title: Speech Recognition using LPC and ANN in Matlab
body: <p>I have audio records of 4 phonemes (a, e, o, u) from 11 people. I trained an ANN using the data from 10 people, and used the other set for testing. I used 14 LPC coefficients of the first period (20ms) of records as features.</p>
  
  <p>The training matrix <code>I</code> has 14 rows and 10 columns for each phoneme. So it is 14*40. Since it is a supervised classification problem, I constructed a target matrix <code>T</code> which is 4*40. It contains ones and zeros where a 1 indicates that the corresponding column in <code>I</code> is from that class.</p>
  
  <p>The test data matrix contains four columns and 14 rows as it contains 4 phonemes from only one person. Let us call it <code>S</code>.</p>
  
  <p>Here is the code:</p>
  
  <pre><code>net = newff(I, T, 15);
  net = init(net);
  net.trainParam.epochs = 10000;
  net.trainParam.goal = 0.01;
  net = train(net, I, T);
  y1 = sim(net, I);
  y2 = sim(net, S)
  </code></pre>
  
  <p>The results are not good even I give the training data as test data (y1).</p>
  
  <p>What is wrong here?</p>