Estimating the location and degree of constriction and labial aperture in emphatics in Jordanian Arabic

Abstract Arabic dialects are often anecdotally described as existing on a continuum of guttural quality, driven by varying degrees of pharyngeal constriction. To empirically assess this, we collected phonetic data from two Jordanian dialects: rural and urban. We employ acoustic analysis and various metrics to quantify the upper and lower vocal tracts’ contribution to the production of emphatic sounds. Our analysis specifically aims to estimate the degree and location of articulatory constriction of emphatics in these dialects, and to identify the role of lip aperture in their production. We analyze vowel formants using generalized additive mixed models. Subsequently, we perform an articulatory estimation using the first two formants and their amplitudes to describe the labial posture and overall vocal tract configuration in emphatics. Our findings reveal that the rural dialect exhibits a more pronounced guttural quality, characterized by laryngopharyngeal constriction. In contrast, the urban dialect primarily shows upper pharyngeal (dorsal) constriction. Furthermore, the study reveals a causal relationship between lip protrusion and the degree and location of articulatory constriction of emphatics within the vocal tract.