## 5 Conclusions  
This paper presents the representative case study of the monitoring of the Turin Cathedral bell tower. First of all, the damage evolution in a portion of the external bearing walls is described by the evaluation of the cumulative number of AE and by different parameters able to predict the time dependence of the damage. In particular, the \(b\)-value analysis showed a decreasing trend down to values in the critical phase well-matching with the growth of the localized macro-cracks in the masonry portion near to the base of the tower. The AE results were found in good agreement with the numerical simulations implemented by Midas software (CSP Fea Engineering, Padova, Italy). To obtain an improvement in the AE data analysis, signals with repetitive frequency or with values too distant from the typical range of the damage source generation in these types of materials were discarded. Furthermore, the growth of the \(\beta_{t}\) toward values higher than 1.0 evidenced the instability of the damage process. The results of the localized procedure were detected just at the end of the monitoring and in correspondence of the critical values of \(b\)-value and \(\beta_{t}\). After this first monitoring activity, the AE cumulative numbers were also detected during the monitoring of the wood frame sustaining the tower bells positioned in the ancient cell of the tower. As observed in the case of the masonry structure, the \(b\)-value assumed values greater than 1.5, in correspondence of the first phase. After 11 days, the analysis results entered the critical band, in correspondence to the localization of the AE sources found for the wood beam sustaining the heavier bell. For the wood frame monitoring, the \(\beta t\) exponent showed an evident growth after 17 monitoring days. The \(b\)-value analyses were computed also at the seismic scale. The correlation between the structural behavior and the seismic activity was studied by comparing the \(b\)-value, obtained by AE signal detection on the structures of the tower, and the regional seismic activity. Concerning the correlation between the AE monitoring and regional seismic activity, a recent innovative analysis on different seismic sequences obtained surprising results. A new methodology able to discriminate foreshock and aftershocks earthquake time series was proposed. In the present paper, based on this approach, a correlation was obtained between the \(b\)-values computed by the seismic events recorded in the area near to the monitoring site (Turin), in a circular portion of territory with radius = 100 km around the tower. The first result of the present research regarded the confirmation that the analysis proposed by [PERSON] and [PERSON] (2019) [21] can be applied in seismic territory characterized by a low level of seismic magnitudes. The second evidence is related to the AE average \(b\)-values. Also, in this case, these variation trends were particularly evident for the considered periods. The average values of the AE \(b\)-value before the anticipant events are 1.05 and 1.42 for the two anticipating intervals, respectively. After the two anticipating events, the average AE \(b\)-values of 0.79 and 1.18 were observed for the two intervals before the main events. These two events were both anticipated by the previously mentioned series where the average \(b\)-values encountered reductions of 24% and 25%. The present study represents the first evidence that the AE average \(b\)-value analysis can be used, in addition to a seismic time series, as a robust parameter to discriminate between foreshock and aftershock intervals. Conceptualization, A.M.B. and D.M. ; Methodology, A.M.B. ; Software, D.M. ; Validation, A.M.B. ; Formal Analysis, A.C.; Investigation, A.M.B. ; Resources, A.M.B. ; Data Curation, A.M.B. ; Writing--Original Draft Preparation, A.M.B. ; Writing--Review and Editing, A.M.B. and A.C.; Visualization, D.M.