So midterms have started here at the University of Washington (already, I know!) and I’m starting to notice more stressed-out study sessions. Around this time of year I always think about all the crazy study hints and tips I’ve heard over the years. (My personal favorite tip is to drink sage tea while I’m reading over notes–it’s been shown to help improve memory.) But one tip that people often share is that listening to white noise can help you concentrate while studying. Being the sort of person I am (read: huge nerd) I decided to set out and see what the research has to say about it.
First things first: some noises can definitely be bad for learning. For example, one study which compared schools near major airports (which are a big source of noise pollution) and some which were not found that children who were in the noisier environment had reduced reading comprehension. An earlier, similar study showed that students in classrooms near a very noisy train track did worse academically than those that were not.
And noisy environments are bad for concentration, too. One survey of office workers found that 99% of participants were bothered by noises like ringing telephones and conversations, and that the negative effects of these noises didn’t fade over time. And we know that some types of speech noise–especially half of a telephone conversation–are incredibly distracting.
Ok, so we know that some noise can hurt both learning and concentration… so why fight fire with fire? Wouldn’t listening to white noise just be more of the same? Or even worse?
Well, not necessarily. The really distracting thing about noise is that it’s not predictable. It’s pretty easy to “tune out” a clock ticking because your brain can figure out when it’s going to tick again. When a new noise suddenly starts, however, or keeps happening in an unpredictable way, like a faucet dripping juuuust out of rhythm, your attention snaps to it. There’s actually a special set of “novelty detector neurons” that are looking for any new types of sounds that might show up. There are two ways to avoid this happening. One is to make sure that all your environmental sounds are ones you can easily ignore… or you can cover them up. And white noise is very effective at covering up other noises.
White noise is random noise that covers a wide frequency spectrum, usually 20 to 20,000 Hz. That means that other sounds that are the same volume or quieter than the white noise can’t “get thorough”. As a result, you don’t hear anything surprising, your novelty detector neurons stay quiet, and you can focus on what you’re doing. And don’t take my word for it: this study shows that students who listened to a recording of office noises masked with white noise preformed much better on tasks then those who listened to the office noises unmasked.
Now, keep in mind, just because a noise is “white” doesn’t mean it’s good for you. Volume, for one thing, is very important. Exposing rats to 100-dB white noise for 45 minutes was enough for them to undergo measurable stress-induced neurological changes. To be fair, that’s about as loud as a power mower but it does takes you out of the “relaxed concentration” range. So grab your headphones and favorite white noise source (if you’ve no other options, a radio set to static will work just fine) but remember to keep the volume down!