He you are the android mobile users, then there is possibility that when you connect gprs or wifi or 3g you can hear auto matic tones ringing. Its the basic issue for novice users. The solution is simple if you know what is making such problem. There are applications in your mobile which uses nitification alerts. Facebook is basic application that comes with sony ericsson,samsung based android mobiles. Where faceebook uses notification alert ringtones by default. Basic mobile tone will be used for this. To prevent this notification ringtone sound, you to to facebook mobile application click settings notifications , no sound. Thats it. If you want to temporarily shut all the notification sounds from entire device, put your mobile in silent or vibration alert mode. If you wear headset you can hear ringtone sounds , only if you use non silent and vibration modes.