Sponsored Links
Speech Interference Levels - SIL - are the arithmetic average of sound pressure levels at the 500, 1000 and 2000 Hz center frequencies and is a measure of the degree to which background noise interferes with speech.

The diagram above indicates the SIL and distance at which a person would have talk in a normal, raised, very loud or shouting voice to be understood.
Sponsored Links
Sponsored Links
Engineering ToolBox - SketchUp Edition - enabled for use with the amazing, fun and free Google SketchUp.
© The Engineering ToolBox 2005
9 11 11