1. A method comprising: receiving data corresponding to a text query from a user; retrieving a spoken document associated with the text query; searching a word index of the spoken document associated with the text query using the text query, to yield first search results; searching a sub-word index of the spoken document associated with the text query using the text query, to yield second search results; and returning, via a computer network and according to the first search results and the second search results, audio segments from the spoken document associated with the text query which correspond to the text query.