10. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: receiving, by a second stage hotword detector of a multi-stage hotword detection system that includes at least a first stage hotword detector and the second stage hotword detector, audio data that corresponds to an initial portion of an utterance; determining, by the second stage hotword detector, a likelihood that the initial portion of the utterance includes a hotword; determining, by the second stage hotword detector, that the likelihood that the initial portion of the utterance includes the hotword satisfies a threshold; and in response to determining that the likelihood satisfies the threshold, transmitting, by the second stage hotword detector and to the first stage hotword detector, a request for the first stage hotword detector to cease providing additional audio data that corresponds to one or more subsequent portions of the utterance.
10. A system comprising: one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: receiving, by a second stage hotword detector of a multi-stage hotword detection system that includes at least a first stage hotword detector and the second stage hotword detector, audio data that corresponds to an initial portion of an utterance; determining, by the second stage hotword detector, a likelihood that the initial portion of the utterance includes a hotword; determining, by the second stage hotword detector, that the likelihood that the initial portion of the utterance includes the hotword satisfies a threshold; and in response to determining that the likelihood satisfies the threshold, transmitting, by the second stage hotword detector and to the first stage hotword detector, a request for the first stage hotword detector to cease providing additional audio data that corresponds to one or more subsequent portions of the utterance. 15. The system of claim 10 , wherein the first stage hotword detector is speaker and language independent and the second stage hotword detector is speaker and language dependent.