This is perfectly normal. At least Harley thinks so. I have an 09 883 as well and I bought mine brand new. A few weeks after owning it and getting used to riding I had it back to the dealer about the engine noise. I hear my engine over my pipes. They looked it all over and said it was normal for it.
Then I went to another dealer (whom I trust) and the techie told me it was normal... Harley says it was normal. The techie believes that HD built the engine with more space in between valves or something like that and it causes more noise. Instead of Harley recalling all the engines back to fix them, they said it would not do harm to the engine and will change it on the next make.
So yes, your engine noise is normal. Even worse when it is hot and going up a hill.