Voice recognition security system in matlab

Replies

• 

  Kaustubh Katdare

  Thread moved to electrical / electronics engineering section with a better title 😀
• 

  Predictor

  pulkit.143

  man m makin a voice recognition security system in matlab...can u guide me how to go about it especially the feature extraction and pattern matching part...

  How far have you gotten? Have you extracted features already? Have you built any pattern matchers? Where are you stuck?
  
  
  -Will Dwinnell
  Data Mining in MATLAB
• 

  pulkit.143

  i hav imported the sound file in matlab ...now i want to plot its fft...den i want to plot fft s of the already stored samples n compare both....actly m new in matlab so m facing al dese prblms...i need urgent help wid the source code or may b a part of it...thanx..
• 

  Predictor

  pulkit.143

  i hav imported the sound file in matlab ...now i want to plot its fft...den i want to plot fft s of the already stored samples n compare both....actly m new in matlab so m facing al dese prblms...i need urgent help wid the source code or may b a part of it...

  Please spell out your words more in the future? You are dropping many letters and it is difficult to understand.
  
  You can use the fft function to calculate the discrete Fourier transform, but be aware that the result is stored as complex numbers (real and imaginary components) to store the Fourier phase and magnitude information. See help fft for more information. You can plot multiple traces on the same graph, as shown by help plot: plot(X,Y,'y-',X,Y,'go')
  
  
  -Will Dwinnell
  Data Mining in MATLAB
• 

  pulkit.143

  hey predictor thanks man ...what i'm finding difficult to understand is how to implement filters in this project and how many filters to use...filter designing is a little difficult for me to understand...i'l be grateful if you can help me with that..and one thing more...for speech compression lpc is the best way or there is some better and easy alternative...??
• 

  Predictor

  pulkit.143

  hey predictor thanks man ...what i'm finding difficult to understand is how to implement filters in this project and how many filters to use...filter designing is a little difficult for me to understand...i'l be grateful if you can help me with that..and one thing more...for speech compression lpc is the best way or there is some better and easy alternative...??

  Sorry, filter design is not my area of expertise. I'm in the pattern recognition business.
  
  
  -Will Dwinnell
  Data Mining in MATLAB
• 

  pulkit.143

  i'm facing a problem...when i'm plotting the fft of the input speech through fft function in matlab i'm not getting the frequency graph..instead m getin smthin els in the complex plane tats a little round in shape...why is that???
• 

  just2rock

  pulkit.143

  i'm facing a problem...when i'm plotting the fft of the input speech through fft function in matlab i'm not getting the frequency graph..instead m getin smthin els in the complex plane tats a little round in shape...why is that???

  Pulkit,
  W"ll definately answer all questions, but please stop using sms terms in forum😔
• 

  Predictor

  pulkit.143

  i'm facing a problem...when i'm plotting the fft of the input speech through fft function in matlab i'm not getting the frequency graph..instead m getin smthin els in the complex plane tats a little round in shape...why is that???

  
  I'm not sure what you mean by "the frequency graph": both the phase and magnitude are indexed by frequency, in the output of a Fourier transform. If you are simply doing something like:
  
  B = fft(A);
  figure, plot(B)
  
  
  ...then you will probably get more useful results doing something like:
  
  B = fft(A);
  figure, plot(abs(B))
  figure, plot(angle(B))
  
  Also, please take the time to type out your actual message? Your shorthand is difficult to follow.
  
  
  -Will Dwinnell
  Data Mining in MATLAB
• 

  pulkit.143

  thank you predictor..it helped..but what is the third line for?? i understood the first two that are for the fft plot....and now what i'm doing is that i'm taking the cepstrum of the signal and subtracting it from the original signal to get the pitch so that i can compare it with the stored sample..but i dont know exactly that how to compare...and please tell me if i'm going wrong somewhere..may be there is some other way of comparing speech parameters..
• 

  pulkit.143

  hey predictor...what i'm mainly concerned about is the analysis part of the project...how do i design an algorithm for that...???? and what are all the parameters of speech that i'll b comaparing ..??? till now i have plotted the pitch of the signal using cepstrum..
• 

  Predictor

  You could save one (or more) examples of each known speaker's voice, and compare the new case to all of those, looking for the closest match. Which method of determining the similarity of two sampled voices is most accurate can only be determined by experimentation.
  
  One obvious thing to try is the average absolute difference between the FFT magnitudes.
  
  You might try using something simple. A fuzzy logic system was once built, to recognize spoken digits, which used only sample counts from the digitized waveform for each of 24 zones (4 amplitude segments by 6 time segments).
  
  
  -Will Dwinnell
  Data Mining in MATLAB
• 

  pulkit.143

  actually i was thinking of finding out the pitch of the input signal and the stored sound through lpc filtering and then comapring both ..?? what do you think??
• 

  Predictor

  pulkit.143

  actually i was thinking of finding out the pitch of the input signal and the stored sound through lpc filtering and then comapring both ..?? what do you think??

  That sounds like a good idea, too. What really matters is how well any of the approaches work, when used in the complete solution.
  
  
  -Will Dwinnell
  Data Mining in MATLAB
• 

  pulkit.143

  predictor ..can u refer me some book which will be helpul in understading the models for this project so that i can design the algorithm ...and understand the concepts involved and also how can i implement it in matlab..thanks...
• 

  Predictor

  pulkit.143

  predictor ..can u refer me some book which will be helpul in understading the models for this project so that i can design the algorithm ...and understand the concepts involved and also how can i implement it in matlab..thanks...

  
  I recommend any of the following:
  
  "Computer Systems That Learn" by Weiss and Kulikowski (ISBN-13: 978-1558600652)
  
  "Pattern Recognition (Third Edition)" by Theodoridis and Koutroumbas (ISBN-13: 978-0123695314)
  
  "Pattern Classification (2nd Edition)" by Duda, Hart, and Stork (ISBN-13: 978-0471056690)
  
  
  -Will Dwinnell
  Data Mining in MATLAB
• 

  pulkit.143

  hey man...
  i aquired the sound , then i plotted its fft, then i passed it through lpc filter and again plotted the compressed sound waveform...but the audio quality in the compressed sound is highly compromised...how can i improve on that or how can i increase the bit rate...
• 

  pulkit.143

  hey predictor,
  can you please tell me that how to use the burg's model in matlab for power spectrum estimation...???
• 

  mohanadadnan

  thanx very mych for all