonstrate that the traditional assessment of SRM with a distracter positioned at 90° azimuth may underestimate maximum performance for individuals with bilateral CIs.

Binaural Speech Understanding With Bilateral Cochlear Implants in Reverberation

2018 ◽  
Vol 27 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Kostas Kokkinakis
Keyword(s):  
Sound Field ◽  
Spatial Location ◽  
Speech Understanding ◽  
Spatial Cues ◽  
Bilateral Cochlear Implants ◽  
Positive Effects ◽  
Spatial Release ◽  
Listening Environments ◽  
Speech Reception Thresholds ◽  
Release From Masking

PurposeThe purpose of this study was to investigate whether bilateral cochlear implant (CI) listeners who are fitted with clinical processors are able to benefit from binaural advantages under reverberant conditions. Another aim of this contribution was to determine whether the magnitude of each binaural advantage observed inside a highly reverberant environment differs significantly from the magnitude measured in a near-anechoic environment.MethodTen adults with postlingual deafness who are bilateral CI users fitted with either Nucleus 5 or Nucleus 6 clinical sound processors (Cochlear Corporation) participated in this study. Speech reception thresholds were measured in sound field and 2 different reverberation conditions (0.06 and 0.6 s) as a function of the listening condition (left, right, both) and the noise spatial location (left, front, right).ResultsThe presence of the binaural effects of head-shadow, squelch, summation, and spatial release from masking in the 2 different reverberation conditions tested was determined using nonparametric statistical analysis. In the bilateral population tested, when the ambient reverberation time was equal to 0.6 s, results indicated strong positive effects of head-shadow and a weaker spatial release from masking advantage, whereas binaural squelch and summation contributed no statistically significant benefit to bilateral performance under this acoustic condition. These findings are consistent with those of previous studies, which have demonstrated that head-shadow yields the most pronounced advantage in noise. The finding that spatial release from masking produced little to almost no benefit in bilateral listeners is consistent with the hypothesis that additive reverberation degrades spatial cues and negatively affects binaural performance.ConclusionsThe magnitude of 4 different binaural advantages was measured on the same group of bilateral CI subjects fitted with clinical processors in 2 different reverberation conditions. The results of this work demonstrate the impeding properties of reverberation on binaural speech understanding. In addition, results indicate that CI recipients who struggle in everyday listening environments are also more likely to benefit less in highly reverberant environments from their bilateral processors.

Bimodal Fitting and Bilateral Cochlear Implants in Children With Significant Residual Hearing: The Impact of Asymmetry in Spatial Release of Masking on Localization

2021 ◽  
pp. 1-14
Author(s):  
Marloes Sparreboom ◽  
Sebastián Ausili ◽  
Martijn J. H. Agterberg ◽  
Emmanuel A. M. Mylanus
Keyword(s):  
Decision Making ◽  
Cochlear Implants ◽  
Fundamental Frequency ◽  
Hearing Aid ◽  
Normal Hearing ◽  
Residual Hearing ◽  
Bilateral Cochlear Implants ◽  
Spatial Release ◽  
Left Right Asymmetry ◽  
The Impact

Purpose This study aimed to gain more insight into the primary auditory abilities of children with significant residual hearing in order to improve decision making when choosing between bimodal fitting or sequential bilateral cochlear implantation. Method Sound localization abilities, spatial release of masking, and fundamental frequency perception were tested. Nine children with bimodal fitting and seven children with sequential bilateral cochlear implants were included in the study. As a reference, 15 children with normal hearing and two children with simultaneous bilateral cochlear implants were included. Results On all outcome measures, the implanted children performed worse than the normal hearing children. For high-frequency localization, children with sequential bilateral cochlear implants performed significantly better than children with bimodal fitting. Compared to children with normal hearing, the left–right asymmetry in spatial release of masking was significant. When the implant was hindered by noise, bimodally fitted children obtained significantly lower spatial release of masking compared to when the hearing aid was hindered by noise. Overall, the larger the left–right asymmetry in spatial release of masking, the poorer the localization skills. No significant differences were found in fundamental frequency perception between the implant groups. Conclusions The data hint to an advantage of bilateral implantation over bimodal fitting. The extent of asymmetry in spatial release of masking is a promising tool for decision making when choosing whether to continue with the hearing aid or to provide a second cochlear implant in children with significant residual hearing.

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