This allows the piano strings to stay in tune and make a predictable sound. At younger ages when flexible cartilage supports the vocal folds, there is a greater chance for unpredictability, but with stiffer, more bony supports, it is logical that the voice could perform more reliably. Other changes in middle age can be less beneficial to the voice. As various muscles and connective tissue in the vocal folds atrophy or degenerate with age, it can become more difficult to make the voice perform normally. Since the thyroarytenoid muscle helps to control pitch, intensity and register, any loss of function in that muscle will have an adverse effect on vocal performance.
Some cells become dystrophic with age and no longer perform their normal tasks.
Muscle fibers lose their ability to obey nerve impulses telling them to contract. Nerve cells lose the ability to transmit neural signals properly. As a result, the voice may become weak or fluttery. Finally, edema or swelling of the vocal fold cover interferes with the normal vibration of the folds, which can lower the voice, or cause roughness.