DysarthriaMotor speech disorders: Motor speech disorders are a class of speech disorder that disturb the body's natural ability to speak. These disturbances vary in their etiology based on the integrity and integration of cognitive, neuromuscular, and musculoskeletal activities.Fragile X-associated tremor/ataxia syndrome: Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late onset neurodegenerative disorder associated with problems of movement, memory, and the autonomic nervous system. It is related to the disease fragile X syndrome, although FXTAS is a clinically distinct syndrome.Diadochokinesia: Diadochokinesia or diadochokinesis is the ability to make antagonistic movements in quick succession, alternately bringing a limb into opposite positions, as of flexion and extension or of pronation and supination. Speech-language pathology defines it as the speed necessary to stop a determined motor impulse and substitute it with its opposite.Elective mutism: Elective mutism is the former name for selective mutism. Elective mutism was defined as a refusal to speak in almost all social situations (despite normal ability to do so), while selective mutism is considered to be a failure to speak in specific situations and is strongly associated with social anxiety disorder.Front vowel: A front vowel is any in a class of vowel sound used in some spoken languages. The defining characteristic of a front vowel is that the tongue is positioned as far in front as possible in the mouth without creating a constriction that would make it a consonant.Autosomal recessive cerebellar ataxia: Autosomal recessive cerebellar ataxia type 1 (ARCA1) is a condition characterized by progressive problems with movement. Signs and symptoms of the disorder first appear in early to mid-adulthood.Dysprosody: Dysprosody, which may manifest as pseudo-foreign accent syndrome, refers to a disorder in which one or more of the prosodic functions are either compromised or eliminated completely.Key word signing: Key word signing is a technique of Simultaneous Communication whereby the communication partner of the user will use both natural speech and also produce signs for the words that carry the most important information.Windsor, J.HyperintensitySilent speech interface: Silent speech interface is a device that allows speech communication without using the sound made when people vocalize their speech sounds. As such it is a type of electronic lip reading.