Noise reduction system using modified DFT pair

Author

NAKANISHI, Isao ; Itoh, Yoshio ; Fukui, Yutaka ; Fujii, Kensaku

Author_Institution

Tottori Univ., Japan

Volume

2

fYear

2001

fDate

6-9 May 2001

Firstpage

9

Abstract

This paper presents a noise reduction system based on the modified DFT (MDFT) pair. The modified DFT decomposes noisy speech into sinusoidal signals which have the amplitude and phase spectra as the MDFT output. From each MDFT output, speech and noise spectra are extracted through level detectors. These detectors basically consist of the IIR filters with large time constants. By using the detected spectra, noise reduction is achieved in tile MDFT output and noise reduced speech is reconstructed by the modified IDFT (MIDFT) by only adding all MDFT outputs. The proposed system requires no preliminary estimation of noise spectrum since speech and noise spectra are extracted every sample time. The realization and effectiveness of the proposed system are confirmed through computer simulations

Keywords

IIR filters; digital simulation; discrete Fourier transforms; interference suppression; spectral analysis; speech enhancement; IIR filters; MDFT output; computer simulation; level detectors; modified DFT pair; modified IDFT; noise reduction; noise spectra; noise spectrum; noisy speech; reconstructed; sinusoidal signals; speech and noise spectra; Delay; Detectors; Integrated circuit noise; Noise generators; Noise level; Noise reduction; Oral communication; Phase noise; Speech enhancement; Working environment noise;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2001. ISCAS 2001. The 2001 IEEE International Symposium on

Conference_Location

Sydney, NSW

Print_ISBN

0-7803-6685-9

Type

conf

DOI

10.1109/ISCAS.2001.920993

Filename

920993