## 4 Discussion  
The results show the GATs are longer in the AdSD group than in the normophonic group, which was confirmed by the generalized linear model analysis. The average GAT was 16.8 and 14.7 ms in the AdSD and normophonic groups, respectively. This was supported by previous research that showed a longer latency between the muscular activation and the phonation onset in AdSD compared to the normophonic voices [29]. Moreover, the steady-state onset delay, the time between the first oscillation and a steady-state oscillation, was observed to be longer in AdSD than in the normophonic voices [18]. While the steady state delay measure is different from the GAT measure in this study, the findings are in line with those of the current work. The GAT values in this study were longer than the GATs measured by [PERSON] et al. [25] for comfortable productions of several sustained vocalizations. The difference between our measurements and those of [PERSON] et al. could be due to the shorter vocal attack times for the selected vowel in their study, while our  
Figure 5: GAT values (in ms) for different vocalizations (\(x\)-axis) for the normophonic voices (panel (a)) and AdSD (panel (b)). The subject IDs are shown in the legend. study measures the GAT for different vocalizations in connected speech. Although the average GOT was slightly shorter in the AdSD group (25.4 vs. 26.4 ms), the parametric and non-parametric analysis did not show any significant differences between the AdSD and normophonic groups. The longer GAT and slightly shorter GOT were also observed in a previous study by our group with a smaller sample size and a different data collection HSV system [28]. A greater variability was observed in both the GAT and GOT in the AdSD group, which was expected as the disorder led to more uncertain behaviors and irregularity in the vibrations of the vocal folds. Considering that the AdSD patients have less neurological control over their laryngeal muscles during voice production [30; 31; 32], the longer GAT and the higher variability in the GAT and GOT of AdSD can be explained. The AdSD patients showed nonstationary vocal fold dynamics with large variations in the GAT and even larger ones for the GOT. The dynamics of vocal fold vibration in the normophonic patients were stationary with small variations in the GAT and larger variations in the GOT. The more volatile behavior of the GOT in the normophonic group than that of the GAT was also observed through the larger number of outliers in GOTs. Therefore, GAT might be a more valuable measure than the GOT since it was found to be statistically different between the normophonic and AdSD groups and a more stable measure within the normophonic group. The high correlations between the GAT and GOT values in both groups indicate that the participants with greater GAT values also tend to have greater GOTs and vice versa. A larger number of onsets and offsets with zero GAT and GOT was observed in the AdSD group which could be related to the disorder. Therefore, the number of the hard glottal attack/offset could be potentially used as another measure to characterize the AdSD. The AdSD group also showed a lower average number of onsets and offsets with measurable GATs/GOTs. This was due to the more excessive laryngeal maneuvers in connected speech in the AdSD group that led to more blockage of the view of the vocal folds and a smaller number of measurable GATs/GOTs. No effect of sex and age was observed using the generalized linear model, which could be due to the small sample size in this study. The comparison of GAT/GOT measured for the true and false vocal folds in S3M showed some overlap. As the false vocal folds' vibration is a compensatory strategy, more variability and extreme values were observed for GATs/GOTs of the false vocal folds. The GAT and GOT values for the false vocal folds in S3M were the highest among the AdSD group.