1) You can tap the mike for it to listen, say something, then tap the mike again to make it stop listening. This is useful in a noisy environment when you don’t want the mike to pick up someone else’s conversation.
2) You can change how long the mike waits when you pause while speaking before it automatically turns off. Tap the gear (“
“) Bot Settings icon, then tap the “App Settings” button. The setting is called “Microphone silence timeout in milliseconds”.