I recently had this discussion with a student about gaining an intuition about tempo ranges, and refining one's awareness of specific tempos.
I recommended something that I know Steve Vai apparently did, which is to go to sleep with a metronome on. The purpose being, to be able to memorize a specific speed in bpm (beats per minute) and recall it at will.
Having said that, I will say that while I have tried that long ago - just for the sake of it - I can't do it for no other reason than I've always been an insomniac. I suggest one try a tempo deliberately slower than 60 bpm, to avoid the "clock ticking" phenomenon, but to also try to use a tempo that is a subdivision of a song one is very familiar with.
While I never successfully managed to sleep with a metronome on, I would recount that as a kid I would often "mainline" songs that I like. As in, as a 12 year old in those days set my cassette player to repeat a particular song I liked over and over and over and over. Not with any kind of intent - I didn't consider myself "a musician" then - but because I really liked the music. I looked forward to hearing exact moments in a song - later to realize the things that happen on a time scale measured in milliseconds - a bent note, a snare accent, any number of things. In doing so I believe the familiarity of being able to ponder the rhythmic events in a song on a minute scale helped me later on as a professional musician.
