As I replay this I see that its come out a lot quieter than how it actually was. However this will give you a sense of the type of noise.Instead of 30 seconds of it, we have 8 hours of this forced into our homes.Click on "MORE FROM THIS USER" to listen to other examples of this noise, which the Christchurch City Council deems acceptable .
To get a rough idea of what this is like - turn it up so that no matter where you go in your house you can still hear it. (less info)