• Speech Sciences
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• v.5 no.1
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• pp.63-80
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• 1999

In this paper, an adaptive method of dividing a speech signal into an initial, a medial and a final sound of the form of utterance utilized by evaluating extreme limits of short term energy and autocorrelation functions. By applying this method into speech signal composed of a consonant, a vowel and a consonant, it was divided into an initial, a medial and a final sound and its feature analysis of sample by LPC were carried out. As a result of spectrum analysis in each period, it was observed that there existed spectrum features of a consonant and a vowel in the initial and medial periods respectively and features of both in a final sound. Also, when all kinds of words were adaptively divided into 3 periods by using the proposed method, it was found that the initial sounds of the same consonant and the medial sounds of the same vowels have the same spectrum characteristics respectively, but the final sound showed different spectrum characteristics even if it had the same consonant as the initial sound.

• Journal of Korea Multimedia Society
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• v.9 no.7
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• pp.801-807
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• 2006

This study analyzed the timbral characteristics of Pliri by basis step for the sound synthesis for Piri, Korean traditional musical Instrument. By analyzing this material, we can find out three characteristics about the study of the spectrum analysis for the sound synthesis of Piri. First, compared the timbral characteristics of Piri with Oboe through the spectrum analysis, Second, analyzed the timbral characteristics by the sound occurrence process through the time zone analysis of the attack part of the sound started. Finally, analyzed the special characteristics of the vibrato that is important role of musical instrument performance. As a result, the timbral characteristics of Piri is that the volume of the high harmonics was appeared to be high unlike the general classical instrument and the noise quantity rapidly decreased in the sound attack part but the volume value of harmonics increased. And also vibrato that is performance technique is changed pitch and amplitude at the same time by contrast with the general classical instrument. Thus, the timbral characteristic of Piri by the harmonics and the timbre change by the attack part which is sound occurrence process and the change of the pitch and amplitude in the vibrato is characteristic that represented unique quality of Piri. We expect that this achievement can be applied to sound synthesis.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.287-293
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• 2020

More and more people are paying attention to the psychological pleasure and relaxation that sound hearing brings. In most cases, humans seem to have a special preference for natural sounds. Natural sounds are mainly white noise and pink noise such as wind, rain, waves, waterfall sounds, etc. All of these are often considered to be beneficial to human health, but in reality the same category of natural sounds is no different. It will be very different due to space, time and other factors. Each sound can be unique, so people's hearing experience is also different. This paper quantitatively analyzes the spectrum and brain waves to analyze the feeling of hearing the natural Broken Falls sound. In particular, we aim to objectively analyze the objective feeling of Broken Falls sound falling on the human auditory system through sound spectrum and brain waves.

• Journal of Biomedical Engineering Research
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• v.10 no.2
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• pp.151-156
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• 1989

Lung sound analyer which can provide an objective diagnosis of patients with pulmonary and bronchial disorders is designed. For the purpose of power spectrum analysis, adaptive digital filtering technique and TM - S320C25 DSP chip is used. As a results, adaptive lattice Wiener filter could eliminate heart sounds with a few of 10th order and on the distribution of power spectrum each patterns has shown in normal vescicular breathy from 100 Hz to 200 Hz, in crackle sound from 100 Hz to 400 Hz, in wheeze sound from 150 Hz to 600 Hz.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.752-757
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• 1994

Very often, one would like to have visual image of mechanical or acoustical events such as musical sound and transient vibrations. Conventional methods to visualize the signal, such as power spectrum, do not normally allow to cultivate the signal of interests due to their inherent limitation on transient signals. Other than the conventional method, one could use an instantaneous frequency which can reveal the variation of frequency in terms of time. Nevertheless it is quite sensitive to noise and can not resolve the frequency components of signals; normally produces additional components other than those of the signals. In this paper, we introduce the Wigner-Ville spectrum to see the transient characteristics of signal, especially musical sound and transient mechanical vibration signatures. For musical sound, several popular western classic music have been selected for the analysis. For the transient mechanical signature, the signals obtained from the car door experiment and the beam experiment are interpreted in terms of Wigner-Ville spectrum. Results demonstrate the visual expressions of transient signals; musical sound and vibrations.

• The Journal of the Acoustical Society of Korea
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• v.25 no.3E
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• pp.89-94
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• 2006

For audio indexing and targeted search of specific audio or corresponding visual contents, the MPEG-7 standard has adopted a sound classification framework, in which dimension-reduced Audio Spectrum Projection (ASP) features are used to train continuous hidden Markov models (HMMs) for classification of various sounds. The MPEG-7 employs Principal Component Analysis (PCA) or Independent Component Analysis (ICA) for the dimensional reduction. Other well-established techniques include Non-negative Matrix Factorization (NMF), Linear Discriminant Analysis (LDA) and Discrete Cosine Transformation (DCT). In this paper we compare the performance of different dimensional reduction methods with Gaussian mixture models (GMMs) and HMMs in the classifying video sound clips.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1113-1116
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• 2003

In this paper, it is suggested that the technology sound measurement which is to search the inferiority of the plate during the pressing. We evaluate whether there is a inferiority by analysing and comparing the satisfactory and inferior plate with the method of a spectrum analysis by measuring the sound which is emitted during pressing. We designed the analysis algorithm to detect inferior plate throughout comparison of measured sound data using FFT, DFT and DASYLab S/W. In addition to these, we suggest the way to compare both inferior and satisfactory signal statistically.

• International Journal of Advanced Culture Technology
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• v.9 no.2
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• pp.123-129
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• 2021

When shaving, it is easy to suffer shaving burns, that is, facial burn irritation during shaving. The reason is that the razor blade irritates the skin. The current solution is to make the razor sharper and use a razor with a blade heating function. Although these ways can increase the comfort of shaving, they will also greatly increase shaving costs. This paper proposes using a hairdryer to massage the skin before shaving to reduce skin irritation during shaving. This is a simple, practical and low-cost method. The hair dryer's heat, sound, and wind energy have a massage effect, and they can make shaving easier and more comfortable. For analyzing shaving effect, two evaluation methods are used, which are sound spectrum analysis and mos. The sound spectrum analysis is used to analyze the working status of the razor objectively. The MOS test can reflect the subjective feelings of the subject on the shaving's comfort. The results show that the hairdryer thermal vibration massage can make the beard easier to cut, thereby reducing the irritation of the razor to the skin and improving shaving comfort.

• The KIPS Transactions:PartB
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• v.17B no.1
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• pp.69-78
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• 2010

Spectral modeling synthesis (SMS) has been used as a powerful tool for musical sound modeling. This technique considers a sound as a combination of a deterministic plus a stochastic component. The deterministic component is represented by the series of sinusoids that are described by amplitude, frequency, and phase functions and the stochastic component is represented by a series of magnitude spectrum envelopes that functions as a time varying filter excited by white noise. These representations make it possible for a synthesized sound to attain all the perceptual characteristics of the original sound. However, sometimes considerable phase variations occur in the deterministic component by using the conventional SMS for the complex sound such as whale sounds when the partial frequencies in successive frames differ. This is because it utilizes the calculated phase to synthesize deterministic component of the sound. As a result, it does not provide a good spectrum matching between original and synthesized spectrum in higher frequency region. To overcome this problem, we propose a modified SMS that provides good spectrum matching of original and synthesized sound by calculating complex residual spectrum in frequency domain and utilizing original phase information to synthesize the deterministic component of the sound. Analysis and simulation results for synthesizing whale sounds suggest that the proposed method is comparable to the conventional SMS in both time and frequency domain. However, the proposed method outperforms the SMS in better spectrum matching.

• ETRI Journal
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• v.37 no.4
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• pp.824-832
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• 2015

Heart sounds are the main obstacle in lung sound analysis. To tackle this obstacle, we propose a diagnosis algorithm that uses singular spectrum analysis (SSA) and frequency features of heart and lung sounds. In particular, we introduce a frequency coefficient that shows the frequency difference between heart and lung sounds. The proposed algorithm is applied to a synthetic mixture of heart and lung sounds. The results show that heart sounds can be extracted successfully and localizations for the first and second heart sounds are remarkably performed. An error analysis of the localization results shows that the proposed algorithm has fewer errors compared to the SSA method, which is one of the most powerful methods in the localization of heart sounds. The presented algorithm is also applied in the cases of recorded respiratory sounds from the chest walls of five healthy subjects. The efficiency of the algorithm in extracting heart sounds from the recorded breathing sounds is verified with power spectral density evaluations and listening. Most studies have used only normal respiratory sounds, whereas we additionally use abnormal breathing sounds to validate the strength of our achievements.