Figure 4.

AN responses correctly predict perceptual attributes of consonance, dissonance, and the hierarchical ordering of musical pitch for normal hearing. Neural pitch salience is shown as a function of the number of semitones separating the interval’s lower and higher pitch over the span of an octave (i.e., 12 semitones). The pitch classes recognized by the equal tempered Western music system (i.e., the 12 semitones of the chromatic scale) are demarcated by the dotted lines and labeled along the curve. Consonant musical intervals (black) tend to fall on or near peaks in neural pitch salience whereas dissonant intervals (gray) tend to fall within trough regions, indicating more robust encoding for the former. However, even among intervals common to a single class (e.g., all consonant intervals), AN responses show differential encoding resulting in the hierarchical arrangement of pitch typically described by Western music theory (i.e., Un > Oct > P5, > P4, etc.). All values are normalized to the maximum of the curve which was the unison.