Rail noise measurement is an art in itself - one that we have been developing for nearly three years now. This post provides some information on what we have found.  It is not pretty.  It might help you understand this if you don't know about decibles and Equivalent Noise level to look at our common questions by clicking here or by clicking on the tab at the top of the page.  If it is not covered submit a question and we will try to answer it.

• Here is a graph which summarises some of those measurements. The gaps are when we did not collect continuous data