"The machine in the picture can generate a Sound Pressure Level of 165 dB from an air supply at 120 psi. The air is modulated by a servo-driven reciprocating poppet valve that sounds as though it is the direct descendant of Parson's comb-valve.
To put this in perspective, 130 dB SPL causes instant hearing damage. About the only thing in the world that generates such extreme levels as 165 dB is a rocket engine at close quarters- and that is exactly what these noise generators are used for- testing rockets and jet aircraft to make sure they can withstand the noise of their own engines".
Your next purchase rick?
http://www.dself.dsl.pipex.com/MUSEUM/C ... xetoph.htm
