You can choose a different sound for new mail and calendar notifications in Outlook for iOS and Android, or turn the sounds off.
- Tap the menu in the top left corner, and then tap Settings at the bottom.
- Tap Notifications & Sounds on iOS, or Notifications on Android.
- Under Mail or Calendar, tap Sound, and then select the sound you want.
- To turn off sounds, tap Sound, and then select Off.
To turn notifications on or off, or to mute them for a while, see How can I turn push notifications and sounds on or off?.