When my ex and I first began cohabitating, the clock radio alarm was on my side of the bed. He soon learned that this was folly. Every morning at 7am, the clock would make a distinctive "click" a split-second before the radio would engage, and in that fraction of a heartbeat, I not only rolled over, but I found the off button (rather than the snooze) and turned it right the hell off and went back to sleep.
We were in college at the time, and that meant he was late or slept right through some things (me, too) and he ended up moving the clock to his side of the bed. He learned quickly enough that I can vault myself out of a tangle of covers (or encroaching male) and slap the snot out of a clock between the click and the start of a song, return to my side and be fast asleep before he even registered that there had been an elbow in his throat.