White Noise Sleep Machines

The white noise machine on my nightstand runs all night and produces a steady hiss that masks the hallway sounds and traffic noise that used to wake me up at 2 AM. Sleep quality difference is noticeable enough that I do not travel without it. Inside the plastic housing, a real fan rather than a speaker playing a loop produces the sound. Air-movement sound is smoother and less repetitive than the digital versions on phone apps because there's no loop point where the audio restarts. I like the simple controls, a single dial that adjusts the tone by changing how much air the fan pushes through the vents. Tactile click of the dial feels deliberate in a way that tapping a phone screen at bedtime doesn't. Technically it's closer to pink noise than white noise because the lower frequencies are emphasized. Deeper tone feels less harsh than the high-frequency static of true white noise. My roommate was skeptical until she slept in our room during a thunderstorm and realized the machine had been running the whole time, masking sounds she would have heard clearly without it.