Objective measurement of pitch extractors' responses to frequency modulated sounds and two reference pitch extraction methods for analyzing voice pitch responses to auditory stimulation

TL;DR

This paper introduces an objective method for evaluating pitch extractors' responses to frequency-modulated sounds, revealing limitations of existing extractors and proposing two new reference methods for accurate analysis of voice pitch responses to auditory stimuli.

Contribution

It presents a novel measurement approach for pitch extractor responses, identifies shortcomings of current methods, and offers two new reference extractors with open-source MATLAB code.

Findings

Existing pitch extractors fail on signals used for auditory stimulation.

Two new reference pitch extractors accurately analyze test signals.

Open-source MATLAB tools are provided for evaluation and experiments.

Abstract

We propose an objective measurement method for pitch extractors' responses to frequency-modulated signals. The method simultaneously measures the linear and the non-linear time-invariant responses and random and time-varying responses. It uses extended time-stretched pulses combined by binary orthogonal sequences. Our recent finding of involuntary voice pitch response to auditory stimulation while voicing motivated this proposal. The involuntary voice pitch response provides means to investigate voice chain subsystems individually and objectively. This response analysis requires reliable and precise pitch extraction. We found that existing pitch extractors failed to correctly analyze signals used for auditory stimulation by using the proposed method. Therefore, we propose two reference pitch extractors based on the instantaneous frequency analysis and multi-resolution power spectrum analysis. The proposed extractors correctly analyze the test signals. We open-sourced MATLAB codes to measure pitch extractors and codes for conducting the voice pitch response experiment on our GitHub repository.