An ultrasound demonstration of tongue anatomy and speech activity

Abstract

Soft tissue detail, motion display, and subject safety are features of ultrasound imaging that make it ideal for viewing the tongue and floor of the mouth during speech. In addition to the tongue surface, much of the intrinsic anatomy can be identified including the genioglossus, geniohyoid, mylohyoid, and digastric muscles; fascial boundaries such as the median fibrous septum of the tongue, the floor of the mouth intermuscular septum, and paramedian septums; and the hyoid bone. This study correlates the clinical ultrasound image with the anatomy demonstrated by tongue dissection. In addition, tongue movement during production of the speech sounds /ɑ/, /i/, and /k/ was examined in ten normal speakers and three patients with dysarthria. Tongue movement was found to be consistent for the normal speakers of /i/ and /k/. The three patients with neurological disease showed varying but significant differences in articulation compared to normals including prolonged movement, decreased intrinsic tongue activity, and a tendency to move the tongue as a unit with increased utilization of the floor of the mouth muscles. It appears that real-time ultrasound imaging of the oral cavity is a potentially valuable technique for the investigation of normal and abnormal speech.