Resting larynx. Image 1 of 2. Endoscope view of a healthy larynx (voice box) showing resting vocal cords (v-shaped, centre left and right). The vocal cords are responsible for the production of sound. In the resting position seen here they lie either side of an opening (centre) known as the glottis. When brought close together they vibrate and emit sounds as air expelled from the lungs passes through them. Altering the tension in the cords produces sounds of different pitch. These are modified by the tongue, palate and lips to produce speech. For a view of the larynx in the closed position, see image P496/013.