26. The computer-implemented method of claim 21 , further comprising: before determining that the particular candidate hotword satisfies one or more hotword suitability criteria, receiving audio data that encodes an utterance of one or more words, at least a portion of which represent the particular candidate hotword.
21. A computer-implemented method comprising: receiving, using a microphone of a computing device, a request to designate a particular candidate hotword that is not currently designated as a hotword, as a hotword; determining that the particular candidate hotword satisfies one or more hotword suitability criteria; in response to determining that the particular candidate hotword satisfies one or more hotword suitability criteria, designating the particular candidate hotword as a custom hotword; after designating the particular candidate hotword as a custom hotword, determining that subsequently received audio data received using the microphone of the computing device includes sounds that are characteristic of an utterance of the custom hotword; in response to determining that the subsequently received audio data includes sounds that are characteristic of an utterance of the custom hotword: providing, on a display of the computing device or using a speaker of the computing device, an indication that the custom hotword was detected; and causing the computing device to enter a ready state for receiving and processing voice commands uttered after the utterance of the custom hotword.