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An Undecimated Wavelet-based Method for Cochlear Implant Speech Processing.

Hajiaghababa F, Kermani S, Marateb HR - J Med Signals Sens (2014)

Bottom Line: The undecimated wavelet packet transform (UWPT) is computed like the wavelet packet transform except that it does not down-sample the output at each level.The statistical analysis revealed that the UWT-based N-of-M strategy significantly improved the MOS, STOI and segmental SNR (P < 0.001) compared with what obtained with the IIR filter-bank based strategies.Thus, the information loss is minimal and that is why the UWPT performance was better than that of traditional filter-bank strategies in speech recognition tests.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.

ABSTRACT
A cochlear implant is an implanted electronic device used to provide a sensation of hearing to a person who is hard of hearing. The cochlear implant is often referred to as a bionic ear. This paper presents an undecimated wavelet-based speech coding strategy for cochlear implants, which gives a novel speech processing strategy. The undecimated wavelet packet transform (UWPT) is computed like the wavelet packet transform except that it does not down-sample the output at each level. The speech data used for the current study consists of 30 consonants, sampled at 16 kbps. The performance of our proposed UWPT method was compared to that of infinite impulse response (IIR) filter in terms of mean opinion score (MOS), short-time objective intelligibility (STOI) measure and segmental signal-to-noise ratio (SNR). Undecimated wavelet had better segmental SNR in about 96% of the input speech data. The MOS of the proposed method was twice in comparison with that of the IIR filter-bank. The statistical analysis revealed that the UWT-based N-of-M strategy significantly improved the MOS, STOI and segmental SNR (P < 0.001) compared with what obtained with the IIR filter-bank based strategies. The advantage of UWPT is that it is shift-invariant which gives a dense approximation to continuous wavelet transform. Thus, the information loss is minimal and that is why the UWPT performance was better than that of traditional filter-bank strategies in speech recognition tests. Results showed that the UWPT could be a promising method for speech coding in cochlear implants, although its computational complexity is higher than that of traditional filter-banks.

No MeSH data available.


Related in: MedlinePlus

Comparison of short-time objective intelligibility for undecimated wavelet, and infinite impulse response filter-bank, both with N-of-M, implementations
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Figure 3: Comparison of short-time objective intelligibility for undecimated wavelet, and infinite impulse response filter-bank, both with N-of-M, implementations

Mentions: The other objective measure of speech quality, the STOI, was used for comparing both methods implementations. Figure 3 shows the results in terms of the STOI for undecimated wavelet and IIR filter-bank based N-of-M strategy. The STOI values for the undecimated wavelet and the IIR filter-bank N-of-M implementations were 0.76 ± 0.03 and 0.65 ± 0.04, respectively.


An Undecimated Wavelet-based Method for Cochlear Implant Speech Processing.

Hajiaghababa F, Kermani S, Marateb HR - J Med Signals Sens (2014)

Comparison of short-time objective intelligibility for undecimated wavelet, and infinite impulse response filter-bank, both with N-of-M, implementations
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4236803&req=5

Figure 3: Comparison of short-time objective intelligibility for undecimated wavelet, and infinite impulse response filter-bank, both with N-of-M, implementations
Mentions: The other objective measure of speech quality, the STOI, was used for comparing both methods implementations. Figure 3 shows the results in terms of the STOI for undecimated wavelet and IIR filter-bank based N-of-M strategy. The STOI values for the undecimated wavelet and the IIR filter-bank N-of-M implementations were 0.76 ± 0.03 and 0.65 ± 0.04, respectively.

Bottom Line: The undecimated wavelet packet transform (UWPT) is computed like the wavelet packet transform except that it does not down-sample the output at each level.The statistical analysis revealed that the UWT-based N-of-M strategy significantly improved the MOS, STOI and segmental SNR (P < 0.001) compared with what obtained with the IIR filter-bank based strategies.Thus, the information loss is minimal and that is why the UWPT performance was better than that of traditional filter-bank strategies in speech recognition tests.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran.

ABSTRACT
A cochlear implant is an implanted electronic device used to provide a sensation of hearing to a person who is hard of hearing. The cochlear implant is often referred to as a bionic ear. This paper presents an undecimated wavelet-based speech coding strategy for cochlear implants, which gives a novel speech processing strategy. The undecimated wavelet packet transform (UWPT) is computed like the wavelet packet transform except that it does not down-sample the output at each level. The speech data used for the current study consists of 30 consonants, sampled at 16 kbps. The performance of our proposed UWPT method was compared to that of infinite impulse response (IIR) filter in terms of mean opinion score (MOS), short-time objective intelligibility (STOI) measure and segmental signal-to-noise ratio (SNR). Undecimated wavelet had better segmental SNR in about 96% of the input speech data. The MOS of the proposed method was twice in comparison with that of the IIR filter-bank. The statistical analysis revealed that the UWT-based N-of-M strategy significantly improved the MOS, STOI and segmental SNR (P < 0.001) compared with what obtained with the IIR filter-bank based strategies. The advantage of UWPT is that it is shift-invariant which gives a dense approximation to continuous wavelet transform. Thus, the information loss is minimal and that is why the UWPT performance was better than that of traditional filter-bank strategies in speech recognition tests. Results showed that the UWPT could be a promising method for speech coding in cochlear implants, although its computational complexity is higher than that of traditional filter-banks.

No MeSH data available.


Related in: MedlinePlus