Working shifts in the aviation industry and living in a city center that can be noisy, my best investment was sleeping earbuds named Bose sleepbuds (v2).

It’s just earbuds that you don’t feel and can sleep on your side without pain, they only play white noises.

Now I’m waiting for the Ozlo Sleep which are basically the v3 of the Bose sleepbuds.

Those things saved my sanity when working night shifts.