We all should agree that there's a general call. That's when the gospel is proclaimed.
But the effectual call is what the sheep hear. Evidence of this is in John 10 when Jesus talks about His sheep hearing His voice, and the Pharisees not believing because they aren't His sheep. The parable of the sower and seeds bears this out because only the soil prepared bore fruit.
But the clearest picture is Romans 8:30. We see that those who are predestined to be confirmed to the image of Christ are the only ones called in an effective way. We know this because it says that those who are called are justified. If the "called" in Romans 8:30 referred to all of those who hear the gospel, then everyone who heard the gospel would be saved because they would be justified.