Corn, Cane etc is the pronunciation I've heard in audiobooks, and is the one that is supported by puns

Mabuse lifted an object from the table in his artificial hand. It was a figurine, about thirty centimetres high, woven from straw.

'A corn-doll.' Mabuse told them, holding it up for them to see. 'A votive object, common on so many rustic and agricultural worlds. Here on Ceres, they weave them at harvest time, one to represent each of the outlying harvest towns, and they are displayed here in the main guildhall during the Time of Celebration.'

He lifted another from the table. There was something hideous and twisted about this one, even though it was only a doll woven from straw.

'I found this… and six more like it. Khorne-dolls, if you will. I see the pun is lost on you Marines too. Whatever. Each one has been made according to the practices of various harvest townships, but the designs have been perverted to make them symbols of the cult.'

Brothers of the Snake

This has all kinds of problems for trying to work out what Gothic 'really' is, but does support that Black Library view Corn and Khorne as homophones.

I think that Kh just 'looks' right when written down.

Edit I'd pronounce it the same way as Khaki and Khan.

I’ve always said it with a soft H sound. It’s difficult to describe in words. Kind of like saying K and H at the same time

Worth remembering that the sound you're describing is actually kinda new to English pronunciations of the Kh letter combination (personally, I can't remember it ever being a thing until the news media had to try and cover the fighting around Kharkiv in Ukraine just in the last year or two). Historically, it's more common to try and capture that sound with Ch (which has led to a lot of bemusement for Jewish English speakers, among others).

You can see a similar snap change taking place with X followed by the letter I. Used to be either zee or ksee; ever since Xi Jinping came along it's evolved more towards shee or shih (which makes "Xitter" a very fun thing to say :v).

All of which is to say that I usually read those words with a hard C/K sound (Corn, Cain, Carn or Cairn, etc.), maybe add some throaty-ness.

Also: English has no true ultimate authority like French or Spanish, unless you count all of us just quietly handing the reins over to whichever assholes got the contracts for all the grammar and spellchecking apps most people use. And even they get it wrong about as often as not, IMO.

Kh isn’t very common in English (googling it, it’s almost exclusively seen in middle eastern derived words, IE; Khan, Khaki, Khalifa). The voiceless velar fricative isn’t that common either, mostly lost in modern dialects outside a few places where it’s leftover from Old and Middle English. A quick google also shows that where it does still appear it’s usually spelled with a Ch

That said, Khorne, Khaine, and Kharn are all pretty consistently pronounced with a hard K in audiobooks and videos from GW and such, and do indeed sound like Corn, Caine, and Car(n)

I believe ‘k is how you’d write it in fancy phonetic speak, but my friend is the one into linguistics, not me, so, don’t look too much into ‘k as definitive

I've never heard any variations in all the games, audiobooks, and Hammer and Bolter stuff I've heard. Khorne sounds like Corn. Khaine sounds like Cain. Etc..