Sounds like you may have some post-nasal drip, or may simply have
noticed the small amount of fluid that usually pools in the posterior
oropharynx when you lie down. Other than being aware of it, it doesn't
appear to be causing you any problems, so I'm not sure I'd call it a
"condition".

Hey , have you found anything out about this yet?

I've just found your question about throat noises after doing a search on the
Internet about this. I'm up late (for me) since I can't sleep because of all
the noise going on in my head. I can't figure out if it's throat or sinuses
or ears or if I'm losing my mind.

It started out with a cold trying to get the best of me. I woke up in the
morning with a little "purr" in my throat and it's gotten progressively worse.
Tonight is the worst it's gotten. My husband can even hear it as he lies next
to me.

I sure hope you've found something out.