A NEW APPROACH OF SPEECH COMPRESSION BY USING DWT & DCT
RATISH KUMAR
1
& HEMANT AMHIA
2
1
Department of Electrical Engineering, Jabalpur Engineering College, Jabalpur, Madhya Pradesh, India
2
Professor, Jabalpur Engineering College, Jabalpur, Madhya Pradesh, India
ABSTRACT
With the growth of multimedia technology over past decades, the demand for digital information increase
dramatically. The enormous demand poses difficulties in handling speech compression. Speech compression is a mature
technology with many applications. To overcome this problem is to compress the information by removing redundancies
present in it. Lossy compression scheme that is often used to compress information such as speech signals.
This paper presents a method of transformation for the compression of speech signal.
In this paper a new lossy algorithm to compress speech signal using discrete wavelet transform (DWT) and then
again compressed by discrete cosine transform (DCT) then decompressed it by discrete cosine transform afterward
decompressed by discrete wavelet transform to retrieve the original signal in compressed form. To measure the
performance of speech signal on the basis of signal to noise ratio (SNR) and mean square error (MSE) by using different
filter of wavelet families.
KEYWORDS: DWT, DCT, Speech Compression & Decompression, PSNR, MSE
INTRODUCTION
Speech is a very basic way for humans to convey information to one another. With a bandwidth of
400Hz to 4kHz, speech can carry information with different colour of emotion of a human voice. Now a day’s people are
able to hear someone’s voice from anywhere in the world-as if the person would be in the same location and they are
talking in face to face. Speech can be defined such as the response of the vocal tract to one or more excitation signals.
Compression of signals is based on removing the redundancy between neighbouring samples and/or between the
adjacent cycles. In data compression, it is desired to represent data by as small as possible number of coefficient within an
acceptable loss of visual quality. Compression techniques can be classified into one of two main categories: lossy and
lossless.
Compression methods can be classified into three functional categories:
Direct Methods: The samples of the signal are directly handled to provide compression.
In transformation method the signal is transformed into frequency domain. In transform method we use Discrete
wavelet transform and Discrete cosine transform. Transformation techniques don’t compress the signal, they provide
information they provide information about the signal and using various encoding technique compression of signal.
BEST: International Journal of Management, Information
Technology and Engineering (BEST: IJMITE)
ISSN 2348-0513
Vol. 2, Issue 8, Aug 2014, 9-14
© BEST Journals