Methods and apparatus for retrieving audio information using content and speaker information

Methods and apparatus are disclosed for retrieving audio information based on the audio content as well as the identity of the speaker. The results of content and speaker-based audio information retrieval methods are combined to provide references to audio information (and indirectly to video). A query search system retrieves information responsive to a textual query containing a text string (one or more key words), and the identity of a given speaker. An indexing system transcribes and indexes the audio information to create time-stamped content index file(s) and speaker index file(s). An audio retrieval system uses the generated content and speaker indexes to perform query-document matching based on the audio content and the speaker identity. Documents satisfying the user-specified content and speaker constraints are identified by comparing the start and end times of the document segments in both the content and speaker domains. Documents satisfying the user-specified content and speaker constraints are assigned a combined score that can be used in accordance with the present invention to rank-order the identified documents returned to the user, with the best-matched segments at the top of the list.