Seong-Geon Bae

On a New Enhancement of Speech Signal Using Non-uniform Sampling and Post Filter

To enhance speech signal by reducing the redundancy within samples that resulted from uniform sampling method like PCM, non-uniform sampling or non-redundant-sample coding methods can be considered. However, it is well known that when conventional non-uniform sampling methods are applied directly to speech signal, the required amount of data in the computation is comparable to or more than that of uniform sampling method. To overcome this problem, a new non-uniform sampling method is proposed, in which non-uniform sampling is applied to the speech signal after using the low pass filter and the remain signals are compensated by the rectified signals with various harmonics frequencies.

A Study on Enhancement of Speech Signal Using Separated Bandwidth and Non-uniform Sampling

There are various methods to improve signal quality under the environments of noised signal in the speech signal processing. In the case of the majority of signal restoration, it will be concentrated in signal quality for deterioration of low frequency as they are also converged into voiced signal from the characteristic of speech quality deterioration. Therefore, in the case of deterioration of voiced signal section, great efforts have been contributed for quality improvement and restoration. Other case of clipped signal section is for signal reconstruction. In this paper, the method to improve voiced and clipped signal will be proposed. Voiced signal in noisy and clipped section is created by utilizing the fact that differentiation and clipped signal are supposed to give small influence for the evaluation of recognition level. For the signal which is obtained by stressing amplitude at voiced signal section where most of them are distributed, the method of emphasizing synthesis with original signal was used. In this paper we propose the method which enhances the voiced signals by dividing the clipped signal and the low frequency signal. We differentiate the signals and use the fact that signals have little effect on perception to make voiced part, and isolated the high frequency part through low pass filter.

A study on auditory sensitivity and behavioral cognition changes before and after drinking in psychological acoustics

In general, an auditory sensitivity after drinking is becoming insensitive and a perception of behavior becomes very poor. This can be explained by the characteristics of body changes due to alcohol absorption, and this study analyzed and studied these characteristics. This study provides the necessary bases for psychoacoustics and brain cognitive science by obtaining a measured data through cognitive testing of the characteristics of body changes before and after drinking. We analyzed the post-drinking changes in brain waves and performed psychoacoustic analysis of these characteristics.

A study on a sound fire extinguisher using special sound lens

Sound fire extinguisher is developed based on principle of quenching fire by blocking inflow of oxygen with contacting vibration energy from low frequency sound under 100 Hz to fire and then, lowering its temperature. The first sound fire extinguisher made by a Federal Defence researcher was very huge and based on theory of initial principles, making it hard to be commercialized. Although next sound fire extinguisher developed by students of George Mason University was smaller than before, it was also at the basic stage with early theory. What is more, disturbance from the too long cable and inconvenience of having to carry all the tools were not effective to be commercialized. By improving these drawbacks, Sori Sound Engineering Research Institute (SSERI) of Soongsil University has developed new concept sound fire distinguisher. It concentrates sound through special sound lens and increases energy 10 times more to put out the fire. This study researches about reducing weight of sound fire extinguisher ba...

A study on the summer forest sound acoustic characteristics using psychoacoustics parameters in South Korea

In this paper, summer forest sound acoustic characteristics has been analyzed through psychoacoustics Parameters. Forest sound is closely related to Psychological factors of the human which are analyzed variously. Forest sound is applied to the improvement of depression and anxiety of psychology characteristics. Thus, we study efficient method to apply acoustic properties of forest sound using psychoacoustics parameters.

A study on the effects of depression using the weighting white noise

In general, depression is a disease that appears negative emotions and changes negative emotions in brain function. Fifteen percentage of the population suffers from anxiety disorders and depression at least once during a lifetime. Delta waves are often found to increase in depressed patients than in the general population, which cause negative emotions. The alpha waves increases in the left frontal lobe, and the beta waves increases in the right frontal lobe. Depending on the brain waves, patients with depression have such characteristics. In this study, we used a white noise for the symptoms of depression. Analysis of depression in a white noise is advantageous than the using EEG features. White noise weight has an effect on depression.

A New Judgment of Intoxication Based on Changes in Low Frequency Characteristics of Speech Signal

This research examines parameters of drinking judgment by comparing sound characteristics before and after drinking using voice analysis. Until now, characteristics of drinkers are studied from perspectives of pitch, formant, and changes in size of sound, however, as these factors are very sensitive to environmental changes to be used as a measurer for judging drinking, it is important to find more accurate parameters. Especially, changes in high frequency and low frequency have to be separated to identify sound characteristics and thus, if environment changes this many lead to calculation of inaccurate parameters. Therefore, this research studies about characteristics before and after drinking by using addition signal, which enables application to various environment along with more accurate analysis. Keyword-Judgement of intoxication, High frequency signal, Formant, Pitch

A Study on Individual Frequency Bandwidth using Addition Signal in Noise Signal

This paper proposes different ways to study individualized bandwidth. This bandwidth is used in noise signal for recognition and analysis in various ways but previous methods only apply weighted dB(A) and dB(C) to sound pressure level or one in low frequency scope. Also, there are A weight sound level ( ), NC curve (Noise Criteria Curves), and NR curve (Noise Rating Curves). This research tries to find out about individualized bandwidth by using frequency bandwidth and applying this to different fields such as recognition, analysis, and reduction. Keyword-Individual frequency, Bandwidth, Formant

Sound characteristic analysis of Multi-layer sound- absorbing materials using impedance tube

With the development of the field of transportation, vehicles have come to be driven fast. As a result, due to their high speed, railways are the cause of increased noise inside the railway vehicle. Methods for reducing noise present themselves in various ways. However, it is difficult for a method to be effective without a costly and difficult implementation of technology. In general, to improve the characteristics of vehicle interior noise conditions, which can increases the effect of sound absorbing or insulation materials, it is necessary that any sound absorbing material be located between the outer and inner walls of the vehicle. In this paper, we perform an experiment on the acoustic characteristics of a composite multilayer type sound-absorbing material that can be used to reduce the interior noise of a vehicle. In our tests, we used an impedance tube, which can scan a plane wave with a speaker for the test-material. The tube is fabricated in a circular symmetrical shape. This overall method can b...

A study of Foley Sound based on analysis and compare of the bird’s chirping

This research verifies use value of Foley sound of bird‘s chirping used in Radio drama as sound contents by comparing and analyzing it with Actual sound. Radio drama utilizes sound of bird‘s chirping to show season, time, and place in various ways. Currently, this sound is used as sound effect in media by recording Actual sound of bird‘s chirping on site with portable recorder. Before when no portable recording device existed, they had to make Foley sound. To have comparative analysis of Actual and Foley sound of bird‘s chirping, production method of Foley sound tools and their usage were studied. To conclude, as Foley sound tools used for sound of bird‘s chirping are very unique and interesting there is a high possibility of developing them into Sound contents for Performance and Exhibition.