I recently finished this area of the game. Acornia is mentioning the room across the valley that has the audible sounds made by the prayer grinders. I did this on my own and got lucky. Here's what I did.
1) go across valley in tram and listen to all the grinders.
2) come back and enter the temple.
3) follow the walkway all around to the other side and to the end.
4) walk across the narrow wooden walkway over the water and past the statue.
5) enter the room with prayer grinders.
6) click on each grinder and note the shape of the grinders that make noise and the color beneath
7) click on these 3 grinders and change the color of one each time using one of the colors from the others that made noise.
It will take a few tries but you should hit upon the correct colors that go with each grinder. Note that the order they are clicked on is important and not necessarily L to R or R to L.
This is hit or miss but I couldn't for the life of me understand the priest anyway. I was able to keep walking across the path and listening to him each time by clicking on a prayer that made noise and walking back. Finally got tired of trying to understand him
Sorry I went on, but I hope this helps a bit.