Hi,
Experiencing quite an interesting repeating error with GPT-4 Voice.
GPT-4 Voice during 3 chats now at some point thinks I have spoken Welsh, I am Scottish, responds in Welsh, ends chat with GPT-4 and switches to GPT-3.5 after around 15 prompts. I cannot continue the conversation with GPT-3.5 in textbox when this occurs.
Regards
HoLAI
I have experienced this issue frequently using the Whisper API where my English audio input is transcribed and then translated to Welsh.
I have also found it happening more recently with ChatGPT exactly as OP has described it. Using ChatGPT 4, speaking in English (with an English accent) when a random Welsh sentence which when transalted bears very little resemblance to what I have said is inserted into the conversation and the AI then switches to GPT 3.5 and starts replying in Welsh. I then protest ‘I am speaking English, I do not speak Welsh, please Reply in English’ and the response will then continue in English, however during a rather lengthy chat today this happened 3 times in total. Interestingly when I protested the last time my last protest (where I clearly said I do not speal Welsh. ‘I dont know why you keep speaking Welsh, I speak English and only English’ which was .transcribed and converted to welsh and when translated back to English as ‘I don’t know why you reply in Welsh. I speak Welsh and only in Welsh’ which is very curious.
A few thoughts…does this primarily affect those speaking English with an accent from the UK? Have there been any reports of chats switching to Scots or Scottish Gaelic or irish Gaelic or Cornish or other official UK languages…or just Welsh?
It seems to me this is too much of a common occurrence for it to be a quirk based on a misheard word. Surely far more users would be reporting their chats switching to Spanish or French as these languages are far more widely spoken. Seems like some sort of config issue with how welsh is configured - perhaps set up as a dialect or subset of English-GB or something bizarre?
Happy to provide more info if it helps
I have not had the issue since. However I have seen others having it. It can still misinterpret me sometimes.
This is still happening to me. I get a response in Welsh, and when I go back and look at the chat history, my words have been translated into Welsh. I have to prompt it to say that if it thinks I’m speaking Welsh, to translate my question into English, and then respond in English. I’m in Scotland, speaking with an English (Midlands) accent.
Brand new user here and it just happened to me. I am also from the Midlands!
Happening to me today too - using voice to test the capabilities of GPT 4o and it provided an answer to my question (spoken in english) about game theory in welsh!
Same here. Keeps reverting to Welsh. It apologises when I tell it and 5 mins later it’s at it again. Have language set to English not auto but still the same.
It happens to me. I’m from Sheffield but not got a strong Northern accent. Also happens to my brother, wife and local friends.
It happens so often I’m considering asking it to teach me Welsh. 
In the custom instructions I have said very clearly that I am not Welsh, I never speak Welsh I can only speak UK English. … but still the Welsh comes, probably daily.
Just tried GPT-4o with the new audio feature and getting the same issue.
The entire audio conversation is in English but when reading the transcript back some of my sentences have been translated to Welsh. All the AIs responses are in English.
I have an English accent too; perhaps you have to add a US “whine” to avoid Welsh being thrown out.
Fix: if u r in the ChatGPT App go to Settings-> “Main Language”, set to English (mine was set to ‘guess’ or similar); Settings->App Language” to English
