WhatsApp Voice Note Transcription Accuracy
What affects transcription accuracy for WhatsApp voice notes and how to get the best results from AI speech recognition.
You send a 2-minute voice note explaining a decision. The AI transcribes it as gibberish. Now the entire recap is wrong because the most important part of the conversation was mangled.
Transcription accuracy matters. Here is what affects it and what you can expect.
How WhatsApp voice note transcription works
WhatsApp records voice notes in the Opus audio format (.opus files). When you export a chat with media, these .opus files are included in the .zip.
ThreadRecap's voice-to-text tool uses OpenAI's Whisper model to transcribe these files. Whisper is currently the most accurate general-purpose speech recognition system available.
What affects accuracy
Audio quality
WhatsApp compresses voice notes aggressively. The audio is functional but not studio quality. Whisper handles this well, but there are limits:
- Clear speech in a quiet room: 95%+ accuracy
- Normal background noise (cafe, street): 90-95% accuracy
- Heavy noise (construction, wind, crowd): 80-90% accuracy
- Multiple speakers talking over each other: Lower accuracy
Language
Whisper supports 50+ languages with varying accuracy. English, Spanish, Portuguese, French, German, and other major languages get the best results. Less common languages or heavy regional dialects may see lower accuracy.
Speaking style
- Clear, deliberate speech: Best results
- Fast, casual speech: Good results (Whisper handles natural speech well)
- Heavy slang or code-switching: May miss some terms