formantok

Formantok, or formants, are resonant frequencies of the vocal tract that shape the spectral envelope of voiced sounds. They arise from the vocal tract acting as a filter on the glottal source, with their exact values determined by the geometry of the oral cavity and the position of the tongue, lips, and jaw.

In practical analysis, formants are identified as peaks in the frequency spectrum of speech, typically obtained through short-time Fourier analysis or linear predictive coding. The first three to five formants (F1, F2, F3, …) capture the major characteristics of vowels; higher formants are less informative for vowel identity.

The primary associations are F1 with vowel height and F2 with vowel backness: high vowels tend to have low F1, front vowels have high F2, and back vowels have lower F2 values. F3 can reflect rounding or specific vowel qualities but is less systematic. Formant values depend on the speaker’s vocal tract size and on coarticulation with surrounding sounds. Consequently, cross-speaker comparisons often use normalization or vowel-space plotting to compare vowels across speakers.

Applications of formant analysis include linguistic research (vowel space studies), speech synthesis and recognition, and language learning tools that illustrate how tongue position affects formant frequencies. While formants provide important cues for vowel identity, they are part of a broader set of acoustic and perceptual cues used in speech processing.