It's quite possible that the noise you are hearing is just interference from the many consumer devices in your house as well as others.
As scanners are extremely wide band recievers they are very sensitive and will pick up things that aren't really there (or supposed to be there).
Computers are a good example, if you use your scanner near the computer and attempt to listen to just about anything in the VHF bands you will come across quite a lot of interference on random frequencies.
Here's a link that you might find useful.
http://web.acma.gov.au/pls/radcom/regis ... .main_page
That is the ACMA radio comms database. You can search for just about anything. Next time you hear something on a frequency and you want to know what it is, change the dropdown box to "Registrations" then the next one over to "Frequency (mhz)" and then type the frequency in the search field and press go.
Another cool thing you can do is search by postcode, so you can stick in 6230 and then it will take you through everything that is registered in your area.
P.S I used to live in Somerville drive so that's why I know the area so well

I'm in Perth now.