I just bought this very exiguous device called the Magicteam Sound Machine. It generates 20 non-looping sleep sounds: white noise, brown noise, pink noise, blue noise, fan, brook, rain, ocean, bird and bonfire.
I got it specifically for the brown noise generator, which has been established as a sleep aid. I tried it out last night.
Plugged it in, set for brown noise, cranked it up and placed it a foot away from my pillow. Instantly, the noise that I endure throughout the night such as traffic out on the highway through my open window, my neighbors air-conditioner below my window, and my refrigerator noise, disappeared.
I had a great sleep, amazing dreams, and my watch gave me a sleep score of 80. I highly recommend this $26 device!