• Title/Summary/Keyword: Sound Spectrum Analysis

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A Study on a Method of U/V Decision by Using The LSP Parameter in The Speech Signal (LSP 파라미터를 이용한 음성신호의 성분분리에 관한 연구)

  • 이희원;나덕수;정찬중;배명진
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.1107-1110
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    • 1999
  • In speech signal processing, the accurate decision of the voiced/unvoiced sound is important for robust word recognition and analysis and a high coding efficiency. In this paper, we propose the mehod of the voiced/unvoiced decision using the LSP parameter which represents the spectrum characteristics of the speech signal. The voiced sound has many more LSP parameters in low frequency region. To the contrary, the unvoiced sound has many more LSP parameters in high frequency region. That is, the LSP parameter distribution of the voiced sound is different to that of the unvoiced sound. Also, the voiced sound has the minimun value of sequantial intervals of the LSP parameters in low frequency region. The unvoiced sound has it in high frequency region. we decide the voiced/unvoiced sound by using this charateristics. We used the proposed method to some continuous speech and then achieved good performance.

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Analysis of Low-frequency Reverberation Inshallow Water (천해에서의 저주파 잔향음 분석)

  • 박길선;나정열;최지웅;오선택;박정수
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.4
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    • pp.94-100
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    • 2001
  • In October 1997, low-frequency reverberation was measured at an experimental site off the west coast of the Jeju island using the explosive charge, Signals Underwater Sound (SUS). Received signals were separated into the noise, the reflection, and the scattering region, and then were analyzed for the spectral and statistical characteristics of each region. In the analysis of the spectrum we verified that each region had a unique frequency band and statistical characteristics as well. The results of this analysis showed that the real and imaginary portions were shown to be both normal distributions in each frequency bin. The reverberation envelope had a Rayleigh distribution and the phase had a uniform distribution.

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Physical Analysis of the Prosthetic Valve Sound (기계판막치환후의 판막음에 대한 연구)

  • 조범구
    • Journal of Chest Surgery
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    • v.22 no.4
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    • pp.589-593
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    • 1989
  • The frequency spectrum of the metallic closing sound and its loudness were measured by non invasive techniques in 66 patients. They had examined a total of 7 Carbomedics valve, 10 Duromedics valve, 11 St. Jude heart valve in mitral position and 8 Carbomedics, 10 Duromedics, 20 St. Jude heart valve prostheses functioning normally in aortic position. Statistical comparison of the loudness from sound produced by the three valves in each position, the following; The Carbomedics valve has the lowest average loudness, followed by the St. Jude medical valve, and finally the Edward Duromedics valve. And we analysis the changing factor of the loudness of valve sound, only the velocity of the flow through the valve influenced to the valve sound.

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Development of Parameter Extraction Algorithm and Software Simulator For a Digital Music FM Synthesis (FM 방식의 디지털 악기음 합성을 위한 소프트웨어 시뮬레이터 및 파라미터 추출 알고리즘 개발)

  • Joon Yul Joo
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.3
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    • pp.24-38
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    • 1994
  • In this paper we develop the software simulator written in a C language for a frequency modulation synthesis and the approximate range of parameters, for a musically satisfactory timbre, obtained by using the software simulator will be applied to develop an algorithm for parameter extraction. For a frequency modulation synthesis, we also develop an algorithm for parameter extraction through waveform analysis in the time domain as well as spectrum analysis using a FFT in the frequency domain. To verify the validity of the developed algorithm as well as software simulator experimentally, we extract parameters for the several music instruments using the suggested algorithm and analyze the synthesized sound by applying the parameters to the software simulator. The evaluation of the synthesized sound is first done by listening the sound directly as a subjective testing. Secondly, to evaluate the synthesized sound objectively with an engineering sense, we compare the synthesized sound with an original one in a time domain and a frequency domain.

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Analysis of Sound Transmitting System using Power line Communication Technique (전력선을 이용한 음향전달 시스템의 구성 및 특성 분석)

  • Kim, Ho-Soo;Lee, Myung-Sub;Koo, Kyung-Wan;Han, Sang-Ok
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.3
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    • pp.128-134
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    • 2004
  • This paper presents a result of sound transmitting system with power line communication technique. Sound transmitting system is a transmitter which transmits modulated audio signal to power to power line and receiver which is capable of detecting it with earphone or speaker. It has been evaluated with the frequency characteristics and spectrum analysis. And, from the result of evaluation on the developed system, we confirmed the superior sound transmitting characteristics, and the possibility of application on a language laboratory.

Frequency Spectrum Analysis of Corona Discharge Source Measured by Ultrasound Detector (초음파 감지기로 측정한 코로나 방전 소스의 주파수 스펙트럼 분석)

  • Cho, Hyun-Seob
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.1
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    • pp.78-82
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    • 2019
  • This paper addressed the spectrum of ultrasonic waves produced by arc and/or coronal discharge inside the switchboard. Portable ultrasound sensors are useful for detecting discharge phenomena, such as coronal means in electrical systems. However, a typical handheld ultrasound detector has a disadvantage of determining the type of problem by listening to the sound characteristics and predicting the results, as a result of the determination of whether a discharge is present. Therefore, a new method of analysis is required to distinguish ultrasonic characteristics. In this paper, we published an ultrasound analysis case study to visualize the sound of ultrasonic waves measured with ultrasonic sensors. From the results of the experiment, it was possible to detect coronal discharge and serial arc discharge without interference by the ultrasonic detection system.

SOUND AND VIBRATION STUDY OF ROTARY COMPRESSOR (로터리 콤프레셔의 소음 진동 연구)

  • 박종찬;왕세명
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.973-978
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    • 2001
  • Noise reduction has become a major issue of the manufacturing industry. This paper describes the reduction of noise and vibration of rotary compressors. Empirical design for the present strap of the accumulator has been considered to be sufficient for the constraint of the accumulator resonance modes without thorough study. Recently, however, some researchers found out that the accumulator contributes considerably to the sound propagation. In this paper, the contribution of accumulator to the noise propagation is investigated through sound measuring experiments by checking the directivity of the noise. And, experimental modal analysis results show that frequencies of some resonance modes of the accumulator coincide with the highest peaks on sound spectrum. To demonstrate the reason for those resonance modes, a finite element analysis is conducted. Normal mode analysis of the finite element model of the rotary compressor shows the mechanism of the accumulator resonance modes.

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The Study on noise Analysis of Bush on Suspension System (현가계 부쉬 이상소음 분식에 관한 연구)

  • Bae, Chul-Yong;Lee, Dong-Won;Kim, Chan-Jung;Lee, Bong-Hyun;Na, Byung-Chul
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.69-74
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    • 2006
  • It is known that the various noise sources which are engine, transmission, tire, intake system, etc exist at vehicle driving status. Specially noises which cannot be expected by a driver induce unpleasantness to all passengers. These noises are difficult to distinguish noise sources or specifications because of too many vehicle parts. Therefore in this paper, study on abnormal noise of bush on suspension system is performed by the measurement and analysis of the noises of bushings that are generated artificially. The measured noises are analyzed by two points-view of spectrum and sound quality. Finally, it is shown that the noise sources of bushings on the suspension system which are the pillow ball joint bush of a control arm and the rubber bush of a lower arm could be distinguished by the spectrum distribution and a index value based on tonality.

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A Study on Noise Source Identification for Loading Mechanism and Rattle noise about A/V System (차량용 A/V 시스템의 구동부 소음원과 래틀 소음원에 관한 연구)

  • 홍종호;강연준;이상호;이완우;이기석
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.189-195
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    • 2003
  • This paper represents an identification procedure for leading mechanism of a car A/V system which is composed of a DC motor and a set of plastic gears. In addition, we studied dominant noise source of rattle noise generated by external forced vibration as a car drives. we made a dynamometer to produce stationary operation on loading mechanism of A/V system because noise generated by actual loading mechanism is non-stationary signal. operating the dynamometer setup at various motor speeds, sound pressure spectra are measured and the results are analyzed. its dominant noise source is also identified by using a sound Intensity technique. we made use of multi-dimensional spectral analysis to rind a dominant rattle noise. this method is so useful to eliminate coherence between vibration sources and helps us obtain coherent output spectrum of individual vibration source which make a rattle noise.

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A study imitating human auditory system for tracking the position of sound source (인간의 청각 시스템을 응용한 음원위치 추정에 관한 연구)

  • Bae, Jeen-Man;Cho, Sun-Ho;Park, Chong-Kuk
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.878-881
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    • 2003
  • To acquire an appointed speaker's clear voice signal from inspect-camera, picture-conference or hands free microphone eliminating interference noises needs to be preceded speaker's position automatically. Presumption of sound source position's basic algorithm is about measuring TDOA(Time Difference Of Arrival) from reaching same signals between two microphones. This main project uses ADF(Adaptive Delay Filter) [4] and CPS(Cross Power Spectrum) [5] which are one of the most important analysis of TDOA. From these analysis this project proposes presumption of real time sound source position and improved model NI-ADF which makes possible to presume both directions of sound source position. NI-ADF noticed that if auditory sense of humankind reaches above to some specified level in specified frequency, it will accept sound through activated nerve. NI-ADF also proposes practicable algorithm, the presumption of real time sound source position including both directions, that when microphone loads to some specified system, it will use sounds level difference from external system related to sounds of diffraction phenomenon. In accordance with the project, when existing both direction adaptation filter's algorithm measures sound source, it increases more than twice number by measuring one way. Preserving this weak point, this project proposes improved algorithm to presume real time in both directions.

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