I also studied voice and did free-lance voice-overs for a number of years. In my college speech class, we had to read various things out loud. I read a story about a grocer selling in his market. When I finished, the professor said she could hear the smile in my voice. If you want to "put a smile" in your voice, it helps to actually smile when speaking.When I was taking a voice actor radio training class the instructor said "put a smile in your voice ". That was good advice. I ended up doing quite a bit of narration of medical training videos, for the U of T schools of medicine. My in was my Wife who was the business manager for one of the schools. JimB. In Toronto.