What does F2 correspond to in relation to the vocal tract?

F2, or the second formant frequency, primarily corresponds to the oral cavity in the context of speech sounds. The formants are resonant frequencies of the vocal tract, and their positions are influenced by the shape and movements of the vocal tract during speech production.

F2 is particularly significant in distinguishing different vowel sounds. It is mainly affected by the positioning of the tongue and the size of the oral cavity, which can change as the tongue moves forward or backward and the jaw opens or closes. Thus, F2 is greatly influenced by the resonances created in the oral cavity as sound waves travel through it, making it crucial for vowel identification and articulation in speech.

In contrast, the other cavities listed do not have the same direct relationship with F2. The pharyngeal cavity is important but more directly influences the first formant (F1) and does not specifically shape F2 in the same way as the oral cavity. The nasal cavity primarily affects nasal sounds and resonance but is not the most relevant for F2. The tracheal cavity is the airway leading to the lungs and does not serve a role in the resonant properties that formants represent.