What role do the nasal and oral cavities play in speech?

The nasal and oral cavities play a critical role in the production of speech sounds and tones, which is why the answer focuses on their involvement in this process. When speaking, the shape and size of these cavities can alter resonance and airflow, contributing to the quality, pitch, and articulation of sounds produced by the vocal cords.

The oral cavity, including the tongue, teeth, and lips, is particularly crucial in shaping sounds through articulatory processes such as stops, fricatives, and vowels. The nasal cavity adds additional resonance, especially in nasal sounds like /m/, /n/, and /ŋ/. By manipulating these cavities, speakers can produce a wide variety of sounds that are essential for effective communication, allowing for the articulation of all phonemes used in language.

In contrast, while the nasal and oral cavities do support breathing, that is not their primary role in speech production. Moreover, while they are indirectly connected to hearing comprehension through the overall function of communication, their main function in this context centers on producing and modifying sound rather than facilitating comprehension directly.