Binaural sound coding strategies can improve speech intelligibility for cochlear implant (CI) users. These require a signal transmission between two CIs. As power consumption needs to be kept low in CIs, efficient cod...
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ISBN:
(纸本)9781538613115
Binaural sound coding strategies can improve speech intelligibility for cochlear implant (CI) users. These require a signal transmission between two CIs. As power consumption needs to be kept low in CIs, efficient coding or bit-rate reduction of the signals is necessary. In this work, it is proposed to code the electrical signals or excitation patterns (EP) of the CI instead of the audio signals captured by the microphones. For this purpose we designed a differential pulse code modulation based codec with zero algorithmic delay to code the EP of the advanced combination encoder (ACE) sound coding strategy for CIs. Our EP codec was compared to the G.722 64 kbit/s audio codec using the signal-to-noise ratio (SNR) as objective measure of quality. On two audio-sets the mean SNR was 0.5 to 13.9 dB higher when coding the EP with the proposed coding method while achieving a mean bit-rate between 34.1 and 40.3 kbit/s.
This paper presents the real-time implementation of wavelet-based advanced combination encoder on PDA platforms for cochlear implant studies. Three real-time implementations using the conventional FFT, our previous re...
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ISBN:
(纸本)9781424442966
This paper presents the real-time implementation of wavelet-based advanced combination encoder on PDA platforms for cochlear implant studies. Three real-time implementations using the conventional FFT, our previous recursive DFT, and the wavelet transform are compared in terms of computational complexity, processing time and fixed-point accuracy. The results obtained show that this new real-time implementation on PDA platforms is computationally comparable to our previous real-time recursive DFT implementation while achieving a higher accuracy or a lower quantization error.
This paper presents the real-time implementation of wavelet-based advanced combination encoder on PDA platforms for cochlear implant studies. Three real-time implementations using the conventional FFT, our previous re...
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ISBN:
(纸本)9781424442959
This paper presents the real-time implementation of wavelet-based advanced combination encoder on PDA platforms for cochlear implant studies. Three real-time implementations using the conventional FFT, our previous recursive DFT, and the wavelet transform are compared in terms of computational complexity, processing time and fixed-point accuracy. The results obtained show that this new real-time implementation on PDA platforms is computationally comparable to our previous real-time recursive DFT implementation while achieving a higher accuracy or a lower quantization error.
Cochlear implant (CI) recipients require alternative signal processing for speech enhancement, since the quantities needed for intelligibility and quality improvement differ significantly when direct stimulation of th...
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ISBN:
(纸本)9781479928934
Cochlear implant (CI) recipients require alternative signal processing for speech enhancement, since the quantities needed for intelligibility and quality improvement differ significantly when direct stimulation of the basilar membrane is employed for CIs. Here, a robust feature vector is proposed for environment classification in CI devices. The feature vector is directly computed from the output of the advanced combination encoder (ACE), which is a sound coding strategy commonly used in CIs. Performance of the proposed feature vector is evaluated in the context of environment classification tasks under anechoic quiet, noisy, reverberant, and noisy reverberant conditions. Speech material taken from the IEEE corpus are used to simulate different environmental acoustic conditions with: 1) three measured room impulse responses (RIR) with distinct reverberation times (T-60) for generating reverberant environments, and 2) car, train, white Gaussian, multi-talker babble, and speech-shaped noise (SSN) samples for creating noisy conditions at 4 different signal-to-noise ratio (SNR) levels. We investigate 3 different classifiers for environment detection, namely Gaussian mixture models (GMM), support vector machines (SVM), and neural networks (NN). Experimental results illustrate the effectiveness of the proposed features for environment classification.
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