Bilateral neural packets are the basic mechanism of sensation and of thought. Bilateral neural packets essentially form from sensory input and those mimes then persist in what we call thought, which is a neural packet for a given moment of thought. Each organ of sensation like the ear will have unique mimes with similar characteristics to other organs and the human ear will sense sound in ways that are similar to how the eye processes light.
Although there are many components within the human ear, the basic neural organ of hearing is the cochlea. The cochlea has a spiral shape (see Figure) and with both impulse and response fluid canals with the very well known frequency response shown in the figure. Tiny hairs along the length of the basilar membrane, which is the wall between to the spiral cochlea impulse and response canals, are the neurons that sense sound by the inner ear fluid deflection of a tiny hair. The neural patterns in the EEG that come from basilar excitation are many and varied, but the hearing neural network is still not well understood. In fact, science does not seem to have a very clear understanding of the underlying neural impulse patterns for even simple organisms.
The 7 notes of the octave are very suggestive, though, of a binary or bilateral difference sampling between groups of selected neurons and the top three rows of Pascal's triangle of the binomial theory describe how this binary sampling adds up to 7. This implies that the same kind of bilateralism that we recognize as the left-right symmetry is a part of hearing. Indeed, bilateralism is very common in all higher organisms and indeed also in the binary frequency analysis of sound and other spectral data with the Cooley-Tukey fast Fourier transform (FT) algorithm. The basic FT algorithm processes spectral data by sampling a time series with powers of two averaging and bilateralism is therefore an efficient way to sample and compress time series data into frequency amplitudes for representation in thought packets.
Therefore it seems very reasonable that along the basilar membrane, neurons from 20 mm to the end would be progressively paired into 7-mer's with the midpoint defined by middle C at 262 Hz, which peaks at 27 mm from the stapes. These progressive bilateral neural pairings would then form difference modes that would complement the sum and total modes and enhance sensation of the frequencies lower than ~1000 Hz as shown. These 7-order difference pairings would then effectively provide for our pleasure hearing the tones and chords of music.