The Dark Side of White Noise
A review just published in the journal JAMA Otolaryngology questions whether white noise generators — boxes that make static-like sound and are often recommended for relaxation, sleep, masking other noises in the workplace, and tinnitus therapy — may be doing more harm than good. The article is written by neuroscientists affiliated with the University of California San Francisco and with Posit Science, the maker of BrainHQ online brain training.
White noise is a random signal that has equal intensities across frequencies, making it seem ideal for masking or blocking out other noises, for example in the workplace or when trying to sleep. It also is frequently recommended for patients with tinnitus — a persistent ringing in the ears. Tinnitus affects an estimated 50 million Americans and is severe and disabling in an estimated 2 million. There is no cure, nor any widely accepted course of treatment for tinnitus.
White noise generators first gained popularity in the 1960s.
“In the past 50 years, brain scientists have learned a great deal about brain plasticity — how sensory and other inputs change the brain chemically, structurally, and functionally,” said lead author Dr. Mouna Attarha. “Increasing evidence shows that the brain rewires in a negative manner when it is fed random information, such as white noise. Neural inhibition (the ability to filter unimportant information) is reduced; temporal integration times (how quickly the brain processes rapidly changing signals) lengthen; and cortical representations (how information is represented in the brain) lose precision.”
These maladaptive changes in the brain have consequences that, with time, compromise other brain systems, including processing speed, attention, memory, and executive function.
Studies on the impact of unstructured noise on tinnitus further argue for caution in its use as a therapeutic. The authors write that such strategies may be “driving patients’ brains further toward, rather than away from, the pathological disinhibitory state that has long been associated with tinnitus.”
As an alternative form of sound therapy, the authors recommend exploring the use of structured sounds – such as music and speech – to mask or cover the phantom sounds heard in the head by tinnitus patients. This approach may have none of the negative impact on the structural and functional integrity of the brain.
The authors cite a 40-person 2017 study, conducted at Washington University in St. Louis, using auditory exercises found in BrainHQ. Magnetic resonance imaging in that study showed strengthening in areas associated with control and attention. On a qualitative assessment, 50 percent of the participants reported improvement as compared to 15 percent in the control, with no significant difference between groups on self-report cognitive and behavioral measures. BrainHQ productization for tinnitus is subject to further research and regulatory approvals.
The review concludes that a noisy environment produces a noisy brain. Effective resolution of tinnitus will require neuroplasticity-based programs that can remodel and restore the organization of the brain. “Only then,” note the authors, “shall we do no harm.”
