What accent is 'noice'?

From M-W - Where did noice come from?

One of the many ways in which dialects of English differ around the world is in the pronunciation of vowels. In standard American and British English, the long i vowel in words like shine, tide, or size is a diphthong—linguistics jargon for two vowel sounds joined in one syllable to form one speech sound—that is pronounced with the lips unrounded.

However, in some varieties of Australian English and New York English and in some dialects—such as Cockney English—the long i vowel begins with the lips rounded, in a position more similar to the vowel in words like short or lawn. Thus, the long i diphthong in these dialects sounds much like the diphthong in words like coin or joy.

The slangy noice originated out of such dialectal pronunciation for nice.

From my comments:

Where did noice come from?

One of the many ways in which dialects of English differ around the world is in the pronunciation of vowels. In standard American and British English, the long i vowel in words like shine, tide, or size is a diphthong—linguistics jargon for two vowel sounds joined in one syllable to form one speech sound—that is pronounced with the lips unrounded. However, in some varieties of Australian English and New York English and in some dialects—such as Cockney English—the long i vowel begins with the lips rounded, in a position more similar to the vowel in words like short or lawn. Thus, the long i diphthong in these dialects sounds much like the diphthong in words like coin or joy. The slangy noice originated out of such dialectal pronunciation for nice. - Merriam Webster

Noice (adj): /nɔɪs/

(Comparative: noicer, superlative: noicest)

(eye dialect, slang or humorous) nice

(It could be a blend of 'not' and 'nice' though that's not what it's used for.)

I have quite a few American friends and most of them use 'noice' a lot. I asked one of them who lives in the Midwest and they said:

Noice is like. . . a humorous way to say nice, but it always means "very nice," or "I'm impressed." It's New Jersey accent. It's how they speak. Maybe watch a movie with many boston or New Jersey accents like The Town. Rocky movies are close. they're new york accents (old New York).

oy is /oɪ/ in Australian, and /ɔɪ/ in RP.

So. The Australian pronunciation of why is /wɑɪ/, which is further back than RP /waɪ/. To RP ears, the closest diphthong is woy, /wɔɪ/.

But to Australian ears, why /ɑɪ/ and woy /woɪ/ are plenty different. So when they read “Woy it’s called Woy Woy Oy will never know”, they don’t think /ɑɪ/. They think /oɪ/. And Irish /ɔɪ/ is indeed closer to Australian woy than Australian why.

So you English are hearing a slight backing of the /a/ to /ɑ/ in Australian, and you’re mistaking it for the somewhat more drastic backing in Irish. And we Australians have no fricking idea what you’re talking about.

Oh the question was, why did it happen? Why does anything happen?

After the Great English Vowel Shift, long i was /əɪ/, similar to the value it has in Canadian English. Diphthongs can either narrow or widen. A narrowed diphthong has less difference between its first and second vowel: it is easier to pronounce (and the endpoint of narrowing is monophthongisation: it turning into a single vowel.) A widened diphthong has more difference between its first and second vowel: it is easier to understand, being more distinctive as a sound.

The development of Early Modern English /əɪ/ to RP /aɪ/ is a widening. The development of RP /aɪ/ to Australian and Irish /ɑi/ is more of a widening; and the development to Irish /ɔɪ/ is even more of a widening. Contrary to the stereotype of mumbled Australian English, keeping their mouths closed so that flies wouldn’t get in, in this instance Australian English is making more of an articulatory effort than RP, to make the long i sound more distinctive. (Quora)

I grew up in Australia then moved to Brooklyn ~3 years ago. I've heard "noice" repeatedly in Australia, but can't ever recall hearing it in Brooklyn.

As others have suggested, it's a facetious and emphatic way of saying "nice".

The "oi" phoneme seems generally more prevalent in Australian English, including people saying "oi" itself when Americans might say "hey!"; as a way of grabbing the attention of another person or an animal.

It's possible that it's actual origin is internet typos. O and I are adjacent on most keyboards, so very easy to type noice by hitting both keys at once while trying to type 'nice.' Much like saying "lawl" (pronouncing LOL) to suggest that something is funny (instead of actually laughing) has become more common, many words that primarily originated in TXT and forums make their way into common vernacular.

EDIT: Doing further digging, I think I may have invalidated my own answer. Now a sample of 1 isn't quite enough data points, but I did find a Lady's Magazine from the 1800s that used Noice, and elsewhere used "ax" instead of ask, so seemed to be trying to spell out the accents.

(Enter a cracker, his wife and daughter.) 'Who's the tapster here ?' 'I am, sir.' 'Have you any noice truck here for shirts ?' 'Yes sir, walk in, there's a nice piece.' 'What do you ax ?'

Further in, 'noice' is used several more times by the 'cracker' and 'foin' is also used which from context is likely intended to mean fine.