In this approach, a Testing-Set will include the data-sets from one phone during an experiment, and data-sets from all the others form Training-Set and we repeat the process for each phone. For instance, the 8 blast event data-sets sensed by Phone P1 during Experiment E1 will form a Testing-Set-1 (as seen in Table IV), while the 8 blast event data-sets sensed by Phone P2 from same experiment (EI) along with data-sets from all the phones in E2, E3 and E4 results in a total of 44 data-sets which will form a Training-Set. This process is repeated for all phones, and as such, we have a total of 14 Testing-Sets to build and test the model as shown in Table IV.