Gravitational Search Algorithm for IIR Filter-Based Audio Equalization

In this paper we present an evolutionary algorithm for the design of stable IIR filters for binaural audio equalization. The filters are arranged as a cascade of second-order sections (SOS’s) and the gravitational search algorithm (GSA) is used. This process seeks for optimal coefficients based on a fitness function, possibly leading to unstable filters. To avoid this, we propose two alternative methods. Experiments have been performed taking an in-car listening environment as the use case, characterized by multiple loudspeakers, thus, multiple impulse responses (IR). This technique has been compared with a previous heuristic method, achieving superior results.