I totally disagree on it being normal for them to sneeze in a new home. No it's not normal although sometimes there is an irritant in the new home that can cause it. Frequent sneezing is always something to take seriously especially since you've had him home a week and he only started sneezing a day ago. If it was an irritant in the new home, it should have happened the first day or two.
When he makes these noises, what is he doing? Are his quills up and does he sometimes make a little jump, like a pop? If so, it may not be sneezing but an angry noise.
Does he lick his nose frequently? If so, his nose might be runny and you won't notice because he licks it off. Nose licking is normal as they explore, but excessive nose licking usually indicates a runny nose or something irritating it.
What type of bedding do you use? If a loose type of bedding such as shavings or Carefresh, put him on liners. A temporary liner can be a pillow case or go buy some polar fleece and cut to fit the cage.
If it is sneezing, he needs to see the vet as respiratory infections can go downhill quickly.