Acoustic Analysis of Normal Voice Patterns in Pakistani Adults.

This study was designed to find out normative acoustic measures of adults in Pakistan. Age and gender differences in these parameters were also studied. The study variables include fundamental frequency, absolute jitter, relative jitter, relative average perturbation, 5-point period perturbation quotient perturbation quotient, jitter average absolute difference between consecutive periods, divided by the average period, shimmer local, shimmer decibel, three-point amplitude perturbation quotient, five-point amplitude perturbation quotient, average absolute difference of consecutive differences between the consecutive periods' amplitudes, and harmonics-to-noise ratio. Participants (N = 71; men = 34; women = 37) were recruited through two-stage sampling; convenience and purposive sampling. Participants were selected from students, staff, and faculty of the University of the Punjab, caretakers of the clients coming for clinical services, and researchers' friends, family, and acquaintances. Gender groups were further divided into three subgroups based on the age bands of 21-30, 31-40, and 41-50 years. After screening for health issues, the voice samples were recorded in a sound-proof acoustic laboratory by using a stand-held microphone and Praat software. Praat was also used for voice analyses. Means and standard deviations were conducted for the participants. Age and gender differences were investigated by using the two-way analysis of variance. Normative values were also measured for men and women between the age bracket of 21 and 50 years. Age differences were not significant for any variable. Gender differences were significant in fundamental frequency, absolute jitter, relative jitter, jitter period perturbation quotient, shimmer five-point amplitude perturbation quotient, and harmonics-to-noise ratio. The interaction between age and gender was significant in all the jitter measures. The interaction showed an increase in all these measures between the ages of 31 and 40 years and a decrease between the ages of 41 and 50 years in women, whereas men showed a reverse effect both in the age ranges of 31-40 and 41-50 years.