# Impact of Audio Delay and Quality in Network Music Performance +
## 5 Evaluation Results
### Scenario A: Audio Delay
In Figure 9, we can see the results for the I was Trying to Follow my partner (TTF) question. The regression line has a positive slope, similar to that of PoAD in Figure 5, but starting from 2.8 and ending at 3.9. The responses are widely spread for all M2E delays, as indicated by the dispersion and sizes of the dots, showing a split between leading and following; this is similar to what we would see in a non-NMP scenario. However, at 40 ms, and even more clearly at 60 ms, we see more answers with higher scores, indicating that as synchronization is lost, each musician relies more on the other one. An issue that has not been considered in previous studies is whether musicians focus more on aural or visual contact during an NMP session. Figure 10 shows the answers to the Did you focus on audio or video? question. The regression line is nearly flat at 4.3 with low variance, implying a very strong preference for audio contact, even though the video delay was only 15 ms, while the audio delay increased all the way up to 60 ms. This is clear evidence that musicians in an NMP setting mostly rely on aural rather than visual cues for synchronization, amplifying the conclusions of previous research indicating that synchronization relies more on aural cues. Figure 11 shows the results for the Did you feel anxiety? question, where the regression line is almost horizontal at 1.2, indicating nearly zero anxiety. This is complemented by Figure 12, which shows the results for the Did you feel irritation? question, where the regression lines go from 1 to 1.7, even at the largest M2E delay values, indicating no to minor irritation. These responses show that the musicians felt comfortable performing with our NMP setup, thus allowing us to place more trust in the responses to the other results, as past studies have found that when participants are uneasy during their performance, they provide lower scores to other (often, unrelated) questions. Figure 8: Perception of satisfaction (Pianists and Partners, N = 6), 95% confidence, Adj. R\({}^{2}\) = 0.88. Figure 9: Results for the T was trying to follow my partner’ question (N = 22), 95% confidence, Adj. R\({}^{2}\) = 0.85. To assess the statistical significance of our findings, we conducted a repeated measures ANOVA study. The independent variable in this analysis was the audio delay, while the dependent variables included Perception of Synchronization Degr (PoSD), Perception of Audio Delay (PoAD), Perception of Satisfaction (PoSat), and Trying to Follow (TTF). We excluded the remaining variables from this analysis, as their regression trends did not suggest any correlation with delay. The results, encompassing all 22 participants, are presented in Table 4.  
As shown, most \(p\)-values fall below the standard significance threshold of 0.05, suggesting a strong likelihood of correlation between the respective variable and audio delay. \begin{table}
\begin{tabular}{l l l l l} \hline Dependent Variable & PoSD & PoAD & PoSat & TTF \\ \hline Independent Variable & delay & delay & delay & delay \\ \hline Samples & 22 & 22 & 22 & 22 \\ \hline \(p=0.05\) & 0.001 & 0.013 & 0.819 & 0.002 \\ \hline \end{tabular}
\end{table} 
Table 4: ANOVA results: delay vs. subjective results. Figure 11: Perception of anxiety (N = 22), 95% confidence, Adj. R\({}^{2}\) = \(-0.06\). Figure 12: Perception of irritation (N = 22), 95% confidence, Adj. R\({}^{2}\) = 0.96. Figure 10: Focus on audio or video (N = 22), 95% confidence, Adj. R\({}^{2}\) = \(-0.14\). The only exception is PoSat, which yielded a \(p\)-value of 0.819. This lack of statistical significance can be explained by the generally high satisfaction scores observed across all delay conditions, even the largest ones.