If you’ve ever been to talk therapy, you’ve probably encountered the Dohm Sound Conditioner: a chubby, off-white cylinder that looks straight out of the 1970’s. Psychotherapists place them in hallways to drown out the sound of voices, so patients can’t hear one another. The sound produced by the Dohm is vaguely reminiscent of a laptop fan, or a forced-vent air conditioner (evoking different associations for everyone, the Dohm is an auditory Rorschach of sorts). The machine’s true purpose, though, was to cure its inventor’s insomnia, and scientists say it works because it tricks the brain out of being distracted by other ambient noise. We're putting one in our Amazon cart as we speak. Have you tried the Dohm or another white noise machine? Give us your review in the comments.