Recurring sound problem

So sometimes my macbook will switch to like optical mode instead of the internal speakers and to fix it I would just plug headphones in then remove right away. This used to work, but for some reason the problem has gotten worse.

The headphone trick still works, but it only stays that way for like 30 seconds until the computer switches back to optical mode. Does anyone know of a permanent fix for this or know why my macbook keeps doing this?

I'd really like to hear things. Thanks.