Enhancement of speech in noisy conditions project presentation paul coffey
Download
1 / 15

Enhancement of Speech in Noisy Conditions Project Presentation Paul Coffey - PowerPoint PPT Presentation


  • 91 Views
  • Uploaded on

Enhancement of Speech in Noisy Conditions Project Presentation Paul Coffey. Contents. Project Overview System Development Testing Conclusion. Project Overview. This project is about The “Enhancement of Speech in Noisy Conditions” Speech Enhancement is used in communications everywhere

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Enhancement of Speech in Noisy Conditions Project Presentation Paul Coffey' - clarke


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Enhancement of speech in noisy conditions project presentation paul coffey

Enhancement of Speech in Noisy Conditions

Project Presentation

Paul Coffey


Contents
Contents

Project Overview

System Development

Testing

Conclusion

Project Presentation


Project overview
Project Overview

  • This project is about The “Enhancement of Speech in Noisy Conditions”

  • Speech Enhancement is used in communications everywhere

    • From Mobile Phones to Speech Recognition Systems

Project Presentation


Project overview1

Noisy Signal

Analysis Window

Fourier Transform

Spectral Modification

Inverse Fourier Transform

Synthesis Window

Overlap Add

Enhanced Signal

Project Overview

  • To Investigate Spectral Subtraction

    • A method to improve the quality of a signal that has been effected by noise

    • This is done by taking noise from degraded signal

Project Presentation


Project overview2

Noisy Signal

Speech and noise power spectrum estimation

PXX(f) PNN(f)

Wiener Filtering

Enhanced Signal

Project Overview

  • Implement Wiener Filter Method

    • Is derived and Works on same basis as Spectral Subtraction

Project Presentation


System development
System Development

  • To begin development, a simple task such as doubling the magnitude was implemented

  • Also getting the system to analyse and synthesise the whole signal

  • Hamming Windows and Overlap Add were also introduced to the system

Project Presentation


System development1
System Development

  • Finally a basic Spectral Subtraction implementation of the filter was then achieved

  • Result from running the filter is shown

  • MagY = MagX – MagNN;

Project Presentation


System development2
System Development

  • The other filter that was developed was the Wiener Filter

  • This was approached in the same way as the previous filter

  • Since this method is similar to the way it is derived as Spectral Subtraction, this greatly helped with speeding up development

Project Presentation


System development3
System Development

  • Basic Wiener Filter Implementation

  • Result of the signal being filtered shown

  • This is implemented using the code below:

    W = MagX./(MagX+MagNN);

    MagY = MagX .* W;

Project Presentation


System development4
System Development

  • Noise Detection and SNR were also needed to be developed

  • These were required for the filters to operate properly

  • Finding the energy levels of the signal was used to implement the noise detection method

  • The code to do so is: E = sum (x.^2);

  • The SNR is then was developed using the equation

Project Presentation


Testing
Testing

  • Throughout the project tests were being carried out to see how the filters were working

  • Spectral

    Subtraction

    here with SNR

    of 10db

Project Presentation


Testing1
Testing

  • Here is the Wiener Filter Implementation with SNR at 10db

  • It is the same speech signal as used in the Spectral Subtraction implementation

  • Can see Wiener doesn’t cut out speech like the Spectral did

Project Presentation


Testing2
Testing

  • A blind test was carried out involving ten student in the Electronics Department

  • Consisted of number of different samples at different levels of SNR

  • Results from this test showed at low levels of SNR the two filters are very close

  • Then at higher levels of SNR the Wiener Filter is preferred

Project Presentation


Conclusion
Conclusion

  • Speech Enhancement techniques are a very important part of Communication Systems

  • The two techniques, Spectral Subtraction and the Wiener Filter were implemented

  • From the testing the Wiener Filter was the preferred choice over the Spectral Subtraction

Project Presentation


Questions
Questions?

Project Presentation


ad