I have a Bush WS6679SIL television but have lost the instruction manual - and I have no sound!

I go into the main menu and select sound. When I drill down listed are the usual sound variables i.e. volume, treble etc but below these is a red box next to 'headphones'.

When I press the red button on my remote the sound variables for the headphones come up. I can faintly hear sound when I turn the volume up to very high so am assuming sound is coming out via the headphones. How do I turn this off?

Any suggestions would be much appreciated.

Many thanks
CJ

Usually when you plug in headphones, it will mute the main speakers. When you remove the headphones, do you hear sound now?