Optimization of Speech Processor Fitting Strategies for Chinese‐Speaking Cochlear Implantees

Sun, John C.; Skinner, Margaret W.; Liu, S. Y.; Wang, Frances N.M.; Huang, Tsun‐Sheng; Lin, Tay-Jyi

doi:10.1097/00005537-199804000-00018

Cited by 17 publications

(11 citation statements)

References 7 publications

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“…No mention was made of reducing the C-levels to compensate for loudness summation across electrodes so that loud sounds in everyday life were not too loud or irritating, or of increasing T-levels if the overall level of conversational speech was too soft with appropriate sensitivity control settings. Clinical research with Nucleus 22 and 24 devices in the Cochlear Implant Program at Washington University School of Medicine (WUSM) has shown the importance of setting appropriate T-and C-levels for maximizing speech recognition for soft to loud input levels (Holden, Skinner, Holden, & Demorest, 2002;Skinner, Arndt, & Staller, 2002;Skinner, Holden, Demorest, & Holden, 1995;Skinner, Holden, Holden, & Demorest, 1999;Skinner, Holden, Whitford, Plant, Psarros, & Holden, 2002;and Sun, Skinner, Liu, Wang, Huang, & Lin, 1998). Based on these findings, a specific goal for clinical fittings has been to optimize audibility of soft to loud speech so that the cochlear implant recipients can understand speech spoken in many listening situations (e.g., spoken within three feet, from across a room, on the telephone).…”

Section: Conclusion: the Results Of This Study Provide Important Insmentioning

confidence: 99%

Relation Between Neural Response Telemetry Thresholds, T- and C-Levels, and Loudness Judgments in 12 Adult Nucleus 24 Cochlear Implant Recipients

Potts¹,

Skinner²,

Gotter³

et al. 2007

Ear &Amp; Hearing

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The results of this study provide important insight into the relation between NRT thresholds and loudness judgments for different stimulation rates and T- and C-levels at various MAP rates. The loudness judgment dynamic range and MAP dynamic range (T- and C-levels) varied notably for different stimulation rates. As a result, the relation of NRT thresholds to these measures also varied with stimulation rate. Overall, the mean vNRT thresholds fell higher in the loudness judgment dynamic range than the tNRT thresholds. Mean NRT thresholds fell between the judgments of medium soft and maximum acceptable loudness for all stimulation rates. Mean vNRT thresholds fell above C-levels, whereas almost half of tNRT thresholds fell just below C-levels. However, the relation between NRT thresholds and C-levels varied substantially for different MAP stimulation levels. In addition, there is substantial individual variability in the relation between NRT thresholds and MAP levels that is not reflected in the group data. The prediction of the contour of T- and C-levels from the contour of NRT thresholds across electrodes would not be appropriate for half of the subjects. Therefore, great care should be taken when applying a fitting rule that incorporates NRT thresholds without considering these individual differences. For adults who can provide appropriate loudness judgments and threshold responses it appears to be most efficient to primarily use behavioral measures to create MAPs.

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Section: Conclusion: the Results Of This Study Provide Important Insmentioning

confidence: 99%

Relation Between Neural Response Telemetry Thresholds, T- and C-Levels, and Loudness Judgments in 12 Adult Nucleus 24 Cochlear Implant Recipients

Potts¹,

Skinner²,

Gotter³

et al. 2007

Ear &Amp; Hearing

Self Cite

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“…Skinner and her colleagues (Skinner, Holden, Holden, & Demorest, 1995;Sun, Skinner, Liu, Wang, Huang, & Lin, 1998;Skinner, Holden, Holden, & Demorest, 1999) have shown that the specific procedures used to set minimum and maximum electrical stimulation levels can also affect implant listeners' ability to hear soft speech. Skinner et al (1999) compared the use of thresholds versus raised levels of minimum stimulation in eight Nucleus 22 users with the SPEAK strategy.…”

Section: Discussionmentioning

confidence: 99%

“…These findings indicate that minimum electrical stimulation levels should be set above regions of slow loudness growth that may exist near threshold. In other work, this group has demonstrated the importance of optimizing maximum electrical stimulation levels to make conversational speech comfortably loud when the speech processor is set at a moderate sensitivity control setting, and to avoid distortion of loud sounds (Skinner et al, 1995;Sun et al, 1998;Seligman & Whitford, 1995). As discussed later, the ability to make optimal use of higher sensitivity settings to perceive soft speech depends on the use of appropriate maximum stimulation levels.…”

Section: Discussionmentioning

confidence: 99%

Effects of Presentation Level on Phoneme and Sentence Recognition in Quiet by Cochlear Implant Listeners

Donaldson

Allen

2003

Ear and Hearing

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Objective: The objectives of this study were to characterize the effects of presentation level on speech recognition in quiet by cochlear implant users with the Nucleus 22 SPEAK and Clarion v1.2 CIS speechprocessing strategies, and to relate speech recognition at low presentation levels to stimulus audibility as measured by sound field thresholds. It was hypothesized that speech recognition performance in both Nucleus SPEAK and Clarion CIS participants would decrease as presentation level was decreased below 50 to 60 dBA, due to audibility limitations. However, it was expected that such level effects would be less severe in CIS participants than in SPEAK participants because the Clarion v1.2 device encodes a wider acoustic dynamic range (up to 60 dB) than the Nucleus 22 device (30 dB).Design: Performance-intensity (P-I) functions for vowels, consonants and sentences in quiet were obtained from each participant. P-I functions incorporated speech levels of 70, 60, 50, 40 and 30 dBA. Subjects used their clinical speech processor maps and adjusted the loudness (volume/sensitivity) controls on their processors so that speech presented at 60 dBA was comfortably loud. Maps were created using default clinical procedures and were not adjusted to optimize sound field thresholds. Sound field thresholds and dynamic ranges were measured for warbled pure tones with frequencies of 250 to 6000 Hz.Results: Consonant and sentence recognition showed strong level effects for both SPEAK and CIS participants, with performance decreasing substantially at levels below 50 dBA in most individuals. Vowel recognition showed weaker level effects. For all three speech materials, SPEAK and CIS participants demonstrated similar mean performance at 70 dBA; however, SPEAK participants showed larger reductions in performance than CIS participants with decreasing level. Sound field thresholds were more sensitive for CIS participants than for SPEAK participants, supporting the hypothesis that performance differences were related to audibility. Conclusions:Cochlear implant listeners are unable to maintain good speech recognition at low presentation levels due to reduced stimulus audibility, and this may significantly limit their ability to communicate in daily life. It is likely that audibility differences between SPEAK and CIS participants in the present study can be attributed at least partly to differences in the acoustic dynamic range used by the respective processors. However, several additional factors may have contributed to differences in audibility and perception of soft speech among individual listeners with both devices. These include the minimum and maximum electrical stimulation levels specified in participants' maps and the speech processor sensitivity setting used for testing.

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“…Another problem that cochlear-implant patients face is poor perception of tonal information. This results in a diminished enjoyment of music (e.g., Fujita and Ito, 1999;Gfeller et al, 2002Gfeller et al, , 2007Kong et al, 2004;see also McDermott, 2004 for a review) and it is a major problem for people who speak tone languages (Zeng, 1995;Huang et al, 1995Huang et al, , 1996Sun et al, 1998;Wei et al, 2000Wei et al, , 2004Wei et al, , 2007Lee et al, 2002;Ciocca et al, 2002;Wong and Wong, 2004). The problem with music and lexical tone perception in cochlear implant users appears to stem from the same mechanism, that is, a limited number of spectral channels and a lack of encoding of fine structure information in the current implant systems (Smith et al, 2002;Xu and Pfingst, 2003).…”

Section: Introductionmentioning

confidence: 99%

Spectral and temporal cues for speech recognition: Implications for auditory prostheses

Pfingst

2008

Hearing Research

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Features of stimulation important for speech recognition in people with normal hearing and in people using implanted auditory prostheses include spectral information represented by place of stimulation along the tonotopic axis and temporal information represented in low-frequency envelopes of the signal. The relative contributions of these features to speech recognition and their interactions have been studied using vocoder-like simulations of cochlear implant speech processors presented to listeners with normal hearing. In these studies, spectral/place information was manipulated by varying the number of channels and the temporal-envelope information was manipulated by varying the lowpass cutoffs of the envelope extractors. Consonant and vowel recognition in quiet reached plateau at 8 and 12 channels and lowpass cutoff frequencies of 16 Hz and 4 Hz, respectively. Phoneme (especially vowel) recognition in noise required larger numbers of channels. Lexical tone recognition required larger numbers of channels and higher lowpass cutoff frequencies. There was a tradeoff between spectral/place and temporal-envelope requirements. Most current auditory prostheses seem to deliver adequate temporal-envelope information but the number of effective channels is suboptimal, particularly for speech recognition in noise, lexical tone recognition and music perception.

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Optimization of Speech Processor Fitting Strategies for Chinese‐Speaking Cochlear Implantees

Cited by 17 publications

References 7 publications

Relation Between Neural Response Telemetry Thresholds, T- and C-Levels, and Loudness Judgments in 12 Adult Nucleus 24 Cochlear Implant Recipients

Relation Between Neural Response Telemetry Thresholds, T- and C-Levels, and Loudness Judgments in 12 Adult Nucleus 24 Cochlear Implant Recipients

Effects of Presentation Level on Phoneme and Sentence Recognition in Quiet by Cochlear Implant Listeners

Spectral and temporal cues for speech recognition: Implications for auditory prostheses

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