The various implementations described herein include methods, devices, and systems for monitoring activity in a home environment. In one aspect, a method performed at a voice-assistant device includes: while operating in an assistant mode, receiving an occupant command to operate in a monitoring mode; in response to the command, transitioning to operating in the monitoring mode; while operating in the monitoring mode, detecting a sound; obtaining a determination as to whether the sound meets one or more monitoring criteria; and in accordance with a determination that the sound meets the one or more monitoring criteria, generating an alert or notification.