Hi,
You might want to read this link and perhaps it will give you a hint of what you are hearing.
I always called reverse sneezing "snorting" because it sounded that way to me. I had a chi that would do that when she got excited.
I don't know what you're hearing.
Some get tonsillitis, but that is more of a coughing and would continue to get worse as the days passed, so you probably don't have that.
Let us know if you figure it out.
http://www.earthsangels.com/html/coltrach.shtml