Estimation of minimum oral tract constriction area in sibilant fricatives from aerodynamic data.

Speech screening of sibilant fricative phonemes is an important tool for oral health care. Nevertheless, screening as a function of quantitative geometrical markers is mostly limited to teeth features whereas the minimum area of the narrowed air passage upstream from the tooth is known to be a key production feature. The minimum area is estimated from non-invasive aerodynamic measurements using a laminar flow model. The influence of viscid flow losses on the area estimation is shown to be negligible. Current data suggest that speech screening is most effective for phoneme /s/, which supports common practice in oral health care.