VITERBI SEARCH
Basic Algorithm
- Time-synchronous
- At each frame, evaluate all transitions
- Make the 'best' transition
- In the end, backtrack to get the best path
Viterbi Beam Search
- Prune hypotheses outside beam
Advantages
- Hypothesis comparison is direct
Limitations
- State space is very large even for moderate-size
applications
- Moderate vocabulary sizes
- Word-internal triphones
- Bigram language model