Haengwoo Lee
Namseoul university, Korea

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Blind Signal Separation Algorithm for Acoustic Echo Cancellation Haengwoo Lee
Indonesian Journal of Electrical Engineering and Informatics (IJEEI) Vol 6, No 3: September 2018
Publisher : IAES Indonesian Section

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52549/ijeei.v6i3.583

Abstract

This paper is to the blind signal separation algorithm applied to acoustic echo cancellation. This algorithm doesn’t degrade the performance of echo cancellation even in the double-talk. In the closed echo environment, the mixing model of acoustic signals has multi-channel, so the convolutive blind signal separation method is applied. And the mixing coefficients are computed by using the feedback model without directly calculating the separation coefficients. The coefficient updating is performed by iterative computations based on the second-order statistical properties, thus estimating the near-end speech. Many simulations have been performed to verify the performance of the proposed blind signal separation. Simulation results show that the proposed acoustic echo canceller operates safely regardless of double-talk, and the PESQ is improved by 0.6 point compared with the general adaptive FIR filter structure.
Double-talk robust acoustic echo canceller based on CNN filter Haengwoo Lee
Indonesian Journal of Electrical Engineering and Informatics (IJEEI) Vol 8, No 1: March 2020
Publisher : IAES Indonesian Section

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (626.122 KB) | DOI: 10.52549/ijeei.v8i1.1070

Abstract

Conventional acoustic echo cancellation works by using an adaptive algorithm to identify the impulse response of the echo path. In this paper, we use the CNN neural network filter to remove the echo signal from the microphone input signal, so that only the speech signal is transmitted to the far-end. Using the neural network filter, weights are well converged by the general speech signal. Especially it shows the ability to perform stable operation without divergence even in the double-talk state, in which both parties speak simultaneously. As a result of simulation, this system showed superior performance and stable operation compared to the echo canceller of the adaptive filter structure.
Noise reduction system by using CNN deep learning model Haengwoo Lee
Indonesian Journal of Electrical Engineering and Informatics (IJEEI) Vol 9, No 1: March 2021
Publisher : IAES Indonesian Section

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52549/ijeei.v9i1.2494

Abstract

In this paper, we propose a new algorithm to reduce the acoustic noise of hearing aids. This algorithm improves the noise reduction performance by the deep learning algorithm using the neural network adaptive prediction filter instead of the existing adaptive filter. The speech is estimated from a single input speech signal containing noise using a 80-neuron, 16-filter convolutional neural network(CNN) filter and an error backpropagation algorithm. This is by using the quasi-periodic property of the voiced section in the speech signal, and it is possible to predict the speech more effectively by applying the repeated pitch. In order to verify the performance of the noise reduction system proposed in this research, a simulation program using Tensorflow and Keras libraries was coded and a simulation was done. As a result of the experiment, the proposed deep learning model improves the mean square error(MSE) of 28.5% compared to using the existing adaptive filter and 17.2% compared to using the FNN(full-connected neural network) filter.
Analysis on performances of the optimization algorithms in CNN speech noise attenuator Haengwoo Lee
Indonesian Journal of Electrical Engineering and Informatics (IJEEI) Vol 9, No 4: December 2021
Publisher : IAES Indonesian Section

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52549/ijeei.v9i4.3245

Abstract

In this paper, we studied the effect of the optimization algorithm of weight coefficients on the performance of the CNN(Convolutional Neural Network) noise attenuator. This system improves the performance of the noise attenuation by a deep learning algorithm using the neural network adaptive predictive filter instead of using the existing adaptive filter. Speech is estimated from a single input speech signal containing noise using 64-neuron, 16-filter CNN filters and an error back propagation algorithm. This is to use the quasi-periodic nature of the voiced sound section of the voice signal. In this study, to verify the performance of the noise attenuator for the optimization, a test program using the Keras library was written and training was performed. As a result of simulation, this system showed the smallest MSE value when using the Adam algorithm among the Adam, RMSprop, and Adagrad optimization algorithms, and the largest MSE value in the Adagrad algorithm. This is because the Adam algorithm requires a lot of computation but it has an exellent ability to estimate the optimal value by using the advantages of RMSprop and Momentum SGD.