• The Journal of the Acoustical Society of Korea
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• v.33 no.2
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• pp.139-145
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• 2014

In this paper, a feature parameter is obtained by applying the Teager energy to the WPD(Wavelet Packet Decomposition) coefficients. The threshold value is obtained based on means and standard deviations of nonspeech frames. Experimental results by using TIMIT speech and NOISEX-92 noise databases show that the proposed algorithm is superior to the typical VAD algorithm. The ROC(Receiver Operating Characteristics) curves are used to compare performance of VAD's for SNR values of ranging from 10 to -10 dB.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.1
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• pp.58-63
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• 2010

In this paper, we propose a simple technique for the detection of a frequency jump in the GPS clock behavior. GPS satellite atomic clocks have characteristics of a second order polynomial in the long term and a non-periodic frequency drift in the short term, showing a sudden frequency jump occasionally. As satellite clock anomalies influence on GPS measurements, it requires to develop a real time technique for the detection of the clock anomaly on the real-time GPS precise point positioning. The proposed technique is based on Teager energy which is mainly used in the field of various signal processing for the detection of a specific signal or symptom. Therefore, we employed the Teager energy for the detection of the jump phenomenon of GPS satellite atomic clocks, and it showed that the proposed clock anomaly detection strategy outperforms a conventional detection methodology.

• The Journal of the Acoustical Society of Korea
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• v.30 no.7
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• pp.396-401
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• 2011

In this paper, we propose a novel voice activity detection (VAD) algorithm to effectively distinguish speech from nonspeech in various noisy environments. The presented VAD utilizes the power spectral deviation (PSD) based on Teager energy (TE) instead of the conventional PSD scheme to improve the performance of decision for speech segments. In addition, the speech absence probability (SAP) is derived in each frequency subband to modify the PSD for further VAD. Performances of the proposed VAD algorithm are evaluated by objective test under various environments and better results compared with the conventional methods are obtained.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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• pp.407-410
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• 1998

본 논문에서는 변형된 Teager 에너지를 이용하여 음성의 끝점을 검출하는 알고리듬을 제안하였다. 기존의 방법에서는 대부분 음성신호의 에너지와 영교차율을 이용하거나 이 파라미터들과 함께 다른 여러 파라미터들을 사용하여 끝점을 검출하였다. 여러 파라미터들을 사용하는 알고리듬의 경우 계산량이 많아지게 되는데, 이에 비해 본 논문에서는 하나의 파라미터를 이용하기 때문에 계산량이 기존의 알고리듬보다 적다. 그리고 이 알고리듬에서 사용한 변형된 Teager 에너지는 음성신호의 진폭뿐만 아니라 주파수까지 고려한 파라미터이다. 일반적으로 마찰음은 진폭이 작아 검출하기가 어려운데, 본 논문에서는 이러한 마찰음에 대해 실험을 했고, 그 결과를 통해 제안한 알고리듬이 기존의 다른 여러 알고리듬보다 성능이 우수하다는 것을 확인할 수 있었다.

• The Journal of the Acoustical Society of Korea
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• v.34 no.4
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• pp.310-315
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• 2015

A single channel VAD (Voice Activity Detection) algorithm for nonstationary noise environment is proposed in this paper. Threshold values of the feature parameter for VAD decision are updated adaptively based on estimates of means and standard deviations of past non-speech frames. The feature parameter, SPD-TE (Spectral Power Difference-Teager Energy), is obtained by applying the Teager energy to the WPD (Wavelet Packet Decomposition) coefficients. It was reported previously that the SPD-TE is robust to noise as a feature for VAD. Experimental results by using TIMIT speech and NOISEX-92 noise databases show that decision accuracy of the proposed algorithm is comparable to several typical VAD algorithms including standards for SNR values ranging from 10 to -10 dB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.11
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• pp.2470-2476
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• 1997

We propose a simle scheme for detecting tone signals narrowly spaced in the frequency by employing a nonlinear device called Teager's energy tracker. When the input signal is a tone signal, the output of Teager's energy tracker is proportional to the energy and tone frequency of the input signal. When the envelope of the input tone is varying, this tracker can also track the energy of the envelope. By employing Teager's algorithm as a preprocessor, the detector for narrowly spaced tone signals can be implemented without the use of sharp notch filters. As an example, the proposed detector is applied to distinguishing ITU-T V.8 and V.25 tone signals. The detector perfodrmance is analyszed and is verified by computer simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9B
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• pp.1563-1569
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• 2000

Teager-Kaiser algorithm that can track the energy of tone signals with simple nonlinear operations, has been applied to detection of tone signals closely spaced in frequency. The performance of the previous detector depends upon the performance of internal filters. An improved scheme is proposed in this paper by employing the nonlinear energy trackers in cascade. The proposed detector is analytically designed and verified by computer simulation. It shows that the new detection scheme improves the detection performance while reducing the implementation complexity.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.3
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• pp.81-88
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• 2012

In this paper, we propose a novel speech enhancement algorithm for effective noise suppression in various noisy environments. In the proposed method, to result in improved decision performance for speech and noise segments, local speech absence probability (LSAP, local SAP) based on Teager energy of noisy speech is used as the feature parameter for voice activity detection (VAD) in each frequency subband instead of conventional LSAP. In addition, The presented method utilizes global SAP (GSAP) derived in each frame as the weighting parameter for the modification of the adopted TE operator to improve the performance of TE operator. Performances of the proposed algorithm are evaluated by objective test under various environments and better results compared with the conventional methods are obtained.

• The Journal of the Acoustical Society of Korea
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• v.16 no.2
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• pp.41-48
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• 1997

This paper proposes the methods for improving the recognition rate of theARS, especially equipped with the speech recognition capability. Telephone speech, which is the input to the ARS, is usually affected by the announcements from the system, channel noise, and channel distortion, thus directly applying the recognition algorithm developed for clean speech to the noisy telephone speech will bring the significant performance degradation. To cope with this problem, this paper proposes three methods: 1)the accurate detection of the inputting instant of the speech in order to immediately turn off the announcements from the system at that instant, 2)the effective end-point detection of the noisy telephone speech on the basis of Teager energy, and 3)the SDCN-based compensation of the channel distortion. Experiments on speaker-independent, noisy telephone speech reveal that the combination of the above three proposed methods provides great improvements on the recognition rate over the conventional method, showing about 77% in contrast to only 23%.