The Ear and the Brain: Sensation and Perception
March 1, 2017
Originally published on Facebook on 2.13.16
What does the brain do to the sensations produced by sound waves. Pitch versus repetitive loudness. Tone quality versus a combination of pitch and loudness. Shape versus notes. Shape versus structure.
Today’s entry remains philosophical. I promise to get back to the more musical and technical aspects of playing piano, tomorrow.
1. The “ear” (the brain) chooses to suppress the information about repeated louder attacks of sound, happening over and over again, from 15 to thousands of times per second, and creates instead a different modality of perceiving this inconstant sense data as a ‘constant’ “pitch”. Whether this suppression was done to ‘simplify’ the sense data, which else would be too complicated to be conscious of it in all its parts, or for some other reason, we do not know.
2. The “ear” (the brain) chooses to suppress the information about the variety of pitches bundled in the “single” sound, and creates instead a different modality of perceiving this variety of sense data, namely “timbre” (tone quality, instrumental color). Whether this suppression was done to ‘simplify’ the sense data, which else would be too complicated to be conscious of it in all its parts, or for some other reason, we do not know.
3. We now carry this out to a very abstract concept in making music: “shaping a phrase”. To shape a phrase, a performer plays a series of notes with a loudnesses that are nearly the same, but from one note to another. slightly different. If the differences are too big, the listener hears a change in ‘loudness’ (crescendo or decresendo). But if the differences are small enough, the brain ceases making us aware of these changes in loudness, and replaces it instead with a new modality: the “shape” of a series of notes. Albeit a more ‘abstract’ characteristic, but one formed from simpler components as an emergent form.
In no. 1, sense data that is altering many times per second in time, is recast as something that remains the same in time. Difference becomes sameness, so that the latter, the pitches, can be used in even larger constructs (phrases, melodies, movements, pieces), which in turn exhibit variability through (longer periods of) time.
In no. 2, the simplification of hearing timbre (a clarinet, a violin, a voice), which is more at being constant through time, replaces the difficulty of having to perceive simultaneously in time, 10 to 25 different pitches all at once, and having to perceive the same again as soon as we hear the next note, and then the next, etc.. These pitch differences are “summarized” in the brain by transcending the identity of the pitches, and instead the structurally larger notion of the relative loudnesses among the pitches,
then creating a new modality “sound-quality” that varies at a slower rate through time.
From no 1 to no 2 we see data which is over complicated versus time units, changed to something which in contrast is more settled and stable in time. From 2 to 3, we take the results of going from no. 1 to no. 2 (from loudness to pitch), and taking information about simultaneous pitches in a brief amount of time, and changes it to something which,, again, in contrast is more settled and stable in time (tone-qiality).
4. We note so far a tendency to go from briefer units of time to longer units. What then can we do if we wish to take pitch and tone color, already relatively more stable in time, and create a perceptual modality that is even more unchanging with time. The answer is that the vicissitudes brought about by ongoing time are almost ‘conceptually’ transmuted into the figurative pseudo-presence of a “shape”. The term shape is borrowed from space, and to the degree we perceive it in what we hear, it is almost on the verge of being a metaphor, but nonetheless relies on the synthetic ability of the brain to make more complicated by simplifying.
5. Describing long-term changes in time is challenging for language, and usually devolves into borrowing metaphors from space. I would think that the ultimately ‘long’ unit in hearing is “structure”, or the shape of an entire movement or longer piece of music. That the greatest composers could create structures in time alone is undoubted. What is difficult is training a musician to hear and respond to something whose sub-units vary over long periods of time: too slow to “hear” and yet immanent in the sound.