Accuracy is the most important factor in a live transcription app. An app that gets words wrong — especially in fast conversation or with unfamiliar vocabulary — can create more confusion than it solves. Understanding what drives accuracy helps set realistic expectations and choose the right tool.
What drives transcription accuracy?
Modern live transcription apps use one of two approaches to convert speech to text: on-device processing or cloud-based speech recognition.
On-device processing runs entirely on the phone without needing a connection. It is faster in low-latency terms and works offline, but is generally less powerful than cloud alternatives.
Cloud-based processing sends audio to remote servers that use large language models to transcribe it. This tends to deliver higher accuracy across a wider range of accents, speaking speeds, and vocabulary — at the cost of requiring an internet connection.
The other factors that most affect accuracy are:
- Background noise levels
- Distance between microphone and speaker
- Clarity of speech and regional accent
- Internet connection quality (for cloud-based apps)
- Technical or specialised vocabulary
What "good accuracy" looks like in practice
No live transcription app achieves 100% accuracy in real-world use. A realistic expectation for clear speech in a reasonably quiet environment is 90–95% word accuracy. That means occasional errors — particularly with proper nouns, place names, or technical terms — but the overall meaning of the conversation remains followable.
In noisier settings, accuracy drops. But even partial captions — catching the key words and the gist of a sentence — can make a significant difference compared to not having them at all.
How to test accuracy before committing
The most reliable way to assess accuracy is to try an app in the specific situations where it will be used most. Benchmark scores measured in ideal studio conditions rarely reflect performance at a noisy family dinner or in a busy GP surgery waiting room.
Most captioning apps are free to download. Download two or three, run them in the same real-world situation, and compare results directly. The winner in your environment is the right app for you.
Beyond accuracy: what else matters
Accuracy alone does not make a transcription app useful. Speed of display, readability of text, and ease of starting a session all affect how helpful an app is in a real conversation. An app that is highly accurate but takes ten seconds and four taps to start is less practical than one that is slightly less accurate but ready in an instant.
For everyday use — especially for people with hearing loss — an app that combines strong accuracy with large readable text and a one-tap start is almost always the better choice than one that prioritises accuracy alone.