All Smart Audio Alerts for Calendars except Alerts to join meetings via an app link can be replayed. Smart Audio Alerts can be replayed by pressing the Play button on the Pod within 10 secs of the Alert playing.
Note that pressing the Play button for a meeting app link Alert joins you to the meeting.
How to Cancel Smart Audio Alert for Calendar
Turn off alerts for any or all of the events in the calendar, by disabling the event (as shown below). Disabled alerts do not play while driving.
Alerts that are not disabled in the app, can be canceled by pressing the Skip/No button on the Pod.