10 Movies You Must Watch 1000 Times To Spot This

Steven Spielberg's Hook may be a deeply flawed film, but it's also surprisingly well-aged from a technical perspective and jam-packed with hidden details which elude even its most passionate defenders today.

And no sneaky detail is more unsettling than when Tootles (Arthur Malet) is woken up by the trusty canine Nana, who barks in an attempt to warn him that Hook (Dustin Hoffman) is coming.

When Tootles wakes up he immediately exclaims "Hook!," though if you listen extremely carefully to Nana's last three barks, there's something a little off about them.

Crank the sound up loud or watch the scene while wearing a good pair of headphones and you'll notice that we're not listening to a dog's bark but in fact a baritone human voice shouting, "Hook!"

It's an extremely clever and subtle effect, to the extent it's possible that Spielberg actually had the sound mixers combine a dog's bark with a human voice to create the sound, but to the casual, untrained ear, it just sounds like a dog barking.

If you're struggling to hear it, keep an ear out for the strong "k" at the end of each bark.