Final answer:
The statement that paranasal sinuses act as resonating chambers to alter one's voice is TRUE. The sinuses contribute to the resonance and timbre of our voice, and changes in voice during congestion illustrate their effect.
Step-by-step explanation:
It is TRUE that paranasal sinuses act as resonating chambers that contribute to voice quality by adding resonance. The sinuses are air-filled cavities located in various bones around the nasal cavity. They are lined with mucosa and connect to the nasal cavity. The primary function of the paranasal sinuses includes reducing the weight of the skull and warming and humidifying the air we breathe. However, they also play a significant role in the resonance and timbre of our voice. When these sinuses are obstructed, such as during a cold or sinus congestion, you might notice a change in your voice, which illustrates the impact they have on the sound we produce.
In essence, the throat and mouth, along with the tongue, modify the spectrum of overtones produced by the vibration of the vocal cords, but the shape and volume of the paranasal sinuses also contribute to the unique character of an individual's voice by acting as resonating chambers. These differences are especially noticeable when comparing voices between different sexes, particularly after puberty, when the larynx grows and alters the resonant cavity in males.