Definition of "hah"

Shut up, buddy, you've forgotten that I can't run. Now you're the wise guy, hah?

1994, Milton Teichman, Sharon Leder, Truth and Lamentation: Stories and Poems on the Holocaust, page 58

Isaac Sachs makes a 'Hah?' noise. 'You're not Sixsmith's niece?'

2004, David Mitchell, Cloud Atlas, London: Hodder and Stoughton