What are resonant (formant) frequencies commonly measured in?

Resonant frequencies, often referred to as formant frequencies in speech science, are the specific frequencies at which the vocal tract naturally vibrates. These frequencies are measured in Hertz (Hz), which quantifies the number of cycles per second of a wave.

In the context of speech, formants represent the resonant peaks of the harmonic spectrum and are crucial for distinguishing different vowel sounds. Since frequencies are inherently a measure of oscillation and wave phenomena, Hertz is the appropriate unit to utilize.

The other units mentioned—decibels, pascals, and watts—serve different purposes within acoustics and sound measurement. Decibels measure sound intensity and pressure levels, pascals quantify pressure, and watts represent power. None of these units measure frequency, making Hertz the only relevant option for expressing resonant or formant frequencies.