The challenges and uncertainties when hand measuring F1/F2 values in child speech: Towards an automated approach

Abstract

Vowels serve a critical role in understanding the acoustic properties of speech. Since they appear early in speech development, they can be used to assess important speech milestones. Prior literature provides the empirical foundation for understanding expected F1/F2 values for typically developing children. Although the traditional measurement of the first and second formant frequencies is a widely accepted practice, its clinical use is limited because of the challenges and uncertainties that are encountered during the process. Automated tools have been developed to address these limitations, however many of these tools have been reported to have inconsistencies when identifying F1/F2 values for child speech. This study explores the use of three semi-automated measurement methods: Wavesurfer Linear Predictive Coding, Praat formant tracking, and a lab-developed approach. The speech of six, native English-speaking, four-year-old children with no history of hearing or speech disorders was analyzed. 48 words, including eight American English vowels, were measured using the three approaches by two researchers, an undergraduate researcher, and an experienced research mentor. The challenges, procedural observations, and accuracy of the methods are discussed. This project was supported by the SURIEA summer research internship program.