**5.2. Loudness**

The information about total occupying area is also related to determine the loudness of an alert, and hence, the number of effective mass notification units required to a particular area. The loudness of sound from all types of siren is subject to diminishing ten decibels at every doubling of distance between the siren and point of measurement.

Since the occupying area information shows that area of each pilot community lies within 0.1– 3 sq.km range, single mass notification unit (for each community) with sound intensity of 120– 130 dbs can give enough loud sound to cover the whole area for example similar to INMARSAT System currently installed in Gwadar and Pasni cities.
