Cockatiels will copy each other's songs. My rescue cockatiels come with their own songs. By putting them together they copy each other and sometimes sing the same song at the same time.
If a male cockatiel is healthy and well cared for he will start singing around 4 months. That is when the flock stops feeding him.
I don't know if listening to another cockatiel would bother him or not. I know cockatiels call each other to join their flock. I moved here about a month again and my neighbor has cockatiels. Mine call back and forth with them all day trying to call them to the flock.







