Vsameter: Evaluation of a New Open-Source Tool to Measure Vowel Space Area and Related Metrics

Vowel space area (VSA) is an applicable metric for studying speech production deficits and intelligibility. Previous works suggest that the VSA accounts for almost 50% of the intelligibility variance, being an essential component of global intelligibility estimates. However, almost no study publishes a tool to estimate VSA automatically with publicly available codes. In this paper, we propose an open-source tool called VSAmeter to measure VSA and vowel articulation index (VAI) automatically and validate it with the VSA and VAI obtained from a dataset in which the formants and phone segments have been annotated manually. The results show that VSA and VAI values obtained by our proposed method strongly correlate with those generated by manually extracted F1 and F2 and alignments. Such a method can be utilized in speech applications, e.g., the automatic measurement of VAI for the evaluation of speakers with dysarthria.