How human church interpretation works
Traditional simultaneous interpretation (SI) involves a trained bilingual interpreter listening to the speaker through headphones and delivering a translated version of the speech in near-real time into a microphone. Attendees hear the interpreter through earpieces or a dedicated audio channel. Professional SI requires:
- Trained, qualified interpreters in the relevant language pair
- Equipment: interpreter console, headsets, and either a booth or remote connection
- For long services, typically two interpreters per language (they rotate every 20-30 minutes)
- Preparation: interpreters ideally receive sermon notes, theological terms, and speaker background in advance
How AI church translation works
AI-powered tools like Voco use automatic speech recognition (ASR) to transcribe the spoken sermon in real time, then apply neural machine translation (NMT) to produce text in the target language. This translated text is displayed on attendees' phones via a QR code — no headsets, no booth, no interpreter on-site. AI translation works entirely in the cloud, typically with under 3 seconds of latency from speech to displayed text.
Accuracy: where humans win
For highly technical, deeply idiomatic, or theologically dense content — particularly in language pairs with limited AI training data — human interpreters produce higher accuracy. A trained interpreter catches nuance, tonal shifts, and cultural context that current AI models may miss. They also handle accented speakers, overlapping speech, and off-script moments better than AI systems.
Accuracy: where AI holds its own
For clear, structured sermon content in major world languages (Spanish, French, Portuguese, Mandarin, Korean, Arabic, and most European languages), modern AI translation achieves practical comprehension levels for a listening congregation. The gap between AI and human interpretation has narrowed significantly since 2022 with the introduction of large language model-enhanced translation. For most weekly church services, AI accuracy is sufficient for congregation members to follow and engage with the teaching.
Cost comparison
- Human interpreter (UK market): £200–£800 per service per language, depending on language pair and experience
- Human interpreter (US market): $250–$1,000 per service per language
- AI translation (Voco): from £8/week — covers all languages, unlimited services that week
- Hardware earpiece systems: £500–£5,000 upfront plus maintenance
Logistics: human interpretation challenges
Finding qualified church interpreters in specific language pairs is increasingly difficult. Somali, Farsi, Twi, and many other diaspora languages have very few available interpreters, and those who exist are often not trained for live simultaneous work. Remote interpretation (over Zoom or KUDO) reduces the logistical barrier but adds technical complexity and can introduce audio latency. For weekly recurring use, the sourcing, scheduling, and cost of human interpretation is prohibitive for most churches.
When to choose human interpretation
- One-off high-stakes events (conferences, ordinations, formal ceremonies) where accuracy is paramount
- Languages with limited AI support
- Services where spoken audio delivery matters — some attendees strongly prefer hearing the interpretation rather than reading it
- Settings where phone use in the service is discouraged
- Languages with no written form or very limited digital presence
When to choose AI translation
- Weekly recurring services — the cost difference is decisive
- Multiple languages needed simultaneously
- No interpreter available in your target language
- Quick setup — no advance sourcing, no contracts, no scheduling
- Visitors and first-time guests — no one has to wear a headset