Pitch Estimation and Voiced–Unvoiced Classification of Speech - Digital Speech: Coding for Low Bit Rate Communication Systems - page 150

Lag Values

0 40 80 120 0 40 80 120 0 40 80 120 0 40 80 120

Normalised
Autocorrelation

Speech Signal

0 160 320 480 640

Samples

Figure 6.2 Autocorrelation and speech signal. The maxima of the autocorrelation
function corresponding to the pitch values are indicated by circles

(a)

Window

(b)

Lag

0

(c)

0

Lag

Pitch

Figure 6.3 Autocorrelation of speech: (a) original speech, (b) direct autocorrelation
function and (c) normalized autocorrelation function