Are sound sources of voiceless glottal fricative [h] generated at the glottis?

Abstract

In this study, we investigate the sound source location of the voiceless glottal fricative [h] using aeroacoustic simulations based on 3D vocal tract geometries extracted from MRI. The vocal tract geometry of [h] in /ha/ and /ho/ produced by a Japanese male were analyzed with two glottal configurations: an adducted and a resting state. By solving the compressible Navier-Stokes equations, the airflow and sound generation were simultaneously simulated. Results revealed that primary sound sources appeared from the upper pharynx to the soft palate in /ha/, whereas sound levels decreased by over 20 dB when the glottis opened in /ho/, indicating the glottis is the main sound source in /ho/.