An error correction scheme for GCI detection algorithms using pitch smoothness criterion

Abstract

Detection of error-free glottal closure instants (GCI) is a critical requirement for many applications including text-to-speech synthesis, causal anti-causal decomposition and voice morphing. Many existing GCI detection algorithms commit errors under certain conditions. In this paper, we propose a post processing scheme for correcting errors of any GCI detection algorithm. The proposed error correction scheme works on the principle that the fundamental frequency over a voiced segment is slowly varying. The error correction is thus formulated as an optimization problem such that the pitch contour from the corrected GCIs has the least high frequency components. The proposed error correction scheme is experimentally evaluated on speech corpus with simultaneous EGG recordings using three state-of-the-art GCI detection algorithms viz., Dynamic Plosion Index (DPI), Zero Frequency Resonator (ZFR), and Speech Event Detection using the Residual Excitation And a Mean-based Signal (SEDREAMS). It is found that the proposed error correction scheme improves the performance of the GCI detection in clean speech as well as noisy conditions at different SNRs.