[ninenot]

In most of the cases where you used the vowel "a" (Froid-a) we use the schweh (in the dictionary, an upside-down small letter E.)

So the pronunciation is a bit more like Froi-deh, as opposed to Froi-dah.

The schweh results in a better choral tone/sound, and is clearer to the listener.

[Michael81Dus]

I was just telling you how I imagine you write our words to pronounce it correct. :-)