Analysis and synthesis of amplitude modulation components in pathological voices

Previous work addressed analysis and synthesis of the FM and aspiration noise components of pathological voices. The current study refines the previous analysis and adds amplitude modulation to model non-periodic components. The cepstral aspiration noise estimate is improved by removal of HFPV (high frequency pitch variation) from the original voice prior to estimating the noise. Amplitude and pitch pulse power tracking are performed on a pulse-by-pulse basis to accurately estimate the power time series, which is then segregated into low frequency power variation and high frequency power variation (shimmer). These AM effects are then also removed from the original voice and cepstral noise analysis is applied to estimate aspiration noise. Results show that incorporation of the AM effects improves the fidelity of the synthesized voice, and that AM has a minimal effect on the measured level of aspiration noise.