Hey Brian,
don't worry about having a disability. I was born with Cerebral Palsy and I'm very good at fixing and using computers.
Your Advent is a laptop? Your sound driver may be corrupt or the on-board sound chip may be fried.
You have a few options on fixing this:
1) Update and reinstall the Advent's sound drivers
2) Replace the motherboard
or
3) Purchase a low cost USB sound device