In The Night Garden - didn't the HaaHoos used to be HaaBoos?

[lagaanisace]

Is it just my imagination? I hope this is not to taboo for MN! Is it just one of those things that nobody mentions?

[Bucharest]

I think they've always been Haahoos but most children (like my dd) and consequently, their parents, who are dozing off on the sofa while it's all going on, think they are harboos.