It’s the Moaning Tree Frog! 

Heleioporus eyrei has an unmistakable call, but the frog itself is nearly indistinguishable from related species in South West Australia, several of which occur in the same place. This frog species appears to be able to persist in suburbia, and calls from backyards near the centre of Perth.

Winner: 

Thanks to the team at the Australian Museum's Frog Id project run by Dr Jodi Rowley