To my ears, its sounds a bit like a laugh. Woodpeckers can also be identified by their characteristic drumming patterns. Drumming is simply a rapid series of taps on resonant wood that substitutes for song. With experience, patient listeners can learn to distinguish various woodpeckers just by their drumming, but this is definitely an advanced skill. A leisurely tapping sound often indicates a woodpecker in search of grubs and other insects.
Woodpeckers tap to find food much like a carpenter taps to locate a stud in a wall.
When it locates a fleshy grub beneath the surface of the wood, the woodpecker spears it with its tongue. The hard-tipped tongue has tiny barbs or bristles which grab the flesh of the prey so that it can be pulled back into the woodpecker's mouth when the tongue is retracted. Woodpeckers are also characterized by a curious arrangement of toes. Most woodpeckers also have four toes, but two face forward and two are directed to the rear. This probably helps woodpeckers hitch their way up tree trunks as they search for food.