iMessage sound notification

I got an iPhone 6+ at the weekend and have an issued with iMessage. When I receive a message I get the notification my screen, but no sound. In sounds I have set it to play a sound and all notifications are turned on, but obviously when I'm not looking at the screen to see the notification there is no sound to alert me. How do I fix this?

Just to follow up on this: My phone is set for keyboard clicks and locking clicks, but none of these appear to be working either so it seems like a sound issue overall. When I check the volume, it is up, but is there some mute setting over riding everything?

All of those sounds are controlled within "Settings", "Notifications". Go through your Notification settings to make sure that they're turned on for iMessage and for the Phone. This is for iOS 8.1.2 which you should already have on your new iPhone 6+. If after going through notifications settings, you're still not getting the sounds, take the phone back to where you bought if from or to an Apple store and have them check it out.