System and method for controlling a home assistant device include: receiving an audio input; performing speaker recognition on the audio input; in accordance with a determination that the audio input includes a voice input from a first user that is authorized to control the home assistant device: performing speech-to-text conversion on the audio input to obtain a textual string; and searching for a predefined trigger word for activating the home assistant device in the textual string; and in accordance with a determination that the audio input includes a voice input from the home assistant device: forgoing performance of speech-to-text conversion on the audio input; and forgoing search for the predefined trigger word.