What's Welsh for Ear Worm?

We were walking home from dinner a couple nights a go, stuffed to the gills with Lebanese food, too full to have a proper conversation.

I hear a faint humming, "ah hmmmm, ah hmmmm" coming from Larry's direction. Was my tinitus playing tricks on me?

"Are ya humming a Glyn song?"

"I think I just might be," he said, blushing a little.