Christopher X J. Jensen
Associate Professor, Pratt Institute

What deficiencies in sound perception reveal about how we perceive sound

Posted 03 Dec 2015 / 0

Only HumanYour Brain on Sound

This is a great feature that uses the experience of a particular person (“Rose”) to explain how important the brain’s filtering of sound stimuli is to our perception of sound. Rose suffers from auditory neuropathy, which prevents her brain from responding to sound with neural synchrony. This makes it really difficult for her to interpret language, particularly when that language is inter-spersed with other sounds. Essentially, Rose is “deaf in noise”.

Rose’s case — like a lot of other neurological disorders — helps shed light on how our brains have evolved to function normally. While our ears simply convert sound into neurological signals, our brains actually filter that signal so that we can pick out sounds that are important from background noise. This is a particularly important function for discerning the subtleties of language, where intonation conveys a lot of meaning on top of the basic phonic pattern of our words.

It is fascinating that our brains basically applify patterns through neural synchrony to allow us to better perceive sound. It is almost as if we have built-in spectral filtering. Those who lack this filtering can’t interpret sound adequately, which proves to be a major disability.

I was also fascinated by the idea that our brains produce activity that is analogous to the sounds we hear. This analogy is so profound that brain-wave activity patterns can be “played” back to identify the sound that was originally perceived by the brain. While the fidelity of these “recordings” is low, it is amazing that the neurolgical analogy of what we hear is so strong that brainwaves make for understandable sound waves.

A Minor Post, Minor in Sound & Music Studies, MSCI-363, Biological Origins of Sound & Music, Radio & Podcasts, Sound Perception

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