17. At least one non-transitory computer-readable storage medium comprising instructions that, when executed by at least one processor, execute a method comprising: receiving a search query comprising a phrase comprising at least one in-vocabulary word and at least one out-of-vocabulary word; extracting search terms from the phrase, the search terms comprising at least one in-vocabulary search term and at least one out-of-vocabulary search term; retrieving a first list of occurrences of words for the at least one in-vocabulary search term, the first list retrieved from a first index of words having first timestamps; retrieving a second list of occurrences of sub-words for the at least one out-of-vocabulary search term, the second list retrieved from a second index of sub-words having second timestamps; and merging the first list of occurrences of words and the second list of occurrences of sub-words to create a merged list, wherein merging the first list and the second list comprises evaluating the first timestamps and the second timestamps and adding to the merged list occurrences of combinations of words from the first list and sub-words from the second list that satisfy at least one evaluation criterion, wherein the at least one evaluation criterion comprises a threshold for a difference between first and second timestamps.
17. At least one non-transitory computer-readable storage medium comprising instructions that, when executed by at least one processor, execute a method comprising: receiving a search query comprising a phrase comprising at least one in-vocabulary word and at least one out-of-vocabulary word; extracting search terms from the phrase, the search terms comprising at least one in-vocabulary search term and at least one out-of-vocabulary search term; retrieving a first list of occurrences of words for the at least one in-vocabulary search term, the first list retrieved from a first index of words having first timestamps; retrieving a second list of occurrences of sub-words for the at least one out-of-vocabulary search term, the second list retrieved from a second index of sub-words having second timestamps; and merging the first list of occurrences of words and the second list of occurrences of sub-words to create a merged list, wherein merging the first list and the second list comprises evaluating the first timestamps and the second timestamps and adding to the merged list occurrences of combinations of words from the first list and sub-words from the second list that satisfy at least one evaluation criterion, wherein the at least one evaluation criterion comprises a threshold for a difference between first and second timestamps. 19. The at least one non-transitory computer-readable storage medium of claim 17 , wherein word transcripts are generated by a speech recognition system with a vocabulary of words, and in-vocabulary words are words in the vocabulary of words.