Does quack always mean hen?

[strutt20]

I have my first two 8 week old ducks. Two either mallards or rouens from TSC. I am almost 100% sure one is a drake. He is very quiet and barely peeps loud enough to hear. Plus he has the start of a drake feather. His counterpart has the exact same coloring up until this point and same size. However it quacks. Quiet at times and VERY loud at other times. My question is does this mean with out any doubts that I was able to pick out 1 drake and 1 hen out of the tub by chance? Please weigh in and let me know

 

[Amiga]

There are anomalies in feather coloring, and every now and then with voice, especially early on.

So I would not 100% guarantee, but it is looking like you have a duck(female) and a drake.

 

[strutt20]

Thanks. I have read of vent sexing, voice sexing and then feathers when they come in. Just didn't know if the voice was full proof. I have even read that the drakes that even do make a noise that sounds like a quack that it is never loud. Something about their vocal chords being different where they don't have the vocal range as the females.