VSpace: A browser-based vowel synthesiser

Abstract

Two-formant representation of the universal vowel space is a foundational model in phonetics (Fant & Risberg 1963; Traunmüller & Lacerda 1983), but tools for rapid synthesis of vowel sounds corresponding to points in the vowel space are limited. Stand-alone applications such as the Formant Synthesizer Demo (Beskow, 2000) provide this functionality, and rich tools for formant synthesis are available in Praat (Boersma and Weenink, 2023), Matlab (Rabiner et al., 2023) and other platforms, but these tools are not universally accessible, while web-based speech synthesis tools (e.g., Thapen, 2017) do not typically allow systematic manipulation or quantification of key acoustic parameters. VSpace is a browser-based formant synthesizer developed using the Tone.js Web Audio framework. A universal vowel space is represented as a trapezoid scaled to typical male, female or child speaker formant ranges. Clicking on any point generates a vowel sound corresponding to the first and second formant frequencies selected, synthesized with typical F3 and F4 frequencies excited by a selectable source signal. IPA symbols corresponding to typical formant frequencies for language-specific vowel phonemes may be superimposed on the vowel space. Key synthesis parameters are configurable through the web interface to allow exploration of the acoustic consequences for vowel perception.