8. A computer-implemented method comprising: under control of one or more computing devices configured with specific computer-executable instructions, performing automatic speech recognition using audio data received from a client device to obtain a transcript of the audio data, the transcript including first text for the audio data; selecting an intent definition from a plurality of intent definitions, the intent definition selected based on a first textual expression included in the intent definition and on the first text; and generating second text using the first text and the intent definition, wherein the second text corresponds to a second textual expression included in the intent definition, and wherein a portion of the second text matches the first text.
8. A computer-implemented method comprising: under control of one or more computing devices configured with specific computer-executable instructions, performing automatic speech recognition using audio data received from a client device to obtain a transcript of the audio data, the transcript including first text for the audio data; selecting an intent definition from a plurality of intent definitions, the intent definition selected based on a first textual expression included in the intent definition and on the first text; and generating second text using the first text and the intent definition, wherein the second text corresponds to a second textual expression included in the intent definition, and wherein a portion of the second text matches the first text. 12. The computer-implemented method of claim 8 , further comprising selecting additional intent definitions based on a comparison of a current resource level for one of the speech processing system or the client device to a predetermined resource level.