About sound profiles
You can set notification options for the client, such as vibrate or tone, in the sounds application. The Enterprise Messenger Alert item specifies how you are notified when a contact that you have set an availability notification for becomes available. The Enterprise Messenger New Message item how you are notified of incoming instant messages.
Depending on the sound profile that is set in the sounds application on your device, you might not hear the audible notification that you have set for the client. For more information about sounds, click the Help icon on the Home screen of your BlackBerry® device.