What is the difference between おう　and おお, pronunciation wise?

oh-u, ohhh ???? context!?

Pretty sure there isn't one. They're both a long 「お」 sound.

Mcjon01 Wrote:Pretty sure there isn't one. They're both a long 「お」 sound.

I'll just stick by that one, and blame you if there's any problem

As far as I know, おお is the older way of writing it and has retained with a few words. (Though this may be wrong)

There is a slight hook on the end of 'ou' where there is none on 'oo.' They do sound very similar, but I assure you that they are not the same. It's very similar to english in this way, but not quite as severe.

The beginning of おおかみ sounds different from the end of こくおう.

ohh-kommy vs. koe-koo-oh-uh, but that last bit on こくおう shouldn't be emphasized quite the same amount as the rest of the word. It's a subtle thing.

Yeah. Erlog's right. At the beginning of a word, (ookami) your mouth just remains open but stationary for longer. In the second word (kokuou) there is a very slight and certainly incomplete closure of the mouth, almost but not quite an "oo" with a wisp of breath escaping as you shut down the word. As Erlog says, it is a subtle thing.

As i say those words i say "oh" but think "oh-oo" and somehow it comes out right (I've been told).

(Sorry for the romaji. )

It's not really worth thinking about.

The long o sound is almost identical in words like 王子 (ouji , prince) and 狼 (ookami , wolf).

おお is used so seldomly that you can simply learn all words which use it and use おう in all other situations.

Well there is also とお と　とう and their other friends. This is is why I asked.

Of course there is difference! And a big one! Of course is worth thinking about!

But it is simple to learn, just pay more attention.
It is not like pitch accent wich doesn't show up in the hiragana.

I really dispute this idea that there's a difference (in sound) between おお and おう. おう is pronounced オー instead of オウ; it's just one of those rare exceptions to the Japanese spelling system. Presumably there was once a difference between them, and this distinction might still be maintained in some dialects, but it's not standard Japanese.
If they're *not* the same it's a bit of a mystery, since Japanese people certainly think they are and can even have trouble confusing them when writing (here's a page about the issue: <http://homepage1.nifty.com/forty-sixer/tyouon.htm>).
You can google "発音 おお おう" (or English equivalent) for a lot of sources to back up the claim that they're the same; can anybody find a credible source that disagrees?
Now, people will certainly pronounce オウ when they're conciously trying to point out the spelling or avoid ambiguity with a word spelled with おお, but that's an affected pronunciation, not their natural one.

To make somewhat of a comparison, this question is like asking a native English speaker if there is a difference between the vowel sounds of words like "boar", "lore", and "your"? Almost everybody would agree that these words rhyme, but you will get at least a few people who will claim that there is a subtle difference in the vowel pronunciations. For example, some English speakers may actually prounounce a slight dip in the word "your" to enunciate the shift from "o" to "u". This is usually done by the same people who got "A's" on spelling quizzes when growing up. The difference is very subtle but it can exist, in an arguably purely optional way. Many people really don't distinguish the differences at all, but ironically, "your" is often said closer to "yer" in informal speech which probably has more to with laziness than any kind of spelling "interpretation".

Therefore, even though I haven't used Japanese examples, I don't think there is an absolute answer to this question because everyone has different ideas on what is proper in pronunciation.

As snallygaster, it's an orthographic issue. Same with えい/ええ. 平気 (へいき) is the same as お姉さん(おねえさん). It just gets perceived differently sometimes because we try to map what we see in writing to what we hear. But it's all the same.

Eeeexcept when it's not. Sometimes an おう CAN be the two different vowel sounds instead of a long vowel. Basically, this means verbs. 思う. But that's kind of patent.

mentat_kgs Wrote:Of course there is difference! And a big one! Of course is worth thinking about!

Nonsense. As QuackingShoe pointed out. The only time -oう is pronounced differently from -oお is across morphemic boundaries.