A Study on the Audio Compensation System

Byung-Chul† Jeoung; Chung-Sang* Won

doi:10.7776/ASK.2013.32.6.509

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2013 Vol.32, Issue 6 Preview Page Next Page

A Study on the Audio Compensation System 음향 보상 시스템에 관한 연구

30 November 2013. pp. 509-517

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Abstract

In this paper, we researched a method that makes a good acoustic-speech system using a digital signal processing technique with dynamic microphone as a transducer. Good acoustic-speech system should deliver the original sound input to electric signal without distortion. By measuring the frequency response of the microphone, adjustment factors are obtained by comparing measured data and standard frequency response of microphone for each frequency band. The final sound levels are obtained using the developed adjustment factors of frequency responses from the microphone and speaker to match the original sound levels using the digital signal processing technique. Then, we minimize the changes in the frequency response and level due to the variation of the distance from source to microphone, where the frequency responses were measured according to the distance changes.

Keywords

Microphone

Speaker

Frequency response

Nonlinear distortion

FFT

iFFT

Audio compensation

본 연구에서는 음성전기변환기로서 다이나믹 마이크로폰과 디지털 신호처리기를 사용하고 성능분석을 통해 좋은 음성신호를 출력하는 방법을 다루었다. 음성음향시스템의 성능이라 함은 음성신호를 왜곡하지 않고 얼마나 원음특성을 충실하게 증폭하여 확성하는가를 뜻한다. 마이크로폰의 주파수 응답특성을 측정한 후, 신호처리방법으로 표준마이크로폰 주파수 응답특성과 비교하여 주파수대역 별 보정치를 구하였다. 본 논문에 사용된 마이크로폰과 스피커는 일반적으로 사용되는 제품으로, 주파수응답특성을 구하고 기준치와 비교하여 필요한 보정치를 구하였다. 이와 같이 구한 마이크로폰과 스피커의 보정치는 디지털신호처리방법으로 처리하여 원신호음에 가깝게 보상하였다. 그리고 음성음원과 수음마이크 사이의 거리변화에 의한 음향특성변화보상에 관한 측정 결과도 비교적 좋은 결과를 얻었다.

키워드

마이크로폰

스피커

주파수응답특성

비선형성 왜곡

FFT

iFFT

음향보상

References

1.M. Schetzen, The Volterra and Wiener Theories of nonlinear Systems (John Wiley, New York, 1980), pp. 125-136.

2.V. J. Mathews, “Adaptive polynomial Filters,” IEEE Signal Process. mag. 8, 110-26 (1991).

3.V. J. Mathews and G. L. Sicuranza, Polynomial Signal Processing (John Wiley, New York, 2000), pp. 211-219.

4.W. Klippel, “The mirror Filter-A new basis for reducing nonlinear distortion and equalizing response in woofer systems,” J. Audio Eng. Soc. 40, 675-691 (1992).

5.H. Schurer. C. Slemp and O. E. Herrmann, “Theoretical and experimental compariron of three methods for compen-sation of electrodynamic transducer nonlinearity,” J. Audio Eng. Soc. 46, 723-740 (1980).

6.B. C. Jeoung and Y.-S. Choe, “A study on the compensating system for the acoustic characteristics caused by the variation of distance from sound source to microphone” (in Korean), J. Acoust. Soc. Kr. 31, 197-204 (2012).

7.S. S. Jarng, “An experimental study on the fitting of 64 channel digital hearing aid by in-situ method” (in Korean), J. Acoust. Soc. Kr. 31, 273-275 (2012).

8.I. W. Cha, Acoustical Engineering (in Korean, Hanshin moonhwa co., 1976), pp. 13-23.

Information

Publisher :The Acoustical Society of Korea
Publisher(Ko) :한국음향학회
Journal Title :The Journal of the Acoustical Society of Korea
Journal Title(Ko) :한국음향학회지
Volume : 32
No :6
Pages :509-517
Received Date : 2013-08-08
Accepted Date : 2013-09-26
DOI :https://doi.org/10.7776/ASK.2013.32.6.509

The Journal of the Acoustical Society of KoreaISSN:1225-4428(Print) 2287-3775(Online)한국음향학회

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