A computer-implemented method, comprising: at an electronic device with one or more processors and memory: while in a first state, determining whether audio input includes speech directed to a digital assistant; while in a second state, determining whether audio input includes speech directed to invoking the digital assistant, wherein the second state is a lower power state than the first state; receiving, from a user, a first speech input directed to the digital assistant; providing a first response based on the first speech input, wherein the first speech input is associated with a first speaker profile; initiating a first session window, wherein the first session window is associated with a first variable duration; while the first session window is active, detecting audio in the first state; receiving a second speech input during the first session window, wherein the second speech input is associated with a second speaker profile; in accordance with a determination that the first speaker profile and the second speaker profile are associated with a same user, increasing the variable speech threshold; in accordance with a determination that the second speech input includes speech directed to the digital assistant: initiating a second session window associated with a second variable duration and reducing a volume level associated with a currently playing media item, wherein the first and second session windows correspond to a duration of time by which the digital assistant awaits one or more forms of re-engagement from the user and wherein the second variable duration is associated with the variable speech threshold and is extended when the variable speech threshold exceeds a predetermined speech threshold; while the second session window is active, detecting audio in the first state; and in accordance with audible output criteria not being satisfied: forgoing providing an audible output at a time corresponding to an end of the second variable duration, and raising the volume level associated with the currently playing media item at the time corresponding to the end of the second variable duration, wherein the audible output criteria are not satisfied if a media item is playing at the electronic device; and while the first session window and second session window are inactive, detecting audio in the second state. while in a first state, determining whether audio input includes speech directed to a digital assistant; while in a second state, determining whether audio input includes speech directed to invoking the digital assistant, wherein the second state is a lower power state than the first state; receiving, from a user, a first speech input directed to the digital assistant; providing a first response based on the first speech input, wherein the first speech input is associated with a first speaker profile; initiating a first session window, wherein the first session window is associated with a first variable duration; while the first session window is active, detecting audio in the first state; receiving a second speech input during the first session window, wherein the second speech input is associated with a second speaker profile; in accordance with a determination that the first speaker profile and the second speaker profile are associated with a same user, increasing the variable speech threshold; in accordance with a determination that the second speech input includes speech directed to the digital assistant: initiating a second session window associated with a second variable duration and reducing a volume level associated with a currently playing media item, wherein the first and second session windows correspond to a duration of time by which the digital assistant awaits one or more forms of re-engagement from the user and wherein the second variable duration is associated with the variable speech threshold and is extended when the variable speech threshold exceeds a predetermined speech threshold; while the second session window is active, detecting audio in the first state; and in accordance with audible output criteria not being satisfied: forgoing providing an audible output at a time corresponding to an end of the second variable duration, and raising the volume level associated with the currently playing media item at the time corresponding to the end of the second variable duration, wherein the audible output criteria are not satisfied if a media item is playing at the electronic device; and forgoing providing an audible output at a time corresponding to an end of the second variable duration, and raising the volume level associated with the currently playing media item at the time corresponding to the end of the second variable duration, wherein the audible output criteria are not satisfied if a media item is playing at the electronic device; and while the first session window and second session window are inactive, detecting audio in the second state.