You can change it in Sounds to something louder than the swoosh.If I'm in iMessage when a message comes in it will not sound the alert just a small swoosh or something but its barely noticeable if I'm not waiting for a immediate response.. My droid would ring no matter what..
i have Digital as my alert for texts,it gives the same sound for iMessages and its quite loud......Not while you are actually in message. If your phone is on message and active, you will still get the swoosh. That's how my wife got those 2 or 3 messages by me last night.
ah yes i see what you mean now i give it some thought,i do get the swoosh noise if I'm actually messaging,i have my volume right up and i do hear it fine,OK, but while you are in the program and the phone is active? Because I use a different tone too (I think bells) for messages and if I happen to be sending a text and receive one around the same time, I get a swish.