voice has two different meanings, 1' the sounds which generate from the mouth, 2. voiced and voiceless sounds which are related to vocal codes. If you men the 1st one the answer is "not at all' the reason is pronounciation can be different from writing. As well as similar pronounciations but different spelling. we have to think a lot of things when writing.
voice as the critical views we use in our academic writings is vital; otherwise, our text is a collection of other researchers' views. regarding discussion and conclusion, I try to evaluate the case critically and add my view.
In my view, voice is different from writing. Manner of writing is not depending on the voice. e.g. The pronunciation of 'are' is [a:] . Voice is related to the pronunciation.