I have been asked many times over the years about whether the judge will use a gavel. Actually, most of the time I'm not asked about gavels, but about the judge's hammer, because this is after all what the gavel is: the stamp of the judge's authority.
Well the best answer is probably the easiest. Someone, somewhere may use gavels in the courtroom in Australia. At best their use is rare. It's just that in almost 25 years of going to various courts including the High Court, Family Court in Brisbane, Townsville and Sydney, I have never seen the gavel in court, let alone being used there.