hiccups is just basically your diaphragm twitching. So of course when baby gets them, they don't make any noise. Because when we get them the sound you hear is the air passing quickly through your throat.
sorry, I like being technical, stupid habit.
I'm not sure if my baby gets hiccups, but baby sure likes to change positions A LOT. There was a 2 minute period one day where I swore baby was doing jumping jacks, but the doc said it's just changing positions, that's why it was so hard for her to find the heart beat