If you wanted to write the sound of a chuckle, you wouldn't write it "ha ha," would you? How about "heh heh heh?" Is it more than two or three syllables?
If you wanted to write the sound of a chuckle, you wouldn't write it "ha ha," would you? How about "heh heh heh?" Is it more than two or three syllables?
Since a 'chuckle' is a quiet or suppressed laugh, the actual sound would better be represented by a blank line.
I suspect that for chuckles, telling is better than trying to show :-(
AJ
I would probably describe it as a series of soft grunts.
There's no real reason to not use the word chuckle unless you specifically want to attempt some form of onomatopoeia and if that's your goal then you definitely should NOT use something like "ha" or "heh". These are historical/ cultural words that don't really represent the sound made, they've just been in use so long that most English speakers recognize them as indicating laughter.
I just watched a movie with closed caption turned on. Several times the closed caption said the character chuckled. I don't think the sound the actor made was the same any time.
I might just go with a single "Heh." Sounds like my own chuckles, at least when I'm not actually all that amused.