Most of us recognize that English usage acceptable in conversation is not always acceptable in formal writing. By contrast, what is properly written is generally acceptable to the ear. This is not the case, however, with correct pronunciation, which is only an issue in speaking and never in writing, unless it affects one's spelling (and isn't that what spell check programs are for?! When mispronunciation does occur, perhaps it's a consequence of how we learned to read—phonetically or holistically—the pedagogical merits of which are still being debated by educators. More likely, however, is that we learned a word's pronunciation from someone else, who heard it spoken by someone else, and so on.
Moreover, this is one instance where regular reading won't correct the problem, unless of course you habitually look up the correct pronunciation of words in the dictionary.* If you open the pages of that most resourceful of books, you will find that there is an entire category of words that are so routinely mispronounced—even by radio and television journalists—that it's difficult to know their correct pronunciation.
The problem was made painfully evident in the last election, and exacerbated by the unusual delay of that process. Can you say "electoral"? The "-oral" words reveal a common problem of where to place the accent. If you look up "electoral," "temporal," "pastoral," and "doctoral," however, you'll discover that the accent is ALWAYS on the antepenult (that's the third syllable from the end—before both the ultima and the penultima; you may thank Latin for these terms). Except for "eLECtoral," all you need to remember is that the accent is on the first syllable of these "-oral" words: TEM-por-al, PAS-tor-al, DOC-tor-al.
Finally, I'm rather sorry the term is mentioned so frequently in public discourse, but if we must speak of "nuclear" weapons, then we should at least say it correctly: NU-cle-ar.
Why this concern about pronunciation? Am I just anal? Well, there's that, but it's also hard to ignore that the way we speak makes an impression on those we encounter. Consider that you want to make the best impression possible when applying for a job. Besides, word-of-mouth need not be a source of only misinformation; it can also be a source for improvement. You owe it to your future students—as I owe it to you—to speak as correctly as possible. And someday, if you undertake a DOC-tor-al exam, you'll surely want to say it correctly.
*Reading surely DOES improve writing. I think of this amazing sentence in the essay of one of my Western Civilization students, who clearly had not read enough: "Tiresome of the attacks, Assyria fought back with avenge ants."