# Open-Plan Offices: Comparison of Methods for Measuring Psychoacoustic Intelligibility Parameters
## 3 Results
### Acoustic Analysis of Intelligibility
#### 3.2.1 Analysis by Objective Methods
Office noise emission was favored with a negligible effect, with an \(STI\) = 0.71 \(\pm\) 0.14 (\(p\) < 0.001, d = 0.19); Point 5 varied the levels averaging with a medium effect and an \(STI\) = 0.77 \(\pm\) 0.16 (\(p\) = 0.004, d = 0.56); Point 5 varied with a medium effect and an \(STI\) = 0.77 \(\pm\) 0.16 (\(p\) = 0.004, d = 0.56); Point 12 varied with a negligible effect and an \(STI\) = 0.71 \(\pm\) 0.14 (\(p\) < 0.001, d = 0.19); Point 12 varied with a medium effect, averaging an \(STI\) = 0.59 \(\pm\) 0.16 (\(p\) = 0.004, d = 0.56). This point was located next to the glass walls and in an area without changes in \(SPL\); Point 13, with a small effect presented at \(STI\) = 0.59 \(\pm\) 0.18 (\(p\) = 0.005, d = 0.19), was located at the center of other cubicles and in an area without changes in (Figure 5). In addition, the characteristics of the materials influenced the correlation between the assignment of measurement points and \(STI\) levels. Here are some examples:  
* In areas with SPL changes, point 5, surrounded by worktables, had a medium effect, and increased \(STI\) levels (\(\beta\) = 0.0692, d = 0.56). However, point 8, which is close to sound-reflecting glass walls with a negligible effect, caused a decrease in \(STI\) levels (\(\beta\) = \(-\)0.0673, d = 0.06) when interacting with office noise emission. * In areas with stable \(SPL\), some measurement points stand out: \(\odot\) Point 12, close to glass walls and a corridor, showed a medium effect, a decrease in \(STI\) levels (\(\beta\) = \(-\)0.0924, d = 0.56), which continued this trend up to Point 13, decreasing \(STI\) levels (\(\beta\) = \(-\)0.0894, d = 0.56). \(\odot\) Point 16 stands out because interacting with the office noise emission produced a negligible decrease in \(STI\) levels (\(\beta\) = \(-\)0.0673, d = 0.06). However, at Point 3, when the office noise emission came from external sources, it presented a medium effect in decreasing \(STI\) levels (\(\beta\) = \(-\)0.1279, d = 0.57). * The type of sound was another main effect that influenced the behavior of the \(STI\) level, particularly office noise:  
Figure 4: Points with significant changes in \(EDT\). This diagram shows the points and sound sources with significant changes in the average values during the study. When the emission came from sources outside the work area, there was a negligible decrease in _STI_ levels (\(\beta=-0.0499\), d = 0). When the emission came from both sound sources with a negligible effect, there was a decrease in _STI_ levels (\(\beta=-0.048\), d = 0). * The location of the external sound source, Source A, also influenced _STI_-level behavior:
* When the external sound source located to the right (L1A) was combined with any internal sound source to emit both office noise, there was a medium effect in decreasing _STI_ levels (\(\beta=-0.0405\), d = 0.36). When the office noise emission came from either source location A, Point 8 near glass walls had a small effect on decreasing _STI_ levels (\(\beta=-0.1533\), d = 0.24). In contrast, Point 10 located between work modules near wooden stairs, had a large effect on decreasing _STI_ levels (\(\beta=-0.109\), d = 0.60) (Table 2).