Dogs get hiccups for a variety of reasons including eating too fast (common with dogs, especially puppies), stress, excitement, or even hypothermia. If the hiccups are not lasting for very long (you don't really indicate how long, so I'm assuming they're short-lived) then I wouldn't be concerned even if they're a little funny, humans can have funny hiccups too. At any rate, puppies are more prone to hiccups than full-grown dogs, so you should see a reduction as he gets older and maybe even a smoothing out.
If you are a little concerned still and want to help, you can always give him some water or massage his chest to help loosen and relax his diaphragm muscles. If the hiccups do go on for an extended period of time, then taking him in to see a vet is a good idea.
Some good detail on doggy hiccups can be found on Vetinfo.