Formant frequencies resonate the loudest at which parts of a vowel?

Formant frequencies, which are key to understanding the acoustic properties of vowels, resonate most strongly during the steady state portion of a vowel. This part of a vowel sound represents a period where the articulatory configuration of the vocal tract is stable, allowing for maximum resonance enhancement of the formant frequencies.

During steady states, the configuration of the oral cavity reaches a specific shape, which shapes the resonating frequencies. This is particularly important because the formants are critical for vowel identification and classification in speech. The steady state facilitates the distinct formant patterns that characterize different vowel sounds.

In contrast, transient states refer to the rapid changes at the beginning and end of a vowel sound, which do not contribute to the sustained resonant properties of the formants in the same way. The initial phases and terminal overlaps are areas where the speech signal is in transition, typically involving changes in articulatory position or the blending of sounds, thus lacking the necessary stability for resonant peak formation.

Therefore, the steady state portion stands out as the critical phase for the loudest resonance of formant frequencies in vowel production, making it the correct answer.