We've found the males tend to mature around 8 to 9 months old......but it also depends on the weather. Trust me, you will KNOW if you have a male once he starts calling.

Pacman Mating Calls - YouTube

This is Pudding putting the moves on Jello.....they are our main breeders and the parents of ALL the froglets we have produced so far.
The call is VERY loud and reverberates throughout our house.........ALL night.........Especially during a rainy evening. The "Clicking" or "Popping" is usually a female trait. The females will make sounds, but nothing like the mating calls from the boys.