formantstrukturer

Formant structures, in speech science often referred to simply as formants, are the resonant frequencies of the vocal tract that shape the acoustic character of spoken sounds. They arise when the vocal tract acts as a filter on the glottal sound source produced by the vocal folds. The result is a spectrum with several prominent peaks, or formants, that listeners associate with different vowels and some consonants.

In vowels, the most important formants are F1 and F2. F1 is generally inversely related to vowel height (higher F1 for open vowels), while F2 is related to the frontness of the tongue (higher F2 for front vowels and lower F2 for back vowels). A third formant, F3, is influenced by tongue position, lip rounding, and other articulatory factors, though it is less reliably tied to a single articulatory parameter than F1 and F2. The complete formant pattern provides a distinctive acoustic signature that helps listeners identify vowel quality. Formants are also present in certain consonants, particularly voiced ones and fricatives, but they are most stable and salient in vowel sounds.

Formant structures are analyzed using spectrograms and auditory perception models. They are often expressed in terms of the Bark or Mel scales to reflect perceptual spacing. Variation in formant structures occurs across speakers, dialects, speaking styles, and language, contributing to the acoustic vowel space and aiding language identification. Applications include automatic speech recognition, speech synthesis, language documentation, and clinical phonetics.