Ideal Time–Frequency Masking Algorithms Lead to Different Speech Intelligibility and Quality in Normal-Hearing and Cochlear Implant Listeners

This paper describes a logatome discrimination test for the assessment of speech perception in cochlear implant users (CI users), based on a multilingual speech database, the Oldenburg Logatome Corpus, which was originally recorded for the comparison of human and automated speech recognition. The logatome discrimination task is based on the presentation of 100 logatome pairs (i.e., nonsense syllables) with balanced representations of alternating “vowel-replacement” and “consonant-replacement” paradigms in order to assess phoneme confusions. Thirteen adult normal hearing listeners and eight adult CI users, including both good and poor performers, were included in the study and completed the test after their speech intelligibility abilities were evaluated with an established sentence test in noise. Furthermore, the discrimination abilities were measured electrophysiologically by recording the mismatch negativity (MMN) as a component of auditory event-related potentials. The results show a clear MMN response only for normal hearing listeners and CI users with good performance, correlating with their logatome discrimination abilities. Higher discrimination scores for vowel-replacement paradigms than for the consonant-replacement paradigms were found. We conclude that the logatome discrimination test is well suited to monitor the speech perception skills of CI users. Due to the large number of available spoken logatome items, the Oldenburg Logatome Corpus appears to provide a useful and powerful basis for further development of speech perception tests for CI users.

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Discrimination of Stochastic Frequency Modulation by Cochlear Implant Users

Journal of the American Academy of Audiology ◽

10.3766/jaaa.14067 ◽

2015 ◽

Vol 26 (06) ◽

pp. 572-581 ◽

Cited By ~ 3

Author(s):

Stanley Sheft ◽

Min-Yu Cheng ◽

Valeriy Shafiro

Keyword(s):

Speech Perception ◽

Cochlear Implant ◽

Stimulus Duration ◽

Frequency Modulation ◽

Speech Intelligibility ◽

Signal To Noise Ratio ◽

Normal Hearing ◽

Signal To Noise ◽

Common Basis ◽

Low Rate

Background: Past work has shown that low-rate frequency modulation (FM) may help preserve signal coherence, aid segmentation at word and syllable boundaries, and benefit speech intelligibility in the presence of a masker. Purpose: This study evaluated whether difficulties in speech perception by cochlear implant (CI) users relate to a deficit in the ability to discriminate among stochastic low-rate patterns of FM. Research Design: This is a correlational study assessing the association between the ability to discriminate stochastic patterns of low-rate FM and the intelligibility of speech in noise. Study Sample: Thirteen postlingually deafened adult CI users participated in this study. Data Collection and Analysis: Using modulators derived from 5-Hz lowpass noise applied to a 1-kHz carrier, thresholds were measured in terms of frequency excursion both in quiet and with a speech-babble masker present, stimulus duration, and signal-to-noise ratio in the presence of a speech-babble masker. Speech perception ability was assessed in the presence of the same speech-babble masker. Relationships were evaluated with Pearson product–moment correlation analysis with correction for family-wise error, and commonality analysis to determine the unique and common contributions across psychoacoustic variables to the association with speech ability. Results: Significant correlations were obtained between masked speech intelligibility and three metrics of FM discrimination involving either signal-to-noise ratio or stimulus duration, with shared variance among the three measures accounting for much of the effect. Compared to past results from young normal-hearing adults and older adults with either normal hearing or a mild-to-moderate hearing loss, mean FM discrimination thresholds obtained from CI users were higher in all conditions. Conclusions: The ability to process the pattern of frequency excursions of stochastic FM may, in part, have a common basis with speech perception in noise. Discrimination of differences in the temporally distributed place coding of the stimulus could serve as this common basis for CI users.

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Noise‐suppression algorithms for improved speech intelligibility by normal‐hearing and cochlear implant listeners.

The Journal of the Acoustical Society of America ◽

10.1121/1.3384182 ◽

2010 ◽

Vol 127 (3) ◽

pp. 1815-1815

Author(s):

Philipos Loizou

Keyword(s):

Cochlear Implant ◽

Speech Intelligibility ◽

Noise Suppression ◽

Normal Hearing

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Effect of Synchronized Linked Band Selection on Speech Intelligibility of Bilateral Cochlear Implant Users

10.31234/osf.io/8zycu ◽

2020 ◽

Author(s):

Tom Gajęcki ◽

Waldo Nogueira

Keyword(s):

Electrical Stimulation ◽

Cochlear Implant ◽

Background Noise ◽

Speech Intelligibility ◽

Signal To Noise Ratio ◽

Normal Hearing ◽

Band Selection ◽

Signal To Noise ◽

Intelligibility Test ◽

Bilateral Cochlear Implant

Normal hearing listeners have the ability to exploit the audio input perceived by each ear to extract target information in challenging listening scenarios. Bilateral cochlear implant (BiCI) users, however, do not benefit as much as normal hearing listeners do from a bilateral input. In this study, we investigate the effect that bilaterally linked band selection, bilaterally synchronized electrical stimulation and ideal binary masks (IdBMs) have on the ability of 10 BiCIs to understand speech in background noise. The performance was assessed through a sentence-based speech intelligibility test, in a scenario where the speech signal was presented from the front and the interfering noise from one side. The linked band selection relies on the most favorable signal-to-noise-ratio (SNR) ear, which will select the bands to be stimulated for both CIs. Results show that no benefit from adding a second CI to the most favorable SNR side was achieved for any of the tested bilateral conditions. However, when using both devices, speech perception results show that performing linked band selection, besides delivering bilaterally synchronized electrical stimulation, leads to an improvement compared to standard clinical setups. Moreover, the outcomes of this work show that by applying IdBMs, subjects achieve speech intelligibility scores similar to the ones without background noise.

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

American Journal of Audiology ◽

10.1044/1059-0889(2002/013) ◽

2002 ◽

Vol 11 (2) ◽

pp. 124-127 ◽

Cited By ~ 32

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.

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Late development of the categorical perception of speech sounds in pre-adolescent children

ZAS Papers in Linguistics ◽

10.21248/zaspil.42.2005.271 ◽

2005 ◽

Vol 42 ◽

pp. 13-31

Author(s):

Victoria Medina ◽

Willy Serniclaes

Keyword(s):

Cochlear Implant ◽

Speech Intelligibility ◽

Categorical Perception ◽

Normal Hearing ◽

Deaf Children ◽

First Year ◽

Functional Implications ◽

Concomitant Reduction ◽

Phonetic Features ◽

Hearing Children

While the perilinguistic child is endowed with predispositions for the categorical perception of phonetic features, their adaptation to the native language results from a long evolution from the end of the first year of age up to the adolescence. This evolution entails both a better discrimination between phonological categories, a concomitant reduction of the discrimination between within-category variants, and a higher precision of perceptual boundaries between categories. The first objective of the present study was to assess the relative importance of these modifications by comparing the perceptual performances of a group of 11 children, aged from 8 to 11 years, with those of their mothers. Our second objective was to explore the functional implications of categorical perception by comparing the performances of a group of 8 deaf children, equipped with a cochlear implant, with normal-hearing chronological age controls. The results showed that the categorical boundary was slightly more precise and that categorical perception was consistently larger in adults vs. normal-hearing children. Those among the deaf children who were able to discriminate minimal distinctions between syllables displayed categorical perception performances equivalent to those of normal-hearing controls. In conclusion, the late effect of age on the categorical perception of speech seems to be anchored in a fairly mature phonological system, as evidenced the fairly high precision of categorical boundaries in pre-adolescents. These late developments have functional implications for speech perception in difficult conditions as suggested by the relationship between categorical perception and speech intelligibility in cochlear implant children.

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Speech Intelligibility for Cochlear Implant Users with the MMSE Noise-Reduction Time-Frequency Mask

Biomedical Signal Processing and Control ◽

10.1016/j.bspc.2020.101982 ◽

2020 ◽

Vol 60 ◽

pp. 101982

Author(s):

Gustavo Leão Mourão ◽

Márcio Holsbach Costa ◽

Stephan Paul

Keyword(s):

Cochlear Implant ◽

Noise Reduction ◽

Speech Intelligibility ◽

Time Frequency ◽

Reduction Time

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Cochlear implant-related speech processing may diminish the advantage of exposure to infant-directed speech

10.1101/2020.06.29.20140319 ◽

2020 ◽

Author(s):

Meisam K. Arjmandi ◽

Derek Houston ◽

Yuanyuan Wang ◽

Laura C. Dilley

Keyword(s):

Individual Differences ◽

Cochlear Implant ◽

Language Learning ◽

Cochlear Implants ◽

Speech Processing ◽

Speech Intelligibility ◽

Normal Hearing ◽

Considerable Variability ◽

Female Adult ◽

Speaking Style

ABSTRACTCaregivers modify their speech when talking to infants, a specific type of speech known as infant-directed speech (IDS). This speaking style facilitates language learning compared to adult-directed speech (ADS) in infants with normal hearing (NH). While infants with NH and those with cochlear implants (CIs) prefer listening to IDS over ADS, it is yet unknown how CI speech processing may affect the acoustic distinctiveness between ADS and IDS, as well as the degree of intelligibility of these. This study analyzed speech of seven female adult talkers to investigate the effects of simulated CI speech processing on (1) acoustic distinctiveness between ADS and IDS, (2) estimates of intelligibility of caregivers’ speech in ADS and IDS, and (3) individual differences in caregivers’ ADS-to-IDS modification and speech intelligibility. Results suggest that CI speech processing is substantially detrimental to the acoustic distinctiveness between ADS and IDS, as well as to the intelligibility benefit derived from ADS-to-IDS modifications. Moreover, the observed considerable variability across individual talkers in acoustic implementation of ADS-to-IDS modification and speech intelligibility was significantly reduced due to CI speech processing. The findings are discussed in the context of the link between IDS and language learning in infants with CIs.

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