scholarly journals Spectrotemporal Modulation Sensitivity in Cochlear-Implant and Normal-Hearing Listeners: Is the Performance Driven by Temporal or Spectral Modulation Sensitivity?

2020 ◽  
Vol 24 ◽  
pp. 233121652094838
Author(s):  
Ning Zhou ◽  
Susannah Dixon ◽  
Zhen Zhu ◽  
Lixue Dong ◽  
Marti Weiner
Keyword(s):  
Information Processing ◽  
Speech Recognition ◽  
Cochlear Implant ◽  
Modulation Depth ◽  
General Pattern ◽  
Normal Hearing ◽  
Temporal Information ◽  
Spectral Modulation ◽  
Highly Correlated ◽  
Stimulus Modulation

This study examined the contribution of temporal and spectral modulation sensitivity to discrimination of stimuli modulated in both the time and frequency domains. The spectrotemporally modulated stimuli contained spectral ripples that shifted systematically across frequency over time at a repetition rate of 5 Hz. As the ripple density increased in the stimulus, modulation depth of the 5 Hz amplitude modulation (AM) reduced. Spectrotemporal modulation discrimination was compared with subjects’ ability to discriminate static spectral ripples and the ability to detect slow AM. The general pattern from both the cochlear implant (CI) and normal hearing groups showed that spectrotemporal modulation thresholds were correlated more strongly with AM detection than with static ripple discrimination. CI subjects’ spectrotemporal modulation thresholds were also highly correlated with speech recognition in noise, when partialing out static ripple discrimination, but the correlation was not significant when partialing out AM detection. The results indicated that temporal information was more heavily weighted in spectrotemporal modulation discrimination, and for CI subjects, it was AM sensitivity that drove the correlation between spectrotemporal modulation thresholds and speech recognition. The results suggest that for the rates tested here, temporal information processing may limit performance more than spectral information processing in both CI users and normal hearing listeners.

scholarly journals Multisensory integration-attention trade-off in cochlear-implanted deaf individuals

2020 ◽  
Author(s):  
Luuk P.H. van de Rijt ◽  
A. John van Opstal ◽  
Marc M. van Wanrooij
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Divided Attention ◽  
Normal Hearing ◽  
Visual Speech ◽  
Speech Comprehension ◽  
Noisy Environments ◽  
Trade Off ◽  
Attentional Resources ◽  
Attention Tasks

AbstractThe cochlear implant (CI) allows profoundly deaf individuals to partially recover hearing. Still, due to the coarse acoustic information provided by the implant, CI users have considerable difficulties in recognizing speech, especially in noisy environments, even years after implantation. CI users therefore rely heavily on visual cues to augment speech comprehension, more so than normal-hearing individuals. However, it is unknown how attention to one (focused) or both (divided) modalities plays a role in multisensory speech recognition. Here we show that unisensory speech listening and speech reading were negatively impacted in divided-attention tasks for CI users - but not for normal-hearing individuals. Our psychophysical experiments revealed that, as expected, listening thresholds were consistently better for the normal-hearing, while lipreading thresholds were largely similar for the two groups. Moreover, audiovisual speech recognition for normal-hearing individuals could be described well by probabilistic summation of auditory and visual speech recognition, while CI users were better integrators than expected from statistical facilitation alone. Our results suggest that this benefit in integration, however, comes at a cost. Unisensory speech recognition is degraded for CI users when attention needs to be divided across modalities, i.e. in situations with uncertainty about the upcoming stimulus modality. We conjecture that CI users exhibit an integration-attention trade-off. They focus solely on a single modality during focused-attention tasks, but need to divide their limited attentional resources to more modalities during divided-attention tasks. We argue that in order to determine the benefit of a CI for speech comprehension, situational factors need to be discounted by presenting speech in realistic or complex audiovisual environments.Significance statementDeaf individuals using a cochlear implant require significant amounts of effort to listen in noisy environments due to their impoverished hearing. Lipreading can benefit them and reduce the burden of listening by providing an additional source of information. Here we show that the improved speech recognition for audiovisual stimulation comes at a cost, however, as the cochlear-implant users now need to listen and speech-read simultaneously, paying attention to both modalities. The data suggests that cochlear-implant users run into the limits of their attentional resources, and we argue that they, unlike normal-hearing individuals, always need to consider whether a multisensory benefit outweighs the unisensory cost in everyday environments.

Speech recognition by normal-hearing and cochlear implant listeners as a function of intensity resolution

2000 ◽  
Vol 108 (5) ◽  
pp. 2377-2387 ◽  
Author(s):  
Philipos C. Loizou ◽  
Michael Dorman ◽  
Oguz Poroy ◽  
Tony Spahr
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Normal Hearing ◽  
Intensity Resolution

Improving Speech Perception in Noise for Children with Cochlear Implants

2011 ◽  
Vol 22 (09) ◽  
pp. 623-632 ◽  
Author(s):  
René H. Gifford ◽  
Amy P. Olund ◽  
Melissa DeJong
Keyword(s):  
Speech Recognition ◽  
Speech Perception ◽  
Cochlear Implant ◽  
Cochlear Implants ◽  
Repeated Measures ◽  
Background Noise ◽  
Normal Hearing ◽  
Speech Understanding ◽  
The Mean ◽  
Experimental Subjects

Background: Current cochlear implant recipients are achieving increasingly higher levels of speech recognition; however, the presence of background noise continues to significantly degrade speech understanding for even the best performers. Newer generation Nucleus cochlear implant sound processors can be programmed with SmartSound strategies that have been shown to improve speech understanding in noise for adult cochlear implant recipients. The applicability of these strategies for use in children, however, is not fully understood nor widely accepted. Purpose: To assess speech perception for pediatric cochlear implant recipients in the presence of a realistic restaurant simulation generated by an eight-loudspeaker (R-SPACE™) array in order to determine whether Nucleus sound processor SmartSound strategies yield improved sentence recognition in noise for children who learn language through the implant. Research Design: Single subject, repeated measures design. Study Sample: Twenty-two experimental subjects with cochlear implants (mean age 11.1 yr) and 25 control subjects with normal hearing (mean age 9.6 yr) participated in this prospective study. Intervention: Speech reception thresholds (SRT) in semidiffuse restaurant noise originating from an eight-loudspeaker array were assessed with the experimental subjects’ everyday program incorporating Adaptive Dynamic Range Optimization (ADRO) as well as with the addition of Autosensitivity control (ASC). Data Collection and Analysis: Adaptive SRTs with the Hearing In Noise Test (HINT) sentences were obtained for all 22 experimental subjects, and performance—in percent correct—was assessed in a fixed +6 dB SNR (signal-to-noise ratio) for a six-subject subset. Statistical analysis using a repeated-measures analysis of variance (ANOVA) evaluated the effects of the SmartSound setting on the SRT in noise. Results: The primary findings mirrored those reported previously with adult cochlear implant recipients in that the addition of ASC to ADRO significantly improved speech recognition in noise for pediatric cochlear implant recipients. The mean degree of improvement in the SRT with the addition of ASC to ADRO was 3.5 dB for a mean SRT of 10.9 dB SNR. Thus, despite the fact that these children have acquired auditory/oral speech and language through the use of their cochlear implant(s) equipped with ADRO, the addition of ASC significantly improved their ability to recognize speech in high levels of diffuse background noise. The mean SRT for the control subjects with normal hearing was 0.0 dB SNR. Given that the mean SRT for the experimental group was 10.9 dB SNR, despite the improvements in performance observed with the addition of ASC, cochlear implants still do not completely overcome the speech perception deficit encountered in noisy environments accompanying the diagnosis of severe-to-profound hearing loss. Conclusion: SmartSound strategies currently available in latest generation Nucleus cochlear implant sound processors are able to significantly improve speech understanding in a realistic, semidiffuse noise for pediatric cochlear implant recipients. Despite the reluctance of pediatric audiologists to utilize SmartSound settings for regular use, the results of the current study support the addition of ASC to ADRO for everyday listening environments to improve speech perception in a child's typical everyday program.

scholarly journals The Relationship Between Spectral Modulation Detection and Speech Recognition: Adult Versus Pediatric Cochlear Implant Recipients

2018 ◽  
Vol 22 ◽  
pp. 233121651877117 ◽  
Author(s):  
René H. Gifford ◽  
Jack H. Noble ◽  
Stephen M. Camarata ◽  
Linsey W. Sunderhaus ◽  
Robert T. Dwyer ◽  
...  
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Spectral Modulation ◽  
Modulation Detection ◽  
The Relationship

Simulating bipolar and monopolar cochlear‐implant stimulation in speech recognition by normal‐hearing listeners

2007 ◽  
Vol 121 (5) ◽  
pp. 3185-3185
Author(s):  
Mohamed Bingabr ◽  
Blas Espinoza‐Varas ◽  
Philip C. Loizou ◽  
Kenneth Hawkins
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Normal Hearing

The Relative Importance of Amplitude, Temporal, and Spectral Cues for Cochlear Implant Processor Design

2002 ◽  
Vol 11 (2) ◽  
pp. 124-127 ◽  
Author(s):  
Robert V. Shannon
Keyword(s):  
Speech Recognition ◽  
Cochlear Implant ◽  
Speech Intelligibility ◽  
Normal Hearing ◽  
Spectral Information ◽  
Speech Understanding ◽  
Prosthetic Devices ◽  
Spectral Cues ◽  
Temporal Cues ◽  
Types Of Information

Speech understanding with cochlear implants has improved steadily over the last 25 years, and the success of implants has provided a powerful tool for understanding speech recognition in general. Comparing speech recognition in normal-hearing listeners and in cochlear-implant listeners has revealed many important lessons about the types of information necessary for good speech recognition—and some of the lessons are surprising. This paper presents a summary of speech perception research over the last 25 years with cochlear-implant and normal-hearing listeners. As long as the speech is audible, even the relatively severe amplitude distortion has only a mild effect on intelligibility. Temporal cues appear to be useful for speech intelligibility only up to about 20 Hz. Whereas temporal information above 20 Hz may contribute to improved quality, it contributes little to speech understanding. In contrast, the quantity and quality of spectral information appear to be critical for speech understanding. Only four spectral "channels" of information can produce good speech understanding, but more channels are required for difficult listening situations. Speech understanding is sensitive to the placement of spectral information along the cochlea. In prosthetic devices, in which the spectral information can be delivered to any cochlear location, it is critical to present spectral information to the normal acoustic tonotopic location for that information. If there is a shift or distortion of 2 to 3 mm between frequency and cochlear place, speech recognition is decreased dramatically.

scholarly journals Across-Frequency Temporal Processing and Speech Perception in Cochlear Implant Recipients and Normal Hearing Listeners

2020 ◽  
Author(s):  
Chelsea Blankenship ◽  
Jareen Meinzen-Derr ◽  
Fawen Zhang
Keyword(s):  
Speech Recognition ◽  
Speech Perception ◽  
Correlation Analysis ◽  
Cochlear Implant ◽  
Canonical Correlation Analysis ◽  
Temporal Processing ◽  
Canonical Correlation ◽  
Normal Hearing ◽  
Gap Detection ◽  
Bivariate Correlation

Objective: Individual differences in temporal processing contributes strongly to the large variability in speech recognition performance observed among cochlear implant (CI) recipients. Temporal processing is traditionally measured using a behavioral gap detection task, and therefore, it can be challenging or infeasible to obtain reliable responses from young children and individuals with disabilities. Within-frequency gap detection (pre- and post-gap markers are identical in frequency) is more common, yet across-frequency gap detection (pre- and post-gap markers are spectrally distinct), is thought to be more important for speech perception because the phonemes that proceed and follow the rapid temporal cues are rarely identical in frequency. However, limited studies have examined across-frequency temporal processing in CI recipients. None of which have included across-frequency cortical auditory evoked potentials (CAEP), nor was the correlation between across-frequency gap detection and speech perception examined. The purpose of the study is to evaluate behavioral and electrophysiological measures of across-frequency temporal processing and speech recognition in normal hearing (NH) and CI recipients. Design: Eleven post-lingually deafened adult CI recipients (n = 15 ears, mean age = 50.4 yrs.) and eleven age- and gender-matched NH individuals participated (n = 15 ears; mean age = 49.0 yrs.). Speech perception was evaluated using the Minimum Speech Test Battery for Adult Cochlear Implant Users (CNC, AzBio, BKB-SIN). Across-frequency behavioral gap detection thresholds (GDT; 2 kHz to 1 kHz post-gap tone) were measured using an adaptive, two-alternative, forced-choice paradigm. Across-frequency CAEPs were measured using four gap duration conditions; supra-threshold (behavioral GDT x 3), threshold (behavioral GDT), sub-threshold (behavioral GDT/3), and reference (no gap) condition. Group differences in behavioral GDTs, and CAEP amplitude and latency were evaluated using multiple mixed effects models. Bivariate and multivariate canonical correlation analyses were used to evaluate the relationship between the CAEP amplitude and latency, behavioral GDTs, and speech perception. Results: A significant effect of participant group was not observed for across-frequency GDTs, instead older participants (> 50 yrs.) displayed larger GDTs than younger participants. CI recipients displayed increased P1 and N1 latency compared to NH participants and older participants displayed delayed N1 and P2 latency compared to younger adults. Bivariate correlation analysis between behavioral GDTs and speech perception measures were not significant (p > 0.01). Across-frequency canonical correlation analysis showed a significant relationship between CAEP reference condition and behavioral measures of speech perception and temporal processing. Conclusions: CI recipients show similar across-frequency temporal GDTs compared to NH participants, however older participants (> 50 yrs.) displayed poorer temporal processing (larger GDTs) compared to younger participants. CI recipients and older participants displayed less efficient neural processing of the acoustic stimulus and slower transmission to the auditory cortex. An effect of gap duration on CAEP amplitude or latency was not observed. Canonical correlation analysis suggests better cortical detection of frequency changes is correlated with better word and sentence understanding in quiet and noise.

scholarly journals Speeded detection of spectrotemporal modulations of sound

2022 ◽  
Author(s):  
Lidwien C.E. Veugen ◽  
A. John Van Opstal ◽  
Marc M. van Wanrooij
Keyword(s):  
Reaction Time ◽  
Cochlear Implant ◽  
Modulation Depth ◽  
Hearing Aid ◽  
Reaction Time Task ◽  
Normal Hearing ◽  
Impaired Hearing ◽  
Sensitivity Matrix ◽  
Detection Rates ◽  
Time Task

We tested whether joint spectrotemporal sensitivity follows from spectrotemporal separability for normal-hearing conditions and for impaired-hearing simulations. In a manual reaction-time task, normal-hearing listeners had to detect the onset of a ripple (with density between 0-8 cycles/octave and a fixed modulation depth of 50%), that moved up or down the log-frequency axis at constant velocity (between 0-64 Hz), in an otherwise-unmodulated broadband white-noise. Spectral and temporal modulations elicited band-pass filtered sensitivity characteristics, with fastest detection rates around 1 cycle/oct and 32 Hz for normal-hearing conditions. These results closely resemble data from other studies that typically used the modulation-depth threshold as a sensitivity measure for spectral-temporal modulations. To simulate hearing-impairment, stimuli were processed with a 6-channel cochlear-implant vocoder, and a hearing-aid simulation that introduced spectral smearing and low-pass filtering. Reaction times were always much slower compared to normal hearing, especially for the highest spectral densities. Binaural performance was predicted well by the benchmark race model of statistical facilitation of independent monaural channels. For the impaired-hearing simulations this implied a "best-of-both-worlds" principle in which the listeners relied on the hearing-aid ear to detect spectral modulations, and on the cochlear-implant ear for temporal-modulation detection. Although singular-value decomposition indicated that the joint spectrotemporal sensitivity matrix could be largely reconstructed from independent temporal and spectral sensitivity functions, in line with time-spectrum separability, a significant inseparable spectral-temporal interaction was present in all hearing conditions. These results imply that the reaction-time task yields a solid and effective objective measure of acoustic spectrotemporal modulation sensitivity, which may also be applicable to hearing-impaired individuals.

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