Abstract: A user interface device for an intelligent automated assistant service uses a plurality of audio data paths that can be selectively switched to operate in a privacy mode. There is provided a first audio data input path between the audio input subsystem and an internal buffer; a first audio data output path between the internal buffer and the first communications subsystem; a second audio data output path between the internal buffer and the second communications subsystem; and a first audio data bypass path between the audio input subsystem and the second communications subsystem. In a first state, the first audio data input path directs audio data to the internal buffer, and to the first and second audio data output paths. In a second state, the first audio data input path is terminated and audio data is directed to the second communications subsystem on the first audio data bypass path.