What is the best way to train listening? Watching TV, listening to songs, watching movies, talking to natives?

When I was talking to a native australian I understood him absolutely well, but then he phoned his friend and I was unable to understand anything. "bvkjnl;kfnm3nfpifjdapifpoasjdoasjdfpjqwpdfjpqojfo iwqjfdpoiqwjdfp"

I recognized only few words.

That sucks.