May you explain to me what this sentence means?
"Calling out across the line". This is a part of a song. I tried to understand it translating it, but for me It has no sense.
Please, if you know English and Portuguese explain it to me, or if you speak only English, try to explain it using different words.

The song says:

All the voices in my mind
"Calling out across the line"

Thank you very much.

Question

May you explain to me what this sentence means?
"Calling out across the line". This is a part of a song. I tried to understand it translating it, but for me It has no sense. 
Please, if you know English and Portuguese explain it to me, or if you speak only English, try to explain it using different words.

The song says:

All the voices in my mind
"Calling out across the line"

Thank you very much.

Answer

I think it is an invisible line, like a limitation she/he has put up in her/his head. It might also be two different sides of her/himself.

Answer

It could also be a reference to the telephone, which used to be called a line. Then came the slang "Drop me a line" which means to "Call me". Over time "Drop me a line" Has come to mean any form of communication(Phone, text, ect) So its just saying they are calling out from somewhere else ^^