which makes less noise?

If you're still looking for an answer, it would probably be helpful to know what kind of price range you were looking at. I say this because usually the more expensive toys tend to be constructed better out of better materials, which are better at dampening the sound. From a materials point of view, you're going to have to look for something made out of as few pieces as possible (to avoid rattling) and out of softer materials. Check the reviews, they're the best way to gauge intensity and sound. If you don't feel like parsing through all that, you could just take my word and go look at the "Faith" discrete vibrator. hope this helps.