Returning to Faith, whom we met earlier, we may recall that she lost her voice suddenly for no apparent reason. When she went to her primary physician, he predicted that she would improve with time. Indeed she did. After a few weeks, some voice returned. Her voice was higher pitched and softer than before, but seemingly her physician was correct, she would get better on her own.
Still, after several more weeks, Faith was unsatisfied with her merely marginal improvement. At a follow up visit with her primary physician, she was referred to an otolaryngologist. Still she failed to improve with various treatments. Several months later she appeared in my office still hoarse.
As she tells me her story, I listen to her voice. Next, I asked her to start at a high note and gradually descend to the lower pitched notes. At the highest notes, her voice is fairly clear and fairly robust. At a lower pitch, approaching the typical speaking pitch for a female, she loses volume and below that pitch, her voice becomes very rough. We repeat the task several times. Her voice fading in volume and quality at low pitch is very consistent.
When I observe her vocal cords as she descends toward the lowest pitches where her voice becomes rough, I can see one vocal cord become loose, bow, buckle and ultimately flutter in an irregular pattern.
Faith’s rough vocal quality is due to an uneven tension between the vocal cords. The uneven tension is partially compensated at high pitch, remaining subtle and hidden. Her comfortable speaking pitch is automatically higher than it used to be as she unconsciously tries to compensate for her voice problem by tightening the vocal cords to avoid the flutter. In her lower range, however, the difference in tension is pronounced and at some point each vocal cord vibrates at a separate pitch.
To describe these two separate pitches occurring simultaneously (diplophonia), I could use terms such as roughness or gravelliness to describe her low voice, while she might say, “I am hoarse” or “My voice is rough.” Two pitches produced simultaneously and sonically competing with each other are irregular vibrations. Faith’s roughness is due to uneven tension.