This makes me wonder about 'white noise'? I finally caved and bought a non looping white noise machine after years of being woken up by car engines, ambulances, god forsaken LEAF BLOWERS cranking up at 7am every morning. Now, I notice I often sleep until my alarm.

I would think that constant white noise would have a positive, or at least no negative impact but I have no evidence, and googling only pulls up intermittent noise studies.