What generates pressure during speech expiration?

• A. Increased diaphragmatic pressure
• B. External intercostals contraction
• C. Contraction of expiratory muscles
• D. Increased lung volume

Answer: (C)

Contraction of expiratory muscles is the correct answer as it plays a crucial role in generating pressure during speech expiration. The act of speaking requires a controlled expulsion of air from the lungs, which is facilitated by the contraction of various expiratory muscles, including the abdominal muscles and internal intercostals. When these muscles contract, they decrease the volume of the thoracic cavity, leading to an increase in pressure within the lungs. This pressure difference is essential for driving air out of the lungs and facilitating voice production.

The other options relate to aspects of respiration but do not specifically focus on pressure generation during speech. Increased diaphragmatic pressure pertains to inhalation rather than the controlled exhalation required for speech. The contraction of external intercostals primarily aids in inhalation by elevating the rib cage. Increased lung volume typically occurs during inhalation as the diaphragm contracts and the thoracic cavity expands, rather than during the act of expiration itself, particularly in the context of generating speech.