Speaking from Two Sides of the Mouth

Abstract

Differences while speaking from the two sides of the mouth are both visible and audible. Careful observation has shown that the right side of the mouth typically opens wider and moves more during speech.This visible asymmetry reveals the underlying physiology in which expression of speech is controlled primarily by the left side of the brain. Since the left side of the brain has better control of the right side mouth muscles, an asymmetry favoring the activity of the muscles of the right side results during articulation of speech sounds. In contrast, more equal activity from the left side of the mouth can be seen during emotional expression, prosodic expression, and singing which reveals a greater role of the right side of the brain during these latter types of expression. There are also audible manifestations of the physiological asymmetries. In a new study, subjects were required to speak from only one side of the mouth. Better quality of articulation was audible from the right side for most subjects.