Knowledgeable, intellectual, intelligent, informative - these all describe the scientific voice. This voice shares knowledge, studies, findings, and it does so in a way that even though it may be challenging, we at least try to understand. Most of the time.
A sceintific voice is often a respected one, however, it can also bring distrust. It's expert in its field, whether in a fictional setting or relaying real world information. However, with its expertise can come disillusionment, so though we often think a scientific voice is a fount of knowledge, there are often the naysayers who don't believe a word of the scientist. It's a controversial voice, especailly right now, but this can add to its effectiveness in your voiceovers.
A scientific voice is great way to present information or narrate a documenetary. It's also perfect to add depth and characterization to a fictional character, whether in a videogame, audiobook, or voice over film. Depending on what your goal is, how you depict the voice, and how effective you are in doing so, your audience could up loving or hating this science guy - it's up to you!
First off, we all kow the scientific voice will be filled with jargon. Scientific jargon. So will we understand everything? Maybe, maybe not. The voice will have that intellectual note, which may or may not sound a little condescending, depending on delivery. Because scientists talk with other scientists, they may not always clearly convey their ideas to the "general public." This can be great for character development.
Depending on your needs, you can have a realistic scientific voice, like for a documentary or scientific read. Or you can have a mad scientist or neurotic one; we've all seen Phineas and Ferb and Dr. Doofenshmirtz. Enough said.