How does your brain process sound envelopes?
A team of scientists created sounds with different harmonic and amplitude footprints. The pumped these sound through a pair of Koss headphones while their subjects lay on the Magnetic Resonance Imagining (MRI) machine. What they found may suprprise you.
They found noise and harmonic sounds activate different slightly different parts of the brain. There are various parts of the brain that process “music” and other parts process “sound.” Many composers would argue where those lines should be drawn. (If even at all) But the research subjects clearly showed that different parts of the brain are used for specific types of sounds.
But if sounds that switched between harmonic and noise sources activate the most sections of the brain. So, is this best path for interesting music? Should musicians find a way to balance harmonic and in-harmonic noises in order to trigger the largest synaptic response?
My question for the researchers (if they are self googlers) – how much variation was their between each subject? Does everybody use the same of part their brain to process these sounds?
Full Paper Link: Analysis of the spectral envelope of sounds by the human brain
Authors: J.D. Warren, A.R. Jennings and T.D. Griffiths
Shape Changing Instruments 
risking to be one of these people not that willing to draw such lines, I think this raises interesting questions: the unpitched content of so called musical sounds is substancial, (points of articulations, attacks, the means by which discontinuity is expressed and perceived are full of it in the form of transients) , and so called noise, even the result of chaotic systems, like running water for example, is full of pitch! Could it be more that the knowledge of something being “music” has certain learnt associations whilst “noise” has others,By the way, If I hear an escalator, or my central heating boiler with a relaxed ear, I hear a hell of a lot of rich layered pitch content. My central heating boiler does tend to be a bit boring and samey though, as though it might go on forever…where would it be played in the experiment? noise or harmonic?
Yes! I think there is something about being able to describe a pressure wave of air that is very much learned. As one becomes aware of different sound sources, and develops a vocabulary to describe them, I bet more sounds of the brain are active. But if this study is to be redone, I wonder what metric would be best to classify the “listeners.” Musician/nonmusician? Age? Geographical location? Culture? Language?
Oops — the link to the paper has disappeared. There seems to be a lot left to understand about how we perceive music. This is a big deal for cochlear implant users. Progress is being made, but there is a world o progress yet to make. Please let me know if you hear of anything new.