singleformant

In acoustics and speech science, a formant is a resonance peak in the frequency spectrum produced by the vocal tract or other resonant system. A singleformant refers to focusing on one such resonance, as opposed to analyzing the full set of formants that typically shape a vowel or voiced sound.

Vowels and many voiced sounds exhibit multiple formants, but singleformant analyses are used for coarse spectral description, perceptual experiments with limited bandwidth, or simplified synthesis models. The single formant frequency is estimated by inspecting spectral peaks via methods such as FFT, LPC, or cepstral analysis; the formant's bandwidth provides damping information.

Applications include linguistic experiments examining the perceptual salience of individual resonances, low-complexity speech synthesis or vocoding, and analysis of non-speech sounds with a prominent resonance, such as musical tones or instrument timbres. The approach is limited because much of vowel identity and timbre depends on multiple formants and their relative spacing; using only one formant can misrepresent spectral shape and degrade intelligibility or naturalness.

Related terms include formant, formant frequency, LPC, cepstrum, spectral peak, and vowel space.