Headphone port on Macbook quits working after a few seconds

I've searched through many headphone port complaints but I just haven't been able to find one quite like mine.

Mine works. And then it doesn't. Plug it back in and it works again, for two seconds, and then it doesn't. Round and round it goes. I'm not sure if this is a settings issue, but I'm guessing it means something is physically broken inside. I have tried various headphones and speakers. I've had my Macbook about 3 years, it's been 9 months to a year since it stopped working right. I just assumed it was broken but my husband said I should make sure it's not a setting or other fixable issue.

Thoughts? Thanks!