# Sound Environments in Large Public Buildings for Crowd Transit: A Systematic Review
## 3 Results
### Museums/Exhibition Spaces  
[PERSON] and [PERSON] [26] surveyed the courtyard of the Rahmi M. Koc Museum and its corridor, which was also an exhibition space, and one large exhibition space of the Erimtan Archaeology and Arts Museum in Ankara, Turkey to further generate a systematic categorization of museum content by exploring the visitor perception. The height of the investigated spaces of the former was 3.5 m for the first floor and 10.5 m for the courtyard, and that of the latter was 10.6 m. \(L_{\text{Aeq-20 min}}\) were measured on a weekend as 95.6 dB (\(L_{\text{Amax}}\): 97.5 dB, \(L_{\text{Amin}}\): 91.7 dB) in the former, and 94.4 dB (\(L_{\text{Amax}}\): 96.5 dB, \(L_{\text{Amin}}\): 93.1 dB) in the latter. It is worth mentioning that these sound levels in public buildings appear to be exceptionally high, but the authors do not provide further details. Following the guidance of ISO/TS 12913-2 about semi-structured interviews and five-point Likert scales for surveys, the investigated perceptual attributors were mainly \"appropriate\", \"calm\", \"concentrating\", \"curious\", \"disturbing\", \"high\", \"positive\", \"uncomfortable\", etc. It was concluded that visitor perceptions were mostly based on the sound contexts, rather than sound levels, even if measured sound levels were relatively high. [PERSON] [27] conducted in situ tests in Hagia Sophia of Istanbul in Turkey and particularly simulated the exhibition states with a marble floor. The volume of each individual space ranged from 625 to 95,960 m\({}^{3}\). To determine the sound energy decays that occur in the different states of the space, the research considered several decay parameters and the degree of acoustical coupling. Among the many variables, the source-receiver distance and positioning within different sub-spaces appear to be the underlying determinant of multi-slope sound decay patterns. No subjective surveys were performed in this study. [PERSON] et.al. [28] selected a highly attended exhibition space in the Archaeological Museum of Florence, Italy, assessing the reliability of a predictive dynamic model. The room was 28.0 in length, 9.30 in width, and 11.0 in height, and reverberation time-averaged over the octave band 500 to 1 kHz was 3.3 s. The objective measure included visitor flow,  
Figure 1: Flow of information through the different phases of the systematic review [24]. \(L_{\text{Aeq-1 min}}\), and the number of people inside the spaces during a free-entrance day. The software simulation model involved the SPL attenuation among the visitors, Lombard slope and group size, communication quality related to SNR, and association between the number of visitors and acoustic condition. No subjective surveys were carried out in this study. [PERSON] and [PERSON] [29] investigated two comparable sets of small box-shaped sequential exhibition spaces, of which one was equipped with a large-scale sound installation, in Tate Modern London, UK. The dimensions of small spaces were similar as 6.3 m in width, 6.3 m in length, and 4.9 m in height, with one exception of 13.0 m in length, 9.0 in width, and 9.8 in height. \(L_{\text{Aeq-1 min}}\) were measured between 66.8 to 39.7 dB in unoccupied condition, and from 68.3 to 58.8 dB in occupied condition on weekdays and weekends. To collect individual response of each space in sequence, the researchers conducted indoor soundwalks with two groups of subjects moving in opposite directions on the same path (i.e., towards/away from the primary source). Twelve perceptual attributes were extracted from both room acoustics and soundscape using five-point Likert scales, as \"loudness\", \"clarity\", \"reverberance\", \"spaciousness\", \"listener envelopment\", \"intimacy\", \"warmth\", and \"stage support\" for the former, and \"directionality\", \"annoynace\", \"acoustic comfort\" and \"overall impression\" for the latter. Perceptual loudness and listener envelopment were demonstrated to be statistically significant when users moved in two opposite directions to/from the primary source. [PERSON] et al.