When we talk, we make sounds with our voice box, also called the larynx. We use different parts of our mouth to change the sounds we make. One of these parts is called the glottis, which is a space between our vocal cords. When we say some words, we stop the air from flowing out of our mouth by closing this space in our throat. This closing of the glottis is called a glottal stop. It's like a little hiccup sound in the middle of a word. You can try it yourself by saying the word "uh-oh" – the little sound you make before the "oh" is a glottal stop. Some languages, like Hawaiian and Arabic, use glottal stops in their everyday speech.