UI language vs transcription language on iPhone: what’s the difference?

It is a reasonable assumption to make: the phone is set to a language, so anything the phone does with your voice should use that language too. It is also wrong, and worth understanding why, because it is the kind of mismatch that shows up as "why is my transcript in the wrong language" rather than as anything that looks like a settings problem.

iOS itself treats these as two different questions

A phone’s system language — set under Settings → General → Language & Region — decides what script and wording iOS and its apps display. Speech recognition is a separate system, with its own separate language list, because listening for a language and displaying text in one are not the same job. Apple keeps them apart even in its own apps: the keyboard’s dictation languages are configured on their own screen, independent of the phone’s display language. Any app built on Apple’s Speech framework inherits that same split, whether or not the app’s own settings menu makes it obvious.

What UI language actually controls

This is just the text you read on screen: button labels, menu names, the words in a settings screen. It comes from a fixed set of translations the app’s developer has written and shipped — an app can only display in a language it has actually been localised into, not in every language a phone can be set to. Voice Studio ships 19 UI languages; set an iPhone to one of them and the app’s own screens follow along. Set it to one outside that list, and the interface falls back to whichever language the app treats as its default, the same way most localised apps behave.

What transcription language actually controls

This is a separate choice: which language Apple’s speech recognizer should listen for when it turns a recording into text. It is picked on its own, independent of whatever language the screen around it happens to be written in, because the audio itself does not know what language the app’s menus are in — the recognizer needs to be told what to listen for. Voice Studio supports 38 transcription locales, chosen through the app’s own setting rather than inherited from anywhere else.

Why the transcription list is bigger than the UI list

Translating a settings screen and supporting a spoken language for recognition are different amounts of work, done by different people. An app’s interface text is translated by whoever builds the app, one language at a time. Speech recognition locales come from Apple’s own Speech framework, already built and maintained across a wide language catalog — an app just asks for a given locale rather than building recognition for it from scratch. That is why it is completely ordinary for an app to transcribe more languages than it has translated its own buttons into.

What changing your phone’s system language actually does here

• It can change the app’s own interface, if the new language is one the app has been translated into.
• It does nothing to which language a recording gets transcribed into — that stays whatever the transcription setting was already set to.
• It does not retroactively affect transcripts you already have, since those were produced by whatever locale was selected at the time.

The practical result: someone can run an app entirely in French while transcribing an English conversation, or the other way around. Neither setting leaks into the other, and there is no dependency to break — they are just two independent pickers that happen to live in the same app.

What to check if a transcript comes back in the wrong language

Not the phone’s system language — that was never the setting doing the listening. Check the transcription language picker inside the app itself, and confirm it is set to the language actually spoken in that recording, not the language the app happens to be displayed in at the time. A recording spoken in Spanish still needs the transcription setting pointed at Spanish, regardless of what language the rest of the phone is running in.

How Voice Studio handles this

Voice Studio keeps the two settings genuinely separate. The app’s own interface is available in 19 languages and follows your iPhone’s system language when that language is one of the 19, falling back to a default otherwise — purely a display choice with no effect on recordings. Transcription is a distinct setting with its own list of 38 supported locales, picked independently of the interface language and independently of whatever the phone as a whole is set to. Getting a transcript in the right language is a matter of that one setting matching the language actually spoken, nothing else.

Common questions

If I change my iPhone’s system language, will Voice Studio start transcribing in that language?

No. The system language can change the app’s own interface, if that language is one of the 19 it is translated into, but transcription uses a separate setting with its own list of 38 locales that has to be chosen on its own.

Why is the app showing English even though my phone is set to a language it can transcribe?

The interface only ships in 19 languages, while transcription covers 38 locales — a language can be supported for transcription without the app’s own screens having been translated into it, and in that case the interface falls back to a default.

Do I need to match the app’s interface language to the language I am recording in?

No. The two are unrelated. You can run the interface in one language and transcribe a recording spoken in a completely different one, as long as the transcription setting is pointed at the language actually spoken.

My transcript came back in the wrong language — what should I check first?

The transcription language setting inside the app, not the phone’s system language. Confirm it matches the language actually spoken in that recording rather than whatever language the app happens to be displayed in.