What is the expected sound pressure level loss at a listener 15 meters from a presenter, given that listener 1 is 2 meters away?

The expected sound pressure level loss can be calculated using the inverse square law, which states that sound intensity decreases with the square of the distance from the source. Specifically, sound pressure level (SPL) in decibels decreases by approximately 6 dB for every doubling of distance from the sound source.

In this scenario, we start with a listener positioned 2 meters away from a presenter. Moving to a listener located 15 meters away means we're observing a change in distance from 2 meters to 15 meters. To find the total increase in distance, we can look at how many times the distance doubles as we go from 2 meters to 15 meters:

1. Doubling the distance from 2 to 4 meters results in a decrease of 6 dB.

2. Doubling the distance from 4 to 8 meters results in a decrease of another 6 dB.

3. Doubling the distance from 8 to 16 meters (the next doubling after 8) results in a decrease of another 6 dB.

Since the listener is at 15 meters, we don't quite reach the 16 meters, but we can approximate that the SPL loss is close to that of having reached that distance. So