Hiccup/coughing/puffing?

[Levaethan]

The only way to describe the sound my 9 month old female makes is like the sound an inhaler (like the one used for asthma) makes when you depress the plunger.. A quick burst of air combined with a brief puffing of the beard... Its like she has something stuck in her throat but ive looked in her mouth and i dont see anything... she has a very healthy appetite, no blackening of the beard, no mucus coming from the nose or mouth... Temps in the cage are perfect in the hot and cool zone, dust free play sand mixed with a bit of calcium sand, poop and old food are taken out the very same day if not the next.... She does this ALOT... sometimes once or twice in the span of a couple mins. I have no idea what she is doing, and although ive been told it could just be her "quirk" and not to worry... I am worried... I have 9 beardies in total, and she is the only one who has ever done this.... HELP!

[ladyknite]

dust free play sand mixed with a bit of calcium sand

there's really no such thing as "dust free" sand.  And calcium sand is ........in a word..........dangerous

Based on the information you've given it sounds as if her environment is creating a respiratory distress issue for her that may come and go......until one day it comes to stay.  Similar to the way an asthma attack can turn into pneumonia at the drop of a hat.  I'd change out her substrate to a non particle and test out the theory.  If it works, you know her respiratory system couldn't deal with the amount of dust and particles.  If it doesn't work, we can move onto something else.  Easiest first.