Music Appreciation and the Auditory System :: Biology Essays Research Papers

Music Appreciation and the Auditory System Have you ever come home after an exhausting day and turned on music to relax your nerves? While you are taking it easy, your auditory cortex is not. It works hard to synthesize the several musical elements of rhythm, pitch, frequency, and timbre to create a rich auditory experience. First, a discussion of the ear physiology is needed. Vibrating air moving at different frequencies hits the eardrum which causes the middle ear's three bones to move accordingly. The stapes, one of these inner ear bones hits on the oval window of the inner ear, and because the inner ear is filled with fluid, the bulging of the oval window causes this fluid to slosh around. The round window, also in the inner ear, compensates for the increased pressure by bulging outward. The inner ear has two functions, to transduce sound via the cochlea and to maintain a person's vertical position with respect to gravity via the vestibular system (1). . But here, we will only consider the transduction of sound. The cochlea is filled with hair cells that are extremely sensitive and depolarize with only slight perturbations of the inner ear fluid. At the point of depolarization, a neural signal is transmitted and on its way to the brain. This nerve impulse travels to the auditory nerve (8th cranial ne rve), passes through the brainstem, and then reaches the branched path of the cochlear nucleus: the ventral cochlear nucleus or the dorsal cochlear nucleus. The nerve signal that passes through the ventral cochlear nucleus will reach the superior olive in the medulla where differences in timing and loudness of sound are compared, and location of the sound's origin is pinpointed (1). The nerve signal that crosses the dorsal cochlear nucleus ultimately is analyzed for sound quality. As seen in the final step of sound transduction, the information relayed by the neural signal branches and processing occurs at different sights. No consensus has been reached as to where music is processed in the brain. Most researchers agree that the different components of music are processed in different parts of the brain, as exemplified by the branching pathway of the cochlear nucleus which facilitates the separation of sound timing and loudness with the sound quality analysis. But this information is not sufficient to answer the question of where our sense of music originates. Frackwiak has supplied a small part of the puzzle.