PASS Audibility Project

This part of the study comes from the DT (Detection Threshold) term in the passive sonar equation. This term relates to the receiver of the system; in this case, the receiver is the firefighter. 

 

Firefighters wear a specialized set of personal protective equipment (PPE) when they respond to building fires. This set of PPE includes helmet, hood, coat, gloves, overalls, boots, and self-contained breathing apparatus (SCBA). This study focuses on how the helmet, hood, coat, and SCBA change the sound that reaches the ear of the firefighter.

 

To understand this, two studies were conducted -- one physical acoustics study, one audiology study. The physical acoustics study helped us to understand which pieces of equipment influenced the signal the most and how exactly that influence manifested itself in the physical signal. What it lacked was a way to understand how these changes in the signal influenced the firefighter. For this, the audiology study was conducted.