AMC-SS: Dynamic Algorithms For Blind Separation Of Convolutive Sound Mixtures

University Of California-Irvine, Irvine CA

Investigators

Abstract

The principal investigator and coworkers will study mathematical and computational issues of blind source separation algorithms of convolutive sound mixtures. The convolutive sound mixtures appear in any enclosed environment when there are multiple speakers. The goal is achieve dynamic separation of mixtures and source recovery adaptively with no prior knowledge of the environment, based on source independence and received data at multiple locations. Though the fast Fourier transform helps to localize the problem in the frequency domain, and separation is quite successful at each frequency with existing methods, permutation and scaling issues remain indeterminate and may greatly influence the separation quality. The investigators will use dynamically updated statistical signal information to fix permutation, and minimization of mixing filter lengths in the time domain to fix scaling. They will also study dynamic algorithms in the time domain by optimizing mixing filter lengths and source independence, as well as the dynamic stability and convergence of the recovered mixing filters by using probability theory. The project aims to develop algorithms to separate realistic sound mixtures, a task that machines (computers) are unable to perform as well as humans. The challenge, also known as the cocktail party problem, is fundamental to improving the quality of modern hearing devices. For example, hearing aids and cochlear implants are known to work well in quiet, however, they degrade rapidly when there are competing sound sources. Even for normal hearing people, it is difficult to carry out a conversation over a cell phone call that comes from a rather noisy location such as a restaurant. Understanding the mathematics of blind source separation and applying it to actual computation is a key step to solution. The project bodes well in generating broad impact and making mathematical contributions to the advancement of information technology and biotechnology.