MacBook Pro Mid 2014 Headphone Jack Misbehaving

I have my headphone jack plugged into external speakers, and never remove the jack. A week or so ago, my headphone jack started misbehaving. When I play any audio, one of the following happens.

- Mute

- Distorted sound

- Slightly distorted sound switching to mute (this happened on YouTube after I killed coreaudiod. The youtube sounds was marginal, but when an ad came up it went mute until the main video came back).

I suspect I will need to take my mac into the genius bar to look at, but thought I'd see if anyone had another idea.

Thanks