Door lock - twang noise

I have an odd noise from my passenger door lock whan it locks/unlocks on the central locking - a kind of 'twang' that goes on for a second or two.

It's obviously something to do with the actuator, but any specific ideas/thoughts?

Does it sound like metal twanging metal?

Sounds like a comedy spring noise - boi-oi-oi-oi-ing.

Lol oh dear...

I replaced a door lock and had something "twanging" turned out to be the rod that the lock button on the door is attached to rattling. off came the card fitted a new clip Twang gone lol. Try pushing against the door card when you lock the door to see if its something thats lose.