## 3 Results
For women, there were no significant differences in certain jitter parameters, such as jitter local rap and jitter ppq5. The schematic in Figure 1f shows the perturbation of the glottic vibration, indicating the amplitude of the sound wave. This is related to changes in the degree of voice breathiness and intensity variations. Similar results in Figure 1g-i are from the study of acoustic parameters, such as shimmer local (dB), apq3, and apq5, which describe similar speech characteristics. According to the results, the shimmer was significantly lower in young men than in elderly men. However, in females, no significant difference was observed in the shimmer, which tended to be constant in elderly female voices and mostly increased in young female voices. The shimmer did not change considerably with respect to age in women. These results agree with indications that age-related changes in the larynx are greater in men than in women and may begin earlier in males [36]. The mean N/H in Figure 1j shows the amount of noise associated with the harmonics of the waveform: the higher the value, the lower the overall sound quality level. The results show that the parameter values were much higher in older people of both sexes (women and men over the age of 60). Noise is caused by changes in frequency and amplitude (jitter and shimmer), subharmonic components, and instantaneous voice interruption; thus, the reliability of the above results is supported. The mean N/H in Figure 1j also confirms that voice aging leads to a general deterioration of speech quality that can be objectively measured. The mean H/N dB shown in Figure 1k defines the relationship between the intensity of harmonic and nonharmonic components in the overall spectrum of the measured voice signal. The greater the value, the clearer the speech quality. In this study, older male subjects scored much lower than younger males, indicating that the vocal performance was worse for men than women over the age of 60. The reduction in harmonic components can be explained by changes in the resonant structure of the vocal tract. \begin{table}
\begin{tabular}{l l l l l l} \hline \hline  & & **Men** & \multicolumn{2}{c}{**Women**} \\ \hline  & & **Young** & **Elderly** & **Young** & **Elderly** \\ \hline The normalized skewness & Arithmetic mean & \(-\)0.133 & \(-\)0.141 & \(-\)0.080 & 0.182 \\  & 95\% CI for the mean & \(-\)0.238\(-\)0.026 & \(-\)0.205–0.143 & \(-\)0.340–0.182 & \(-\)0.046–0.384 \\  & SD & 0.054 & 0.092 & 0.135 & 0.110 \\  & \(p\) value & 0.65 & & 0.005 \({}^{\star}\) & \\ \hline The normalized kurtosis & Arithmetic median & 2.976 & 2.483 & 2.722 & 2.539 \\  & 95\% CI for the median & 2.846–3.333 & 2.275–2.601 & 2.461–2.989 & 2.311–2.751 \\  & SD & 0.156 & 0.092 & 0.121 & 0.147 \\  & \(p\) value & 0.011 \({}^{\star}\) & & 0.494 & \\ \hline \hline \end{tabular} Note: \({}^{\star}p<0.05\).  
\end{table} 
Table 3: Means, 95% CIs for the mean and median, and SDs for all parameters analyzed with higher-order statistics (HOS). Figure 2 shows the results of the analysis with TF32. F0 (Figure 2a) tended to increase in elderly male voices and decreased in elderly female voices, yielding significant differences from values extracted from Praat. Ppd (Figure 2b) presents the pitch period in milliseconds. As the frequency and period are reciprocal, the graphs of F0 and pitch period have opposite trends. Therefore, F0 tended to decrease in elderly male voices and increase in elderly female voices, and the difference was significant. Jitter (Figure 2c) is the cycle-to-cycle variation in the pitch period during voicing. Shimmer (Figure 2d) is the variation in amplitude between cycles. The SNR (Figure 2e) compares the magnitude of a voice signal to the magnitude of the aperiodic component as defined by the TF32 manual. They tend to be similar to the values extracted through Praat. For men, all acoustic parameters extracted from Praat and TF32 yielded significant results (\(p<0.05\)).