Master slideSlideDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingEqual-loudness contours (red) (from ISO 226 :2003 revision)DrawingDrawing10Drawing-10Drawing10Drawing100Drawing1000Drawing10kDrawing100kDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingSound Pressure Level (dB SPL)Drawing(threshold)Drawing0Drawing20Drawing30Drawing40Drawing50Drawing60Drawing70Drawing80Drawing90Drawing100Drawing110Drawing120Drawing130DrawingDrawingDrawingDrawing40Drawing80Drawing60Drawing100 phonDrawingDrawingDrawing20DrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawingDrawing(estimated)DrawingDrawingDrawingOriginal ISO standard shown (blue) for 40-phons