Spatial release from masking in simulations of cochlear implants for single-sided deafness

Purpose The aim of the study was to assess the susceptibility to energetic and informational masking in patients with single-sided deafness (SSD) with one normal-hearing (NH) ear and a cochlear implant (CI) in the contralateral ear, understand the effect on speech recognition when spatially separating noise and speech maskers, and investigate the influence of the CI in situations with energetic and informational masking. Method Speech recognition was measured in the presence of either a modulated speech-shaped noise or one of two competing speech maskers in 11 SSD-CI listeners. The speech maskers were manipulated with respect to fundamental frequency to consider the effect of different voices. Measurements were conducted in the unaided (NH) and aided (NHCI) conditions. Spatial release from masking (SRM) was calculated for each masker type and both listening conditions (NH and NHCI) by subtracting scores of the colocated target and masker condition (S 0 N 0 ) from the spatially separated target and masker conditions (S 0 N ≠0 ). Results Speech recognition was highly variable depending on the type of masker. SRM occurred in the unaided (NH) and aided (NHCI) conditions when the speech masker had the same gender as the target talker. Adding the CI improved speech recognition when this speech masker was ipsilateral to the NH ear. Conclusions The amount of informational masking is substantial in SSD-CI listeners with both colocated and spatially separated target and masker signals. The contribution of SRM to better speech recognition largely depends on the masker and is considerable when no differences in voices between the target and the competing talker occur. There is only a slight improvement in speech recognition by adding the CI.

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The impact of cochlear implant microphone settings on the binaural hearing of experienced cochlear implant users with single-sided deafness

European Archives of Oto-Rhino-Laryngology ◽

10.1007/s00405-020-06450-5 ◽

2020 ◽

Author(s):

Anja Kurz ◽

Maren Zanzinger ◽

Rudolf Hagen ◽

Kristen Rak

Keyword(s):

Speech Perception ◽

Cochlear Implant ◽

Binaural Hearing ◽

Sound Quality ◽

Noise Sources ◽

Shadow Effect ◽

Spatial Release ◽

Release From Masking ◽

Single Sided Deafness ◽

The Impact

Abstract Objective Cochlear implantation has become a well-accepted treatment option for people with single-sided deafness (SSD) and has become a clinical standard in many countries. A cochlear implant (CI) is the only device which restores binaural hearing. The effect of microphone directionality (MD) settings has been investigated in other CI indication groups, but its impact on speech perception in noise has not been established in CI users with SSD. The focus of this investigation was, therefore, to assess binaural hearing effects using different MD settings in CI users with SSD. Methods Twenty-nine experienced CI users with SSD were recruited to determine speech reception thresholds with varying target and noise sources to define binaural effects (head shadow, squelch, summation, and spatial release from masking), sound localization, and sound quality using the SSQ12 and HISQUI19 questionnaires. Outcome measures included the MD settings “natural”, “adaptive”, and “omnidirectional”. Results The 29 participants involved in the study were divided into two groups: 11 SONNET users and 18 OPUS 2/RONDO users. In both groups, a significant head shadow effect of 7.4–9.2 dB was achieved with the CI. The MD setting “adaptive” provided a significant head shadow effect of 9.2 dB, a squelch effect of 0.9 dB, and spatial release from masking of 7.6 dB in the SONNET group. No significant summation effect could be determined in either group with CI. Outcomes with the omnidirectional setting were not significantly different between groups. For both groups, localization improved significantly when the CI was activated and was best when the omnidirectional setting was used. The groups’ sound quality scores did not significantly differ. Conclusions Adaptive directional microphone settings improve speech perception and binaural hearing abilities in CI users with SSD. Binaural effect measures are valuable to quantify the benefit of CI use, especially in this indication group.

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

Journal of Speech Language and Hearing Research ◽

10.1044/2017_jslhr-h-16-0441 ◽

2018 ◽

Vol 61 (3) ◽

pp. 752-761 ◽

Cited By ~ 1

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.

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Spatial Release From Masking in Pediatric Cochlear Implant Recipients With Single-Sided Deafness

American Journal of Audiology ◽

10.1044/2020_aja-20-00119 ◽

2021 ◽

pp. 1-9

Author(s):

Lisa R. Park ◽

Margaret T. Dillon ◽

Emily Buss ◽

Brendan P. O'Connell ◽

Kevin D. Brown

Keyword(s):

Speech Recognition ◽

Cochlear Implant ◽

Cochlear Implantation ◽

Repeated Measures ◽

Case Reports ◽

Recognition Task ◽

Normal Hearing ◽

Spatial Release ◽

Release From Masking ◽

Single Sided Deafness

Purpose Children with single-sided deafness (SSD) experience difficulty understanding speech in multisource listening situations. Case reports and retrospective studies have indicated that a cochlear implant (CI) may improve masked speech recognition in children with SSD. This prospective study was conducted to determine whether providing a CI to children with SSD supports spatial release from masking (SRM), an improvement in speech recognition associated with separating the target and masker sources. Method Twenty children with at least a moderate-to-profound hearing loss in one ear and normal hearing in the contralateral ear underwent cochlear implantation. The average age of implantation was 5.5 years (range: 3.5–12.7). After 12 months of CI use, subjects completed a sentence recognition task in multitalker masker with and without the CI. The target was presented from the front, and the masker was either colocated with the target (0°) or from the side (+90° or −90°). A two-way repeated-measures analysis of variance was completed to investigate SRM with and without the CI. Results Pediatric CI recipients experienced significant SRM when the masker was directed to the normal-hearing ear or to the affected ear. Conclusions The results indicate that cochlear implantation in children with SSD supports binaural skills required for speech recognition in noise. These results are consistent with improved functional communication in multisource environments, like classrooms.

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