Automated vowel space measurement of young children

Abstract

Vowel formant frequencies are frequently reported as a measure of the articulatory workspace and have been used to study speech development and speech disorders across the lifespan. It is widely acknowledged that the measurement of F1/F2 frequencies for Vowel Space Area (VSA) estimation is a cumbersome task, wrought with challenges and uncertainties. Although there have been advancements in automated approaches, many of these tools continue to be challenged by child speech due to the anatomical differences and dynamic changes of the supraglottal, glottal, and subglottal regions of the airway during the years of speech development. This study examines automated VSA estimation in 4-year-old children using models that have been adapted to manage the higher fundamental frequencies, wider formant bandwidths, and higher amplitudes of subglottal resonances detected in child speech. The speech of six, native American English-speaking, four-year-old children with no history of hearing or speech disorders were included in this investigation. 48 words, including eight American English vowels, were analyzed using traditional manual methods and the SpeechMark MATLAB toolbox automated VSA estimator. The toolbox automates the generation of a convex hull enclosing the child VSA and computation of the area while accounting for the anatomical/acoustic differences that occur during early speech development.