When I was holding a female cockatiel at an aviary, she was making funny little noises. The lady in charge said that it's the same noise that they make when they get hand fed and, that when they're older they do it to get attention. I don't know if male and female do it but I thought this might help. I'll be able to ask the lady on Monday, I'm sure she would know.
My Georgie when she was younger use to do that alot when we gave her scratches now that she is older she doesn't do it anymore, Ollie never did it and Minnie only did the begging for food cry when we touched her now she is quiet for head scratches. I think there all different when it comes to noises there is no sure fire male/female way to tell some males make alot of noise and some are quiet and vice versa.