Background noise may wreck concentration and give you ulcers. More specifically to how it affects learning:
Several studies have indicated that stress resulting from ongoing white noise can induce the release of cortisol, a hormone that helps to restore homeostasis in the body after a bad experience. Excess cortisol impairs function in the prefrontal cortex—an emotional learning center that helps to regulate “executive” functions such as planning, reasoning and impulse control. Some recent evidence indicates that the prefrontal cortex also stores short-term memories. Changes to this region, therefore, may disrupt a person’s capacity to think clearly and to retain information.
A good reason to study at the library rather than in the laundromat.
