My frog made noises that sounded like a call (I looked up the sounds online). But mine certainly looks female now. I wouldn't say females couldn't make calls. For example, I have a female canary I bought as a male a few years ago. The breeder thought it was male, it certainly SANG like a male (and everyone will tell you females don't sing!). It wasn't until she started trying to make a nest and laid eggs that I knew for sure...Frogs could do that same thing...