Indeed, males usually tend to be noisier than females! Not always, but it's the general rule!
Males usually tend to whistle and be quite vocal, singing away, having various chirps, and doing heart wings. Here's some ideas of what 'heart wings' looks like!
Females on the other hand tend to have 2-3 chirps and that's about it. There are other ways of trying to sex cockatiels but this only works on mature birds (a year or older), and does not always work with pieds.