Is it possible to create a phoneme recognizer with HTK using the VoxForge Acoustic models?

I tried it with two different approaches:

a) using just the 44 (or so) phonemes without triphone

b) using all triphones (from the file 'tiedlist').

Here is what I did for approach a)

1.

downloaded the models: Julius_AcousticModels_16kHz-16bit_MFCC_O_D_(0_1alpha-build541).zip

2. create a model list from the file 'tiedlist' by leaving just the single phonemes and removing triphones etc.

it looks like this and is called 'phonemlist':

b
d
f
g

3.

create a dictionary from the file 'phonemlist'. It looks like this:

b b
d d
f f
g g
k k

4.

create a grammar and wordnet.

Grammar looks like this:

$PHON  =  b | d | f | g | k | l | m | n | p | r | s | t | v | w | y | z | aa | ae | ah | ao | aw | ax | ay | ch | dh | dx | eh | er | ey | hh | ih | ix | iy | jh | ng | ow | oy | sh | th | uh | uw | zh ;
( [sil] < $PHON [sp]  > [sil]  )

Create the wordnet with HParse gram wordnet

5. I took a recording from the YOHO database and made the feature extraction with the following:

The title of the file says what is spoken in the file.

------------------

HCopy -T 1 -D -A -C confighcopy 26_81_57.wav 26_81_57.mfc

HTK Configuration Parameters[12]
  Module/Tool     Parameter                  Value
#                 SOURCERATE                 16000
#                 SOURCEFORMAT                WAVE
#                 NUMCEPS                       12
#                 CEPLIFTER                     22
#                 NUMCHANS                      26
#                 PREEMCOEF               0.970000
#                 USEHAMMING                  TRUE
#                 WINDOWSIZE         250000.000000
#                 SAVEWITHCRC                 TRUE
#                 SAVECOMPRESSED              TRUE
#                 TARGETRATE         100000.000000
#                 TARGETKIND              MFCC_0_D

------------

6.

try the recogniser:

----------------------

HVite -A -D -T 1 -H macros -H hmmdefs -C config -l * -i recout.mlf -w wordnet -p -40.0 -s 5.0 main.dict phonemlist 26_81_57.mfc

HTK Configuration Parameters[10]
  Module/Tool     Parameter                  Value
#                 NUMCEPS                       12
#                 CEPLIFTER                     22
#                 NUMCHANS                      26
#                 PREEMCOEF               0.970000
#                 USEHAMMING                  TRUE
#                 WINDOWSIZE         250000.000000
#                 SAVEWITHCRC                 TRUE
#                 SAVECOMPRESSED              TRUE
#                 TARGETRATE         100000.000000
#                 TARGETKIND          MFCC_0_D_N_Z

Read 44 physical / 44 logical HMMs
Read lattice with 48 nodes / 217 arcs
 WARNING [-8232]  ExpandWordNet: Pronunciation 1 of sp is 'tee' word in HVite
Created network with 95 nodes / 264 links
File: 26_81_57.mfc
sil ae sp ow aw sp m ae sp hh aw uh ow ah ax uw sp ah sp eh sp m ow sil  ==  [5571 frames] -61.2614 [Ac=-340287.4 LM=-1000.0] (Act=93.0)
-------------------------

Ok, so it seems like it didn't work quite well.

It should recognise "twenty six, eighty one, fifty seven", in phonemes.

And it recognized: sil ae sp ow aw sp m ae sp hh aw uh ow ah ax uw sp ah sp eh sp m ow sil

With variant b) (using triphones), it recognized  "sil ae+v sil ao+r ae+d n-th ae+v sil s-ae+ng m-uw+n m-uw+n ao+r ae+d ow-n+l sil dx-ax sil ae+n sil dx-ax ax+n sil"  from the same file.

Is there some fundamental thing I am doing wrong? Or some parameters I can tweak or so?

Thank you for any help!

--- (Edited on 11/17/2009 6:44 am [GMT-0600] by ) ---