A Person's Voice

What is voice in literature? What writing devices are used to create it?
Voice is the specific way a person writes, whether by certain writing devices or through word choice. All of it goes together to form a person's voice.

Write a sentence or sentences about a topic of your choice. Then explain how that example reflects your own voice, What writing devices did you use?
"Nic Smith Vantas-Egbert is quite the odd child, as both of his parents are themselves odd and he reflects that. No, many paragraphs would have to be used to truly describe the way Nic is odd." This reflects my writing because I tend to be very self aware when I'm writing, mentioning specific writing devices, and I also try to make those reading it laugh.

According to the documentary, people in eastern Kentucky talk around a subject. Identify a topic you would talk around, and explain why you would handle the topic in that manner.
If I were asking for something I most likely talk around the subject. For most things, I really do not see myself as trying to talk around something, as I tend to bluntly say whatever I'm thinking.

Why is voice important in nonfiction? What are some things we normally avoid in academic essays?
People usually try to avoid first person pronouns, though "we" isn't that bad, it's "I" that people avoid, and they also try to be concise with their writing and not beat around the bush.

What are some ways we can develop our own voices?
The best way is to just keep writing. The you writing, the more your voice will develop.