What effect does a decrease in the elasticity of vocal folds have?

A decrease in the elasticity of the vocal folds primarily leads to a lower frequency of vibrations. Vocal fold elasticity is crucial for how well they can stretch and return to their original shape during vibration. When elasticity decreases, the vocal folds become stiffer and less capable of rapid oscillations, which results in slower vibrations and consequently a lower pitch of the voice.

In terms of vocal production, lower frequency vibrations correspond to lower pitches. This phenomenon is due to the inverse relationship between frequency and the tension and mass of the vibrating body—in this case, the vocal folds. Therefore, a reduction in elasticity directly affects the vibratory characteristics, resulting in a deeper or lower voice. This physiological concept is fundamental in understanding how various factors influence pitch and vocal quality.