had this issue today. To compound it, the ad sound would bleed over to the next ad sound and both of those bled over to the next... I could not find a way to shut down the ad volume so had to mute my computer sound.
I had it happen to me as well, and I was able to collect some diagnostic info. It is not intentional, and we hope to have it removed asap. Sorry the trouble.
Got a TXU Free nights and solar days ad randomly just now. Didn't see the ad when I looked for it, but definitely heard it. Thought it was probably another tab but saw this which makes me pretty certain its TA: