I am trying to do a project with voice recognition. Which platform is better for voice recognition Arduino or Raspberry Pi? And why?
I'd go so far to say that the computational power of an arduino would be quite a limit to voice recognition. Bitvoicer for example uses the arduino to sample the speech but not to process and recognice it. It sends the stream to a more powerful system to do the recognition part.
The Pi on the other hand is powerful enough to do all the processing itself as this excellent answer points out.
If the voice commands to be distinguished are very rudimentary only (as your other question suggests) it might be possible to get something done with the arduino. But I think that it will be bordering self mortification.