Can anyone please tell me how I can set my phone up so I get a discreet beep in my earpiece if someone texts me during a call? This has came as standard on most of my previous handsets but for some reason not on the S4. I'm using gosmspro as my text message app & I tried looking through the many settings in there. I did find what I thought was the answer only for it to play my message alert tone really loud down my ear. Any help would be much appreciated.