Sound levels outside Simon - could I suggest you refer to slides 36 and 43 in my presentation - these relate to external sound levels at Duffield and Belper after sound control was installed. In particular, Belper has the nickname "The Peal Factory" and houses are situated within 50 metres of the tower. It is nearly impossible to hear the bells when the sound control system is closed. I should point out that any system must be 100% airtight when the doors are closed as is the case at Belper. In my experience most people do not understand what "airtight" means and approach sound control with a "that should be alright" attitude which never works!