Cat Stopped Meowing Normally?

I have a four year old male cat named Angel. Recently, within the last two months, I rescued a four moth old male kitten. Angel likes him and plays with him. About two days ago both of them were playing and my kitten accidentally kicked my Angel boy in his throat and since then he has not meowed like normal.

I called many different vets in my town and they are all telling me just to watch him and make sure he eats, plays, and goes to the potty box. I have been, and so far so good. However none of the vets are telling me what this could be. I just want to know my baby will be okay seeing how the vets in my town won't even give me an appointment. Has anyone ever had this problem or a similar one? Any info anyone can give me would be gratefully appreciated.