Poor quality rest over an extended period of time is related to hypertension, cardiovascular disease, weight gain, type 2 diabetes, as well as specific kinds of cancer. Noises during the night could wake you up, and a fragmented night's sleep is less rejuvenating. Also sounds that do not wake you up have subconscious results on rest by changing the time we invest in particular rest phases. Sleep phases are the various kinds of sleep we cycle through each night, varying from lighter phases to deep