If you do not have a planning permit for your location then you should have one.
Venue owners and the issuing authority have agreed in the permit to a number of issues that by law must be adhered to. Noise levels and hours of operation feature in all planning permits. Noise level requirements can vary as to terrain, altitude, proximity of housing, highways etc.
People can jump up and down as much as the like but nothing will change unless a fresh application with amendments is made and this is signed off by all.
MSNZ as far as I know do not own any circuits in New Zealand so really do not have a voice, but they do have to comply with the planning permits for the venues that their affiliated clubs conduct race meetings at.
There is a consistent noise level measurement method available.