Our Expectations Of Sound May Influence What We Hear, Study Shows

Researchers are looking to determine what shapes how we hear sound. According to scientists at Bournemouth University, the expectation of what we're about to hear may instantaneously shape how our sound is processed. 

"Almost 80% of connections between central and pre-cortical areas during sound processing seem to be top-down i.e. from the brain to the auditory peripheral system and not bottom-up, which is perhaps unexpected," he explains. "As sound comes from an external stimulus, it would be fair to assume that most of our processing occurs from what we hear, but that is apparently not the case. What your brain expects to hear can be as important as the sound itself."

The researchers were able to combine magneto and electroencephalography to map brain activity through recording electromagnetic currents that occur naturally in the brain and in the brainstem simultaneously. This helps allow for very detailed temporal information on how the brain processes sound to be recorded, allowing for researchers to develop models in detail of how the brain processes sound.

Dr. Balaguer-Ballester added that this work could potentially lead to the treatment of certain auditory processing disorders.

"This could be the first step towards a better understanding of auditory central processing disorders in children. If their learning difficulties stem from the way their brain processes sound and not in their peripheral auditory system, this requires very different treatment to a child who develops serious hearing loss after an illness. Central processing disorders can lead to problems such as the delay of language development in children, so it is important to be able to pinpoint the neural parameter which is altered, in order to appropriately treat the cause of such an alteration."

"For postgraduate students and PhD students, this is really important," he concluded, "as they are able to see their articles published without delay which helps their careers. It also meant that research is freely available to use by a much wider audience."