The soothing, steady hum of brown noise, which is similar to white noise but has a lower and deeper sound quality, is gaining popularity online, especially among people with attention-deficit/hyperactivity disorder, Dani Blum reported. Some say brown noise
helps them feel calm, focused and less stressed; others say it soothes them to sleep. But for some, the constant hum of brown noise could be distracting or anxiety provoking. There’s most likely no harm to listening to brown noise for extended periods of time (unless you’re listening at unsafe volumes), experts say, but there’s not much scientific studies showing the benefits yet either... If the rumbly buzz of brown noise brings you calm, listen to your heart’s content!