title: Speaker adaptation with HTK
body: <p>I am trying to adapt a monophone-based recogniser to a specific speaker. I am using the recipe given in <code>HTKBook 3.4.1 section 3.6.2</code>. I am getting stuck on the <code>HHEd</code> part which I am invoking like sp:   </p>
  
  <p><code>HHEd -A -D -T 1 -H hmm15/hmmdefs -H hmm15/macros -M classes regtree.hed monophones1eng</code>  </p>
  
  <p>The error I end up with is as follows:<br>
  <code>ERROR [+999]  Components missing from Base Class list (2413 3375)<br>
    ERROR [+999]  BaseClass check failed</code></p>
  
  <p>The folder <code>classes</code> contains the file <code>global</code> which has the following contents:<br>
  <code>~b ‘‘global’’<br>
  &lt;MMFIDMASK&gt; *<br>
  &lt;PARAMETERS&gt; MIXBASE<br>
  &lt;NUMCLASSES&gt; 1<br>
    &lt;CLASS&gt; 1 {*.state[2-4].mix[1-25]}</code></p>
  
  <p>The <code>hmmdefs</code> file within <code>hmm15</code> had some mixture components (I am using 25 mixture components per state of each phone) missing. I tried to "fill in the blanks" by giving in mixture components with random mean and variance values but zero weigths. This too has had no effect.  </p>
  
  <p>The hmms are left-right hmms with 5 states (3 emitting), each state modelled by a 25 component mixture. Each component in turn is modelled by an MFCC with EDA components. There are 46 phones in all.</p>
  
  <p>My questions are:<br>
  1. Is the way I am invoking <code>HHEd</code> correct? Can it be invoked in the above manner for monophones?<br>
  2. I know that the base class list (<code>rtree.base</code> must contain every single mixture component, but where do I find these missing mixture components?  </p>
  
  <p>NOTE: Please let me know in case more information is needed.  </p>
  
  <p>Edit 1: The file regtree.hed contains the following:  </p>
  
  <pre><code>RN "models"
  LS "stats_engOnly_3_4"
  RC 32 "rtree"
  </code></pre>
  
  <p>Thanks,<br>
  Sriram</p>