Try
Dim myjoContext As JavaObject
myjoContext.InitializeContext
Dim myjoAudio As JavaObject = myjoContext.RunMethod("getSystemService", Array("audio"))
' 0 = RINGER_SILENT
myjoAudio.RunMethod("setRingerMode", Array(0)) ' or Array(1) for RINGER_VIBRATE or Array (2) for RINGER__NORMAL
Catch
LastException.Message
End Try