AG1086A Concept Development: DB Chart of Human Hearing

This infromation will help me effectivly place the correct sounds at the corect
frequency range in my soundscape. Also with these pictures it shows all the
frequency range and decibel levels of a humans hearing on an average day.

 http://www.deafchildworldwide.info/childhood_deafness/what_is_sound.html

http://www.marineenginedigest.com/gensets/portable.htm