If mechanical-keyboard sounds give you an ASMR feeling, and you're in the market for a piece of distraction-free writing software (not that that isn't a commodity feature these days), try Ommwriter (http://www.ommwriter.com) — it has a variety of configurable "pseudorandom typing sounds", meant to be played atop an ambient soundscape using headphones. They're all very pleasing in a way I would now think of as ASMR.