How Does the Brain Respond to Hearing Loss?

Researchers from the University of Colorado applied fundamental principles of neuroplasticity — the ability of the brain to forge new connections — in order to determine the ways it can adapt to hearing loss, as well as the consequences of those changes. The research suggests that the portion of the brain devoted to hearing can become reorganized, or reassigned to other functions, even with early-stage hearing loss, and may play a role in cognitive decline. During the study, researchers utilized EEG recordings of adults and children with deafness, and lesser hearing loss, to help gain insight into the ways their brains respond when compared to those with normal hearing. Sound simulation, such as recorded speech syllables, was delivered via speakers, to elicit a response in the form of “brain waves” that originate in the auditory cortex. Researchers have recently discovered that the areas of the brain responsible for processing vision or touch can recruit, or take over areas in which hearing is normally processed, but which receive little or no stimulation in deafness. This is called “cross-modal” cortical reorganization and reflects a fundamental property of the brain to compensate in response to its environment. The researchers from the current study made the discovery that cross-modal recruitment of the auditory function of the brain, by the sense of vision and touch, happens not only in deaf patients, but is also clearly apparent in adult patients with only a mild degree of hearing loss. The results of the study suggest that the portion of the brain used for hearing can become reorganized, even in earliest stages of age-related hearing loss. And, “these compensatory changes increase the overall load on the brains of aging adults,” said the lead researcher. These findings have important clinical implications for developing early screening programs for hearing loss in adults. To read more about this study, click here.