This is just a very dull-marked White-browed Scrubwren, possibly an immature. It is possible that you might see Large-billed or Yellow-throated Scrubwrens which are quite different (Large-billed is a plain brown with larger bill and black eye and Yellow throated has a yellow throat). These 2 species only occur along the coast and would be at the inland extent of their range where you are - however I've seen both at nearby Monga National Park.
Thank you. I was confused, as these birds sounded like scrub wrens, but didn't have the 'angry face' markings. I'm about to post photos of a similar bird (in sound) but the red on the beak intrigues me.