Mandarin tone recognition in cochlear-implant subjects

Wei, Chaogang; Cao, Keli; Zeng, Fan‐Gang

doi:10.1016/j.heares.2004.06.002

Cited by 109 publications

(86 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mandarin, for example, has four tone patterns; Cantonese has six. Mean scores on tests of recognition of the tone patterns for Mandarin average between 50 and 70% correct (e.g., Wei et al, 2004). More than a quarter of the world's population uses tone languages (e.g., Zeng, 1995), so relatively low scores like those just cited are a potentially-important problem.…”

Section: Performance With Present-day Unilateral Implantsmentioning

confidence: 99%

Cochlear implants: A remarkable past and a brilliant future

2008

View full text Add to dashboard Cite

The aims of this paper are to (i) provide a brief history of cochlear implants; (ii) present a status report on the current state of implant engineering and the levels of speech understanding enabled by that engineering; (iii) describe limitations of current signal processing strategies and (iv) suggest new directions for research. With current technology the "average" implant patient, when listening to predictable conversations in quiet, is able to communicate with relative ease. However, in an environment typical of a workplace the average patient has a great deal of difficulty. Patients who are "above average" in terms of speech understanding, can achieve 100% correct scores on the most difficult tests of speech understanding in quiet but also have significant difficulty when signals are presented in noise. The major factors in these outcomes appear to be (i) a loss of low-frequency, fine structure information possibly due to the envelope extraction algorithms common to cochlear implant signal processing; (ii) a limitation in the number of effective channels of stimulation due to overlap in electric fields from electrodes, and (iii) central processing deficits, especially for patients with poor speech understanding. Two recent developments, bilateral implants and combined electric and acoustic stimulation, have promise to remediate some of the difficulties experienced by patients in noise and to reinstate low-frequency fine structure information. If other possibilities are realized, e.g., electrodes that emit drugs to inhibit cell death following trauma and to induce the growth of neurites toward electrodes, then the future is very bright indeed.

show abstract

Section: Performance With Present-day Unilateral Implantsmentioning

confidence: 99%

Cochlear implants: A remarkable past and a brilliant future

2008

View full text Add to dashboard Cite

show abstract

“…Wei et al (2004) tested tone recognition in five Nucleus-22 users and showed a clear dependence of tone recognition on number of channels. The performance improved from about 30% correct with one channel to about 70% correct with ten channels and reached plateau at ten channels.…”

Section: Spectral and Temporal Cues For Lexical-tone Recognitionmentioning

confidence: 99%

“…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

View full text Add to dashboard Cite

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.

show abstract

“…A clear dichotomy was observed in which the implant subjects were able to recognize most vowels (about 70% correct), but not the speakers who produced these vowels (about 20% correct). The second experiment compared the performance of Mandarin tone recognition as a function of the number of spectral bands (Kong et al, presented at the 2003 ARO meeting) and a function of the number of electrodes in 4 Nucleus native-Mandarin speakers (Wei et al, 1999;Wei et al, 2004). Figure 15 shows that the normal-hearing subjects were able to use the envelope cue effectively, even with 1 band, producing 70% to 80% correct performance Xu et al, 2002), whereas the cochlear-implant subjects performed at chance with 1 electrode.…”

Section: Speaker and Tone Recognitionmentioning

confidence: 99%

Trends in Cochlear Implants

Zeng

2004

Trends in Amplification

Self Cite

320

238

View full text Add to dashboard Cite

More than 60,000 people worldwide use cochlear implants as a means to restore functional hearing. Although individual performance variability is still high, an average implant user can talk on the phone in a quiet environment. Cochlear-implant research has also matured as a field, as evidenced by the exponential growth in both the patient population and scientific publication. The present report examines current issues related to audiologic, clinical, engineering, anatomic, and physiologic aspects of cochlear implants, focusing on their psychophysical, speech, music, and cognitive performance. This report also forecasts clinical and research trends related to presurgical evaluation, fitting protocols, signal processing, and postsurgical rehabilitation in cochlear implants. Finally, a future landscape in amplification is presented that requires a unique, yet complementary, contribution from hearing aids, middle ear implants, and cochlear implants to achieve a total solution to the entire spectrum of hearing loss treatment and management. Trends in Cochlear ImplantsFan-Gang Zeng, PhD IntroductionCochlear implants are the only medical intervention that can restore partial hearing to a totally deafened person via electric stimulation of the residual auditory nerve. Twenty years ago, the cochlear implant started as a single-electrode device that was used mainly for enhancing lipreading and providing sound awareness. Today, it is a sophisticated multielectrode device that allows most of its 60,000 users to talk on the phone. The implant candidacy has been expanded to include children as young as 3 months and adults who have significant functional residual hearing, particularly at low frequencies. Commercial and research enterprises have also matured to generate annual revenues of hundreds of millions of dollars and to command attention from multidisciplinary fields including engineering, medicine, and neuroscience.This review describes what a cochlear implant is and how it works, and discusses its past, present, and future. It also focuses on audiologic and clinical issues, engineering issues, anatomic and physiologic issues, and cochlear-implant performance in basic psychophysics, speech, music, and cognition. Finally, trends in cochlear implants from clinical, research, and system points of view are presented. History of Cochlear ImplantsDevelopment of cochlear implants can be traced back at least 200 years to the Italian scientist Alessandro Volta, who invented the battery (the unit volt was named after him). He used the battery as a research tool to demonstrate that electric stimulation could directly evoke auditory, visual, olfactory, and touch sensations in humans (Volta, 1800). When placing one of the two ends of a 50-volt battery in each of his ears, he observed that ". . . at the moment when the circuit was completed, I received a shock in the head, and some moments after I began to hear a sound, or rather noise in the ears, which I cannot well define: it was a kind of crackling with shocks, as if some paste...

show abstract

Mandarin tone recognition in cochlear-implant subjects

Cited by 109 publications

References 38 publications

Cochlear implants: A remarkable past and a brilliant future

Cochlear implants: A remarkable past and a brilliant future

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

Trends in Cochlear Implants

Contact Info

Product

Resources

About