Study on the Relationship between Melody Perception and Music Harmonics

Melody is the key perception of music. For the heavy sensory nerve deafness, the current cochlear implant (CI) user has the clinical effect on speech recognition, but the music melody and timbre perception is not acceptable, they could not normally perceive music information. Based on CI encoding principle of multi-channel filtering and music harmonics analysis and synthesis technology, this paper studies the relationship between melody perception and harmonic structure of music signal. Utilizing Fourier transform, the original music signal spectral were analyzed, the selected harmonic components were filtered and then rebuilt the synthesized sounds by Fourier inversion transform. Several single music note and melody segments audiometry tests were experimented by normal hearings. The test results show that the fundamental frequency was the decisive component of pitch perception, lacking other few harmonics affected pitch perception much slightly, but large numbers of harmonic absence deteriorated music quality and consequently affected pitch perception, even the fundamental wave still remained, which might relate to the destruction of spectral structure. So it is concluded that music melody perception is related to the signal channels of multi-channel CI or electrodes distribution, good music perception should based on reasonable electrodes distribution. The study results suggested that the electrodes distribution should be optimized and electrode number should be increased properly in cochlea locations corresponding to the characteristic frequency of music basic notes.