I'm posting this on Voxforge since the issue might be with me, HTK, Julius or elsewhere. Here's what happens :
In my speaker-dependent grammar I have about 8 sentences (of about 100) that start with WORD and have a second part QUIT, STATUS, TIME, etc. Seven of the eight are recognized perfectly 100% of the time and one of them WORD RESTART bombs out with "hypothesis stack exhausted" at least 50% of the time. Julius never thinks it is something else, it just runs out of suggestions. Recognition of the grammar as a whole is very close to 100%.
Now it gets strange. If my prompt is WORD RESTART and I say WORD ESTART or WORD START (neither of these is in my grammar) then it returns WORD RESTART 100% right all the time.
It seems something is happening to my Rs. I also have a problem occasionally with ZERO and ROMEO.
I'm trying to develop a theory/hypothesis list.
1. I am not saying R at all even though I think I am (some French rolling Rs might come in handy). I don't think I am saying W.
2. My mike (bluetooth) is not hearing R even though I am saying it
3. The recording tries to decipher the R but it gets mixed in with background noise
4. It is recorded but HTK misses it
5. HTK gets it but Julius misses it.
Does R already have a rap sheet? Any suggestions how I can narrow this down? I have the workaround, just omit the R while enunciating, but it would be good to have an explanation here. It's pretty hard to design a sensible grammar constantly trying to avoid Rs.
--- (Edited on 1/13/2010 8:09 am [GMT-0600] by colbec) ---
--- (Edited on 1/13/2010 8:15 am [GMT-0600] by colbec) ---
>Does R already have a rap sheet? Any suggestions how I can narrow
My first guess would be that you need more speech audio containing words that have 'r's in them...
Are you using the VoxForge acoutic model? If so, you might need to adapt it to your voice using sentences containing lots of 'r's or submit your own prompt recordings and I can include them in the next acoustic model run.
--- (Edited on 1/19/2010 2:06 pm [GMT-0500] by kmaclean) ---