1. A method comprising: receiving, on a computer system, a text search query, the query comprising one or more query words; generating, on the computer system, for each query word in the query, one or more anchor segments within a plurality of speech recognition processed audio files, the one or more anchor segments identifying possible locations containing the query word; post-processing, on the computer system, the one or more anchor segments, the post-processing comprising: expanding the one or more anchor segments; sorting the one or more anchor segments; and merging overlapping ones of the one or more anchor segments; and performing, on the computer system, speech recognition on the post-processed one or more anchor segments for instances of at least one of the one or more query words using a constrained grammar.