1. A computer implemented information retrieval system for searching a corpus, the system comprising: a computer; a scoring module configured to, for each of one or more searches of at least a subset of the corpus, generate a confidence score for each of one or more putative occurrences of a search query in the at least a subset of the corpus; a threshold module configured to adjust a threshold to maintain a consistent user experience across the one or more searches according to a consistency criterion, wherein the threshold is adjusted according to at least one of a duration of the at least a subset of the corpus or an audio quality of the at least a subset of the corpus; and a display module configured to display putative occurrences of the search query having a confidence score greater than the threshold; wherein the consistency criterion is selected from the group consisting of a constant number of false alarms in the putative occurrences of the search query for each of the one or more searches, a constant false alarm rate in the putative occurrences of the search query for each of the one or more searches, a constant number of true occurrences of the search query for each of the one or more searches, a constant precision value in the putative occurrences of the search query for each of the one or more searches, a constant number of missed occurrences of the search query for each of the one or more searches, and a constant recall value in the putative occurrences of the search query for each of the one or more searches.