Which of the following structures does NOT contribute to the functioning of the larynx?

The diaphragm is primarily a muscle that plays a critical role in respiration. It is located below the lungs and is involved in the process of inhaling and exhaling by changing the volume of the thoracic cavity. While it indirectly supports laryngeal function by facilitating breath control necessary for phonation, it does not contribute directly to the larynx's structure or its precise functioning in sound production.

In contrast, the intrinsic laryngeal muscles directly manipulate the vocal folds to produce sound. They control the tension and position of the vocal cords, playing a crucial role in voice pitch and quality. The extrinsic laryngeal muscles, which anchor the larynx and help adjust its position during respiration and phonation, also significantly influence laryngeal function. The cartilages of the larynx provide structural support and form the framework necessary for the larynx's operation. Thus, while all the other structures listed are integral to laryngeal functioning, the diaphragm does not contribute directly, making it the correct answer.