"but in smaller towns there is nobody to gather the evidence at 11pm"

.. you sure ?

.. You don't think there'd be local neighbourhood watch brigades of intelligence gathering 'concerned' citizens
on alert and at the ready with surreptitious smart phone cams
and noise measuring apps....???

let alone a network of internet sites plotting locations and time/date stamped noise measurements of 'offending'
nuisance pubs and functions...

21st century communications technology and grumpy old gits with too much spare time
will be a powerful force to reckon with....