The noise sounds like wind, or heavy rain, or the steady hum of an airline jet. It sounds like water rushing somewhere in the distance, like a gentle fan ruffling currents of cool air. It’s soothing, steady, slightly rumbly.
Welcome to the cult of BROWN NOISE, a sometimes hazily-defined category of neutral, dense sound that contains every frequency our ears can detect. Brown noise is like white noise but has a lower, deeper quality. It gained a fervent following over the summer, picking up speed in online A.D.H.D. communities, where people made videos of their reactions to hearing it for the first time. Many said it allowed their brains to feel calm, freed from an internal monologue. Some invited their viewers to try it too, and commenters chimed in, claiming that brown noise was not only a tool to help them focus, but could relieve stress and soothe them to sleep.