Hi Graham
I am not sure about the Veritas 8 but the panels we install all have adjustable sounder volumes inside the panel so you can set accordingly and are silent for nightime setting.
Chances are the engineering code will have been changed by the installer at time of installation - the original is hardly left as default to prevent unauthorised access.
Hope this helps
Any further questions feel free to contact me directly at:
mail(at)alcosecurity.co.uk
Regards
Alex
October 2010