Air movements that occur in addition to breathing are called non-respiratory movements. They are used to clear air passages, as in coughing or sneezing, or to express emotions, as in laughing or crying. Also included in this category are hiccupping and yawning, as well as speech, where air is forced through the larynx, causing the vocal cords to vibrate. In speech, words are formed by lips, the tongue, and the soft palate.