A method comprising: receiving, on a computer system, a text search query, the query comprising one or more query words; searching, on the computer system, for each query word in the query, within a plurality of speech recognition transcripts generated by performing speech recognition on audio files using a speech recognizer engine configured with a vocabulary, to identify one or more anchor segments, the one or more anchor segments being locations of the speech recognition processed audio files corresponding to low confidence words in the speech recognition transcripts, each anchor segment having a start time and an end time; post-processing, on the computer system, the one or more anchor segments, the post-processing comprising: expanding the one or more anchor segments by: decreasing the start time by a first constant expansion duration and a first expansion duration computed based on a first number of characters in the query before the query word and increasing the end time by a second constant expansion duration and a second expansion duration computed based on a second number of characters in the query after the query word; sorting the one or more anchor segments by start time; and merging overlapping ones of the one or more sorted anchor segments, wherein an anchor segment overlaps with a previous anchor segment when the start time of the anchor segment starts before the end time of the previous anchor segment; performing, on the computer system, speech recognition on the post-processed one or more anchor segments using a constrained grammar comprising at least one out-of-vocabulary word of the one or more query words, the at least one out-of-vocabulary word not being contained in the vocabulary of the speech recognizer engine, the speech recognition identifying segments containing the at least one out-of-vocabulary word of the one or more query words; and outputting, on the computer system, a plurality of search results comprising audio or transcripts of the identified segments containing the at least one out-of-vocabulary word of the one or more query words. receiving, on a computer system, a text search query, the query comprising one or more query words; searching, on the computer system, for each query word in the query, within a plurality of speech recognition transcripts generated by performing speech recognition on audio files using a speech recognizer engine configured with a vocabulary, to identify one or more anchor segments, the one or more anchor segments being locations of the speech recognition processed audio files corresponding to low confidence words in the speech recognition transcripts, each anchor segment having a start time and an end time; post-processing, on the computer system, the one or more anchor segments, the post-processing comprising: expanding the one or more anchor segments by: decreasing the start time by a first constant expansion duration and a first expansion duration computed based on a first number of characters in the query before the query word and increasing the end time by a second constant expansion duration and a second expansion duration computed based on a second number of characters in the query after the query word; decreasing the start time by a first constant expansion duration and a first expansion duration computed based on a first number of characters in the query before the query word and increasing the end time by a second constant expansion duration and a second expansion duration computed based on a second number of characters in the query after the query word; sorting the one or more anchor segments by start time; and merging overlapping ones of the one or more sorted anchor segments, wherein an anchor segment overlaps with a previous anchor segment when the start time of the anchor segment starts before the end time of the previous anchor segment; performing, on the computer system, speech recognition on the post-processed one or more anchor segments using a constrained grammar comprising at least one out-of-vocabulary word of the one or more query words, the at least one out-of-vocabulary word not being contained in the vocabulary of the speech recognizer engine, the speech recognition identifying segments containing the at least one out-of-vocabulary word of the one or more query words; and outputting, on the computer system, a plurality of search results comprising audio or transcripts of the identified segments containing the at least one out-of-vocabulary word of the one or more query words.