Binaural Spectral Complexity Reduction of Music Signals for Cochlear Implant Listeners

Abstract

An emphasis on the leading voice or melody is known to facilitate music perception in cochlear implant (CI) listeners while a competing accompaniment is perceived as disturbing. In this paper we present the extension of a monaural music complexity reduction scheme for CI users towards a binaural application. The scheme aims at an attenuation of the accompaniment in music signals and relies on a reduced-rank approximation by means of principal component analysis (PCA). In the proposed binaural system the PCA is only performed for the melody dominated ear and its eigenvectors are used for a reduced-rank representation of both ear signals. We use SIR and SAR measures for evaluation and show that with binaural processing a further attenuation of the accompaniment can be achieved in comparison to separate bilateral processing of both ear signals. At the same time neither additional artifacts are introduced to the reconstructed melody signals nor the binaural cues accessible to CI users are considerably harmed.