What happens when you call a fax number?

If you were to call a fax number with a regular phone, a fax machine would answer and you would hear a series of beeps.

The beeps are the noise of the fax machine sending a signal to say “there is a fax machine here.” If no fax machine on your end of the phone line beeps back at the fax machine, the receiving fax machine will simply hang up the line.