The frequencies of possible standing waves in vocal cords, like all standing waves, depend on the length of the confined wave, L, (length of the vocal cords) and the velocity, v, of the medium (the velocity of the wave in the vocal cords). The velocity depends on the restoring mechanism and the inertia of the medium. The vocal cords velocity can be approximately modeled as a wave on a string with v = (T/)1/2, with T is the tension and is the mass per length. The mass per length, , can be considered a measure of the vocal cord "thickness." f = /"" = (T/) L = n /"2". n = 1, 2, 3,... n=1 is called the fundamental

What is the effect of the longer vocal cords (alone) in males, relative to females

1) a) Increases "L" b)Decreases "L" c)No effect on "L". Answer:

2) a)Increases b)Decreases c)No effect on . Answer:

3)a)Increases "T" b)Decreases "T" c)No effect on "T" Answer:

4)a)Increases "" b)Decreases "" c)No effect on ". Answer:

5) a)Increases "v" b)Decreases "v" c)No effect on "v". Answer:

6)a)Increases "f" b)Decreases "f" c)No effect on "f". Answer:

You can also often recognize an older adult vs. a young adult by the sound of their voice. This depends on the changes in thickness of the vocal cords, which is influenced by changes with age in levels of testosterone or the testosterone/estrogen ratio. F₀ below refers to the fundamental frequency. Males with age :"For men, the decrease in F₀ that is most dramatic during puberty has been observed to continue with successive deceleration until about 35 years of age At about 55 years of age, F₀ begins to rise again (Hollien and Ship, 1972; Kitzing, 1979; Pegoraro-Krook, 1988)."https://www2.ling.su.se/staff/hartmut/f0_m&f.pdf This is due to the decrease, in males, of testosterone with age.

Females with age: "For women, F₀ is stationary up to the age of menopause, when it decreases to reach a minimum that is about 15 Hz lower around 70 years of age (Chevrie-Muller et al., 1971; Kitzing, 1979; Stoicheff, 1981; Pegoraro-Krook, 1988). The physiological changes responsible for this can be understood as an effect of the increased testosterone-oestrogen ratio."The increased testosterone/estrogen ratio, in aging women, is due to the decrease in estrogen:

What does the decreased testosterone level in older males do:

1) a) Increases "L" b)Decreases "L" c)No effect on "L". Answer:

2) a)Increases b)Decreases c)No effect on . Answer:

3)a)Increases "T" b)Decreases "T" c)No effect on "T" Answer:

4)a)Increases "" b)Decreases "" c)No effect on ". Answer:

5) a)Increases "v" b)Decreases "v" c)No effect on "v". Answer:

6)a)Increases "f" b)Decreases "f" c)No effect on "f". Answer:

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