Bit of a strange, and very specific, question.

In Sandman, Fiddlers Green uses the exclamation “Hoom” a lot.

I've been reading The Two Towers for the first time and noticed that Tolkien also has Treebeard using “Hoom”. I know Tolkien was familiar with Chesterton's work, and it got me thinking.

Did you have Fiddlers Green saying Hoom because it was something Chesterton was known to say a lot?

If so, do you think Treebeard says it because Tolkien is paying tribute to Chesterton?

Or was it just something common in the circles both Tolkien and Chesterton moved?

Thanks!