[Voice parameters in normal children measured with computer]

Computer was used to measure and analyse voice parameters in 119 normal children aged 4-12 yrs. The values of pitch perturbations (Jitter) were 0.037 +/- 0.016 ms in the male and 0.044 +/- 0.017 ms in the female without significant difference among different age groups. In general, no remarkable significance was shown between both sexes (P less than 0.05). Percentages of jitter (JR) were 1.2 +/- 0.53% in the male and 1.45 +/- 0.56% in the female. JR values in the female were higher than those in the male, the difference of which became marked as ages went on. At the age of 12, the difference appeared to be significant (P less than 0.05). Amplitude perturbations (Shimmer) were 0.45 +/- 0.26 dB, no difference between both sexes was noted. The differences among age groups were significant (P less than 0.05 or P less than 0.01). Harmonics-to-Noise (H/N) ratio was 14.92 +/- 2.74 dB, there was no difference between the male and the female. Significant differences were present among different age groups (P less than 0.05).