In articulatory phonetics, we investigate how speech sounds are produced using the fairly complex oral equipment we have. We start with the air pushed out by the lungs up through the trachea (or windpipe) to the larynx. Inside the larynx are your vocal folds (or vocal cords), which take two basic positions.
When the vocal folds are spread apart, the air from the lungs passes between them unimpeded. Sounds produced in this way are described as voiceless. 2 When the vocal folds are drawn together, the air from the lungs repeatedly pushes them apart a sit passes through, creating a vibration effect. Sounds produced in this way are described as voiced.