Filtering on non-linear time axis and its application for measuring perception to production transfer functions in F0 control

摘要

Auditory feedback effects in F0 control has been investigated. It was reported that there are two systems, one is a fast system with a characteristic frequency 6 Hz and the other is a slow system with a characteristic frequency 0.3 Hz, working together. A non stationary filtering was implemented using a combination of nonlinear transformation of the time axis and its inverse transform with low-pass filtering to extract a reliable portion of a time-frequency representation to investigate these interactions. Combination of the proposed non stationary filtering with M-sequence based stimulation effectively suppresses spurious responses due to nonlinearity in F0 control. A set of simulations and preliminary tests using real speech examples illustrated that the proposed method enables reliable estimation of the perception to production transfer function of F0 in voicing.