A method for a playback device comprising one or more speakers, the method comprising: capturing, via one or more microphones, a first portion of a first voice input; detecting, within the first portion of the first voice input, a wake word for a voice assistant service; the method being characterised by further comprising: when one or more speakers of the playback device are currently idle, activating a tone interference canceller in response to detection of the wake word within the first portion of the first voice input, wherein if one or more speakers of the playback device are currently active in playing audio, the playback device is configured for activating an echo canceller configured to cancel audio output from the one or more speakers in a full-range of a frequency spectrum; in response to detection of the wake word within the first portion of the first voice input and after activating the tone interference canceller, outputting, via the one or more speakers, an audible tone in acknowledgement of the detected wake word, wherein the audible tone has content in one or more known frequency bands in the full-range of the frequency spectrum; capturing, via the one or more microphones, a second portion of the first voice input; and cancelling, via the activated tone interference canceller, the one or more known frequency bands in the audible tone from the captured second portion of the first voice input. capturing, via one or more microphones, a first portion of a first voice input; detecting, within the first portion of the first voice input, a wake word for a voice assistant service; the method being characterised by further comprising: when one or more speakers of the playback device are currently idle, activating a tone interference canceller in response to detection of the wake word within the first portion of the first voice input, wherein if one or more speakers of the playback device are currently active in playing audio, the playback device is configured for activating an echo canceller configured to cancel audio output from the one or more speakers in a full-range of a frequency spectrum; in response to detection of the wake word within the first portion of the first voice input and after activating the tone interference canceller, outputting, via the one or more speakers, an audible tone in acknowledgement of the detected wake word, wherein the audible tone has content in one or more known frequency bands in the full-range of the frequency spectrum; capturing, via the one or more microphones, a second portion of the first voice input; and cancelling, via the activated tone interference canceller, the one or more known frequency bands in the audible tone from the captured second portion of the first voice input. when one or more speakers of the playback device are currently idle, activating a tone interference canceller in response to detection of the wake word within the first portion of the first voice input, wherein if one or more speakers of the playback device are currently active in playing audio, the playback device is configured for activating an echo canceller configured to cancel audio output from the one or more speakers in a full-range of a frequency spectrum; in response to detection of the wake word within the first portion of the first voice input and after activating the tone interference canceller, outputting, via the one or more speakers, an audible tone in acknowledgement of the detected wake word, wherein the audible tone has content in one or more known frequency bands in the full-range of the frequency spectrum; capturing, via the one or more microphones, a second portion of the first voice input; and cancelling, via the activated tone interference canceller, the one or more known frequency bands in the audible tone from the captured second portion of the first voice input.