ABSTRACT
Speech signal analysis is one of the important areas of
research in multimedia applications. Discrete Wavelet technique is
effectively reduces the unwanted higher or lower order frequency
components in a speech signal. Wavelet-based algorithm for audio
de-noising is worked out. We focused on audio signals corrupted with
white Gaussian noise which is especially hard to remove because it is
located in all frequencies. We use Discrete Wavelet transform (DWT) to
transform noisy audio signal in wavelet domain. It is assumed that high
amplitude DWT coefficients represent signal, and low amplitude
coefficients represent noise. Using thresholding of coefficients and
transforming them back to time domain it is possible to get audio signal
with less noise. Our work has been modified by changing universal
thresholding of coefficients which results with better audio signal. In
this various parameters such as SNR, Elapsed Time, and Threshold value
is analyzed on various types of wavelet techniques alike Coiflet,
Daubechies, Symlet etc. In all these, best Daubechies as compared to SNR
is more for Denoising and Elapsed Time is less than others for Soft
thresholding. In using hard thresholding Symlet wavelet also works
better than coiflet and Daubechies is best for all. Efficiency is 98.3
for de-noising audio signals which also gives us better results than
various filters.
Audio noise reduction system is the system that is used to remove the noise from the audio signals. Audio noise reduction systems can be divided into two basic approaches. The first approach is the complementary type which involves compressing the audio signal in some well-defined manner before it is recorded (primarily on tape). The second approach is the single-ended or non-complementary type which utilizes techniques to reduce the noise level already present in the source material—in essence a playback only noise reduction system. This approach is used by the LM1894 integrated circuit, designed specifically for the reduction of audible noise in virtually any audio source. Noise reduction is the process of removing noise from a signal.
Audio noise reduction system is the system that is used to remove the noise from the audio signals. Audio noise reduction systems can be divided into two basic approaches. The first approach is the complementary type which involves compressing the audio signal in some well-defined manner before it is recorded (primarily on tape). The second approach is the single-ended or non-complementary type which utilizes techniques to reduce the noise level already present in the source material—in essence a playback only noise reduction system. This approach is used by the LM1894 integrated circuit, designed specifically for the reduction of audible noise in virtually any audio source. Noise reduction is the process of removing noise from a signal.
PROJECT OUTPUT
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