Which factor influences Maximum Phonation Time (MPT)?

• A. The color of the vocal fold tissue.
• B. The patient's lung capacity, age, sex, size, and health.
• C. The average airflow rate during phonation.
• D. The subglottal pressure range.

Answer: (B)

Sustaining phonation on one breath depends on how much air you have available and how efficiently you can use it. Maximum Phonation Time reflects the respiratory support behind the voice, so the factor that best influences it is the person’s lung capacity, along with how age, sex, body size, and overall health shape that capacity. A larger lung capacity means more air to push through the vocal folds for a longer period, while age, sex, size, and health determine typical lung volumes and how well the respiratory system can supply and control that air.

The color of the vocal fold tissue doesn’t affect how long you can sustain phonation. The average airflow rate during phonation describes how quickly air leaves, not how long it can be sustained. Subglottal pressure range matters for voice quality and ease of phonation, but the fundamental limit on duration is the amount of air you can breath in and efficiently use.