15. One or more non-transitory computer readable media comprising executable code that, when executed, cause one or more computing devices to perform a process comprising: obtaining (1) a model for detecting data representing a keyword in an audio sample and (2) a first detection threshold corresponding to the model, wherein a detection score greater than the first detection threshold indicates that data representing the keyword is present in the audio sample, and wherein the detection score is computed using the model and the audio sample; determining a first cost of computing a first incorrect detection hypothesis, wherein the first incorrect detection hypothesis corresponds to a detection score satisfying the first detection threshold for input in which data representing the keyword is not present, and wherein the first cost represents a cost of computing the first incorrect detection hypothesis at least a predetermined time period following computation of a prior incorrect detection hypothesis; determining a second cost of computing, within the predetermined time period following the first incorrect detection hypothesis, a second incorrect detection hypothesis, wherein the second cost is different than the first cost; determining a second detection threshold based at least partly on the first and second costs; transmitting the second detection threshold to a client device; receiving audio data from the client device, wherein the client device transmits the audio data based at least partly on a detection score, determined using the audio data, satisfying the second detection threshold; and performing automatic speech recognition on at least a portion of the audio data to determine that data representing the keyword is present in the audio data, wherein the keyword comprises a word likely indicating device-directed speech.
15. One or more non-transitory computer readable media comprising executable code that, when executed, cause one or more computing devices to perform a process comprising: obtaining (1) a model for detecting data representing a keyword in an audio sample and (2) a first detection threshold corresponding to the model, wherein a detection score greater than the first detection threshold indicates that data representing the keyword is present in the audio sample, and wherein the detection score is computed using the model and the audio sample; determining a first cost of computing a first incorrect detection hypothesis, wherein the first incorrect detection hypothesis corresponds to a detection score satisfying the first detection threshold for input in which data representing the keyword is not present, and wherein the first cost represents a cost of computing the first incorrect detection hypothesis at least a predetermined time period following computation of a prior incorrect detection hypothesis; determining a second cost of computing, within the predetermined time period following the first incorrect detection hypothesis, a second incorrect detection hypothesis, wherein the second cost is different than the first cost; determining a second detection threshold based at least partly on the first and second costs; transmitting the second detection threshold to a client device; receiving audio data from the client device, wherein the client device transmits the audio data based at least partly on a detection score, determined using the audio data, satisfying the second detection threshold; and performing automatic speech recognition on at least a portion of the audio data to determine that data representing the keyword is present in the audio data, wherein the keyword comprises a word likely indicating device-directed speech. 18. The one or more non-transitory computer readable media of claim 15 , wherein at least one of the first or second costs is based at least partly on contextual information.