Cascaded all-pass filters with randomized center frequencies and phase polarity for acoustic and speech measurement and data augmentation

Abstract

We introduce a new member of TSP (Time Stretched Pulse) for acoustic and speech measurement infrastructure, based on a simple all-pass filter and systematic randomization. This new infrastructure fundamentally upgrades our previous measurement procedure, which enables simultaneous measurement of multiple attributes, including non-linear ones without requiring extra filtering nor postprocessing. Our new proposal establishes a theoretically solid, flexible, and extensible foundation in acoustic measurement. Moreover, it is general enough to provide versatile research tools for other fields, such as biological signal analysis. We illustrate using acoustic measurements and data augmentation as representative examples among various prospective applications. We open-sourced MAT-LAB implementation. It consists of an interactive and real-time acoustic tool, MATLAB functions, and supporting materials.

Mixture of orthogonal sequences made from extended time-stretched pulses enables measurement of involuntary voice fundamental frequency response to pitch perturbation

“…We succeeded in making test signals which are unpredictable and do not have MLS's difficulty. Our new system analysis method uses a new extended TSP called CAPRICEP (Cascaded All-Pass filters with RandomIzed CEnter frequencies and Phase Polarities) [6]. We used CAPRICEP and developed an auditoryto-speech chain analysis system by adopting the simultaneous measurement method of linear, non-linear, and random responses [5].…”

“…Test signal design consists of the following four steps. The first step generates extended TSP signals (unit-TSPs) based CAPRI-CEP [6]. The "CAPRICEP generator" in Fig.…”

“…We designed the temporal distribution of the power of unit-TSP to have the raised cosine shape [6]. The nominal duration of the unit-TSP was 400 ms. We set the allocation interval of unit-TSPs as 16384 samples (371.5 ms for 44100Hz sampling).…”

“…The fundamental frequency (fo) 1 of sustained vowels respond to frequency modulation of aurally presented sounds [2][3][4]. This response, combined with our recently developed system analysis method [5,6] provides a versatile new tool for investigating the auditory-to-speech chain. Preliminary tests illustrated that the proposed method provides accurate measurement of the involuntary response to fo perturbation of the aurally presented test signals.…”