The fundamental frequency, or $f_{0}$, of a periodic signal is the frequency of the lowest-order [[harmonic components]] of the signal. The fundamental frequency of a [[speech signal]] is the frequency of the vibration of the [[vocal folds]] when [[voiced phonation]] is produced. The subjective perception of the fundamental frequency of a sound is referred to as [[pitch]]. Since the vibration of the vocal folds depends on the size of the larynx, the average fundamental frequency is different for male voices (130 Hz) and female voices (220 Hz). In normal speech, the average range of variation of the fundamental frequency is 1 octave. For singing voice it changes to 2 octaves. The fundamental frequency of a discrete-time signal, $f_{0}$, expressed in Hz or samples per second is the inverse of the [[fundamental period]], $N_{0}$: $ f_{0} = \frac{1}{N_{0}} $ The fundamental frequency can also be expressed in radians per second: $ \omega_{0} = \frac{1}{N_{0}} $ Since the [[speech signal]] is a [[non-stationary signal]] the fundamental frequency is computed using [[short-time processing]].