1. A computer program product comprising a non-transitory computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to perform a method comprising: generating a time-marked word list, wherein the time-marked word list is an output of an automatic speech recognition system; generating an index from the time-marked word list, wherein generating the index comprises creating a word loop weighted finite state transducer for each utterance, i; receiving a plurality of keyword queries; and searching the index for a plurality of keyword hits.