My cat's meow has changed to a squeak

Peeks is 5. She's indoor only and about two weeks ago I noticed when she went to meow sometimes, it was just a little squeak. She's a big talker, so it hasn't stopped her, but her voice is normally a deep gurgle. It's mostly at the beginning of a conversation and along the way she seems to find her old voice. I took her to the vet, he looked down her throat and felt her neck and there were no abnormalities. He gave her some antibiotics and they seemed to help a tiny bit in her being able to find her voice more quickly, but she's still squeaky like crazy. We've been waiting it out, but the doctor said we should see improvement in 3 days. It's been 7. Any ideas? She's fit, happy, and normal, no signs of illness. I just hate to stress her out and haul her to the vet when he doesn't seem to know what's wrong either. 

Believe it or not, there are several threads similar to yours.  And never anything wrong with the cats

So...I'd say since you're been to the Vet and had her thoroughly examined, not to worry.  either she'll get back to her normal meow at some point, or this is her new voice.  You know cat's really only talk because WE do.     Maybe she's changed her way of talking because YOU have

Do want to add- it took a while but she got her voice back but I did give her the antibiotics as told even though I'm not sure they did much. Glad to hear it's commonly nothing!