What is a key characteristic of second formant frequency (F2)?

The key characteristic of the second formant frequency (F2) is that it reveals place of articulation information in stop consonants. F2 is particularly important in distinguishing between different vowel sounds, as it corresponds to the frequency of the second resonant peak that occurs in the vocal tract during speech. However, in the context of stop consonants, it is crucial because it helps to identify certain articulatory configurations, reflecting how far back in the oral cavity the constriction occurs when producing specific consonants. For instance, the F2 frequency can help differentiate between bilabial, alveolar, and velar stops, contributing to our understanding of the phonetic characteristics of these sounds.

The other options focus on aspects of speech that do not pertain to the function of F2 in stop consonants. F2 does not provide direct information about vowel height, which is primarily indicated by the first formant frequency (F1). It does not correlate with the loudness of speech, which is more influenced by amplitude rather than frequency. Lastly, F2 is not utilized to measure the rate of speech production; other metrics are typically used for that purpose. Thus, the role of F2 in signaling place of articulation makes it a key characteristic in speech science