Synthesis of Bowhead Whale Sound Using Modified Spectral Modeling

Abstract

Spectral modeling synthesis (SMS) considers a sound as a combination of a deterministic plus a stochastic component that makes possible for a synthesized sound to attain all the perceptual characteristics of the original sound. However, sometimes considerable phase variations occur in the deterministic component by using SMS since the addition of different frequency sinusoids in the overlap region causes amplitude distortion. As a result, subtraction between original and deterministic signal in time domain do not provide a good approximation of the residual signal. To overcome this problem, we propose a modified SMS that provides good approximation of the residual signal by calculating the complex residual spectrum in frequency domain. Analysis and simulation results for synthesizing bowhead whale sounds suggest that the proposed method is comparable to the SMS in both time and frequency domain. However, the proposed method outperforms the SMS in better spectrum matching because of the use of original phase information to synthesize the deterministic component as well as good approximation of the residual signal by subtracting the deterministic spectrum from the original spectrum and then utilizing spectral fitting.