A method to be performed by a system comprising a playback device (102, 103), the method comprising: capturing, via one or more microphones (224, 324), first audio within an acoustic environment; determining whether one or more speakers are playing back audio content or are idle; detecting, within the captured first audio content, a wake-word for a voice service; identifying a set of frequency bands of the full audible frequency spectrum in which an audible tone in acknowledgment of the detected wake-word has content; in response to detecting the wake-word for the voice service and before playing an audible tone in acknowledgement of the detected wake-word on the one or more speakers, determining to activate one of: a first sound canceller configured to cancel audio output from the one or more speakers in a full audible frequency spectrum; and a second sound canceller configured to cancel audio output from the one or more speakers in the identified frequency bands of the full audible frequency spectrum in which the audible tone in acknowledgment of the detected wake-word has content, wherein determining to activate one of the first and second sound canceller comprises: when it is determined that the one or more speakers are playing back audio content, activating the first sound canceller; and when it is determined that the one or more speakers are idle, activating the second sound canceller; and in response to detecting the wake-word for the voice service and after activating the one of the first and second sound cancellers, outputting the audible tone in acknowledgement of the detected wake-word via the one or more speakers; capturing, via the one or more microphones, second audio within the acoustic environment, wherein the second audio comprises sound produced by the one or more speakers in outputting the audible tone in acknowledgement of the detected wake-word; and cancelling the audible tone in acknowledgement of the detected wake-word from the captured second audio using the activated first or second sound canceller. capturing, via one or more microphones (224, 324), first audio within an acoustic environment; determining whether one or more speakers are playing back audio content or are idle; detecting, within the captured first audio content, a wake-word for a voice service; identifying a set of frequency bands of the full audible frequency spectrum in which an audible tone in acknowledgment of the detected wake-word has content; in response to detecting the wake-word for the voice service and before playing an audible tone in acknowledgement of the detected wake-word on the one or more speakers, determining to activate one of: a first sound canceller configured to cancel audio output from the one or more speakers in a full audible frequency spectrum; and a second sound canceller configured to cancel audio output from the one or more speakers in the identified frequency bands of the full audible frequency spectrum in which the audible tone in acknowledgment of the detected wake-word has content, a first sound canceller configured to cancel audio output from the one or more speakers in a full audible frequency spectrum; and a second sound canceller configured to cancel audio output from the one or more speakers in the identified frequency bands of the full audible frequency spectrum in which the audible tone in acknowledgment of the detected wake-word has content, wherein determining to activate one of the first and second sound canceller comprises: when it is determined that the one or more speakers are playing back audio content, activating the first sound canceller; and when it is determined that the one or more speakers are idle, activating the second sound canceller; and when it is determined that the one or more speakers are playing back audio content, activating the first sound canceller; and when it is determined that the one or more speakers are idle, activating the second sound canceller; and in response to detecting the wake-word for the voice service and after activating the one of the first and second sound cancellers, outputting the audible tone in acknowledgement of the detected wake-word via the one or more speakers; capturing, via the one or more microphones, second audio within the acoustic environment, wherein the second audio comprises sound produced by the one or more speakers in outputting the audible tone in acknowledgement of the detected wake-word; and cancelling the audible tone in acknowledgement of the detected wake-word from the captured second audio using the activated first or second sound canceller.