Verified answer
How many full-audio languages are listed on Steam?
Quick answer
Steam currently marks eight languages for full audio: English, French, Italian, German, Spanish from Spain, Japanese, Brazilian Portuguese, and Simplified Chinese.
What this means
All fifteen listed languages support interface and subtitles, but seven of them do not currently carry the full-audio checkmark. Console language packages can still vary by region.
Official source
Steam — official language matrix
Continue with the relevant guide
Open the related Control Resonant guide for the current topic summary, connected systems, and any later verified changes.
This answer is reviewed against pre-release official information. It states unknown boundaries explicitly and will be revised when Remedy or a first-party store publishes a newer fact.