The document discusses the larynx, which is located in the neck and made of cartilage. It plays a role in both respiration and voicing speech sounds. The larynx can vary the intensity, frequency, and quality of voicing through actions like phonation. Different types of plosive consonant sounds are distinguished by where the airflow is obstructed in the vocal tract, such as with the lips, tongue against the alveolar ridge, or tongue against the soft palate. The document also mentions fortis and lenis sounds as well as stammering.