American vs British soundtracks - is there a difference?

If I’m watching a comedy on BBC America, or a British comedy on PBS, it sounds like the laughtrack is much louder than what you would find on an American sitcom. To my ears, it seems seems like British laughtracks have a different sound (more like “arr arr arr” compared to an American “ha ha ha”), and they stop quickly, rather than ramping down.

Are my perceptions correct?