Which of the following factors is NOT a mechanical property influencing vocal fold vibration?

The correct choice centers around recognizing that temperature is not a mechanical property that influences vocal fold vibration. Mechanical properties typically refer to how materials respond to physical forces and include tension, mass, and length.

Tension refers to the tightness of the vocal folds and affects how quickly they can vibrate—more tension generally leads to higher frequencies of vibration. Mass is the amount of substance in the vocal folds and directly impacts the speed and nature of the vibration; heavier vocal folds typically vibrate more slowly, producing lower pitches. Length also plays a significant role; longer vocal folds generally produce lower pitches while shorter ones tend to generate higher frequencies.

Temperature, while it can affect vocal production in terms of the physical state of tissues and potentially overall health, doesn't directly alter the mechanical properties of the vocal folds themselves in the same way as tension, mass, and length do. Thus, it is not considered a mechanical property impacting vocal fold vibration.