When you set a notification sound, it's set for all meetings, including any meeting that you're currently in.

1

When you're in a meeting, click Audio options > Audio Settings.

When you're not in a meeting, click Settings on the navigation sidebar.
2

Click Notifications > Meetings.

3

Under Meeting action sounds:

  1. Check A participant joins the meeting and choose a sound from the drop-down list.

  2. Check A participant leaves the meeting and choose a sound from the drop-down list.

4

Click Save.