I got this question from an elite voice adviser.
“Regarding the figure of the thyroid cartilage shape when producing fluctuating pitches: Is it true that it is easy to let out a low-pitched voice when the shape is narrowed and if it’s widened it is easy to let out a high-pitched voice? Also, what is the reason behind this?”
I’ll explain and answer below.
If you see the thyroid cartilage from the top, it almost looks triangular.
Please refer to the figure below.
The a’& a are top, b&b’ and c&c’ are bottom of triangle. The left figures shows the shape of the thyroid cartilage when narrowed, and the right figure shows the thyroid cartilage when the shape is widened.
a&a’ are projections of the pharynx viewed from the front side, b,d,c&b’,d’,c’ are the back side, b&b’ are the left side and c&c’ are the right side.
The vocal cord line is a or a’ through d or d’.
When comparing the two triangles, a from d has a longer line length than a’ from d’. This means that the right vocal cord is shorter than the left one.
The elongated vocal cord is in connection to the reason behind how the voice pitch fluctuates, assisting in producing a low-pitched voice and the shorter vocal cord assists in producing the high-pitched voice.
These are the source mechanics of pitch production. When comparing these mechanics to the strings of a musical instrument, the same is true. Longer/thicker strings make a low pitched sound and shorter strings make a higher pitched sound.
However, you have to consider the size of the vocal cord as well. It displays a degree of thickness but not exactly like instrumental strings.
To answer the vocal advisor’s question, the statement is true. The figure of the thyroid cartilage shape, when narrowed does indeed make it easier to let out a low-pitched voice, meanwhile, when it is widened, it is easier to let out a high-pitched voice.
The male thyroid cartilage is generally larger and narrow in shape, whereas the female thyroid cartilage shape is smaller and wide. The left one looks like male thyroid cartilage and the right one looks female, in the above figure.
Please take into consideration, that each person does have individuality and the measurements do vary.
What kind of a thyroid cartilage do you have?