Simultaneous interpreter: human, RSI platform, or AI — what your multilingual meeting needs (2026)

A "simultaneous interpreter" is a profession: a person rendering speech into another language while it is being spoken — no pauses, no relay. What most people searching the term actually need is the outcome, and in 2026 there are three very different ways to get it — the interpreter in a booth, the RSI platform with remote interpreters, and AI simultaneous translation — with three cost structures that have nothing in common.

This guide separates the three, then compares named tools on a verifiable basis: what each vendor's public documentation states, with the source and the date we checked. We build one of them (InterMIND) — we'll say where it fits and where it doesn't.

The three ways to get simultaneous interpretation

1. The interpreter in the booth

Two interpreters per language pair, a soundproof booth, receivers for the room. This is how institutions and large conferences do it. The quality comes from professionals who understand context, irony, and jargon — the cost comes from the same place: qualified humans, booked by the day, per language pair, plus equipment. The weekly working meeting is simply not what this model is designed for.

2. RSI: the human interpreter, remote

Remote-simultaneous-interpretation platforms (Interprefy, KUDO, Boostlingo) deliver human interpreters' audio — sometimes with an AI option alongside — to participants' phones or headsets, on site or in a video call. The format remains an event: one speaker, an audience, languages fixed in advance, interpreters booked.

3. AI simultaneous translation

No interpreter here: a speech-recognition → machine-translation → speech-synthesis cascade renders the speech in each listener's language within seconds, with nothing to book. Only this form has marginal costs that fit an ordinary meeting — the category's tipping point. The question shifts accordingly: what does the tool translate, beyond the voice?

The questions that actually separate tools

An honest comparison doesn't ask "is the translation good?" — every vendor says yes. It asks three things:

One speaker, or everyone at once? Event tools optimize one stage → one audience, often one-directional. A working meeting is N people speaking, typing, reading, and replying at once — each in their own language, both directions. A tool that serves conferences well can be unusable for a four-person standup.

After the audio: what else comes back in your language? A meeting isn't just speech: it's the chat, the shared notes, the document dropped mid-session, the record you keep. Most tools translate the spoken moment and stop there — the translation evaporates the instant the talking ends. Ask every candidate literally: after the audio, what comes back in my language?

Where does it run, and what gets stored? For anything regulated — legal, medical, HR, finance — this is not a footnote but a procurement gate: is the audio stored, and does meeting content leave your jurisdiction? Our own answer: the live session retains nothing, and nothing derived from a meeting touches a US-hosted model — documented in the GDPR audit and GDPR-compliant video conferencing.

The tools, on the record

Every claim below comes from the vendor's public documentation, checked August 2026 (links at the end). "Not stated" means we found no claim in the public docs — ask the vendor if the point matters to you.

For events with interpreters (RSI)

• Interprefy — its documentation states 190+ languages and 6,000+ combinations with human interpreters, and 80 languages for its AI translation (audio and captions). (InterMIND vs Interprefy, feature by feature.)
• KUDO — RSI platform with an AI option: the KUDO AI Speech Translator page states translated audio and captions in 60+ languages, alongside human-interpreter delivery.
• Boostlingo — interpreter network: its site states 10K qualified interpreters and 275+ languages on demand, plus AI captions.

For multilingual working meetings

• Wordly — AI-only translation for meetings and events: its documentation states 60+ languages and 3,000+ language pairs, with attendees choosing text, audio, or both; its FAQ states translated transcripts and session summaries. Chat, shared-notes, and document translation are not stated in its public documentation (checked August 2026). (InterMIND vs Wordly, feature by feature.)
• DeepL Voice — the product page states live captions in 40+ languages inside Microsoft Teams, Zoom, and Google Meet; voice-to-voice output is listed as "coming soon" (checked August 2026).
• InterMIND — what we build: the whole meeting comes back in each participant's language, both directions. Voice — 23 languages, rendered in the speaker's own voice, live (how the cascade works); chat and shared notes — translated live, per participant, in the same 23 languages; documents dropped in-meeting (PDF, DOCX, PPTX, XLSX) — returned in 30 languages, formatting intact (the honest per-surface count); the post-meeting summary — generated in your language, on EU-hosted models with zero retention of meeting data (the GDPR audit). Quality is published, not claimed: the production cascade is scored monthly against FLORES-200, full per-pair distribution, at /benchmark.

Inside the platforms you already use

• Zoom — translated captions in 36 languages (Business Plus/Enterprise or a paid add-on); a Voice translator that renders translated audio (AI Companion, US-cluster accounts, desktop app 7.0+); plus audio channels for up to 20 human interpreters you source yourself. (Full breakdown.)
• Microsoft Teams — translated captions in 31 languages (Teams Premium or Copilot); an Interpreter agent that translates speech into speech and can simulate the speaker's voice (Copilot license); channels for 16 language pairs of human interpreters. (Full breakdown.)
• Google Meet — translated captions (Workspace Business Standard and above) and Gemini speech translation "in a voice like yours" (qualifying plans). (Full breakdown.)

The table: how much of the meeting comes back in your language?

Every cell reflects what the vendor's own public documentation states, checked August 2026.

Two honest notes on our own row: the counts differ per surface (voice/chat/notes 23, documents 30, website 17 languages — the breakdown and why); and voice quality is something you check on /benchmark, not in this table.

The decision shortcut

• Conference with an audience + human interpreters required → Interprefy, KUDO, Boostlingo.
• Working meeting, several people, both directions, AI → Wordly, DeepL Voice, InterMIND — and here, test three things specifically: the rendered voice (generic or the speaker's own), coverage beyond the audio (chat, notes, documents, the record), and quality that is published rather than claimed.
• Captions are enough → your existing Zoom/Teams/Meet, with the license gates from the table.

FAQ

What is the best software for simultaneous interpretation in meetings? Depends on the format. Event with an audience and interpreters: Interprefy (80 AI languages, 190+ with interpreters), KUDO (60+), or Boostlingo. Working meeting where everyone speaks, types, and reads in their own language, both directions: Wordly states 60+ languages as audio and text; InterMIND translates voice (23 languages, in the speaker's own voice), chat and notes (23), and documents (30) per participant. Captions only: Zoom (36 languages), Teams (31), or Meet, depending on plan.

What is the difference between a simultaneous interpreter and simultaneous translation? "Simultaneous interpreting" is the professional term for real-time spoken rendering — a profession with booths, two-person teams, and standards. "Simultaneous translation" is the everyday term for the same outcome, whether a human or a machine delivers it. Strictly, translation concerns text and interpreting speech — we unpacked the distinction and the types of interpreting here.

Can Zoom, Teams, or Google Meet interpret simultaneously? Yes, with plan gates. Zoom: translated captions in 36 languages (Business Plus/Enterprise or add-on) and translated audio via the Voice translator (AI Companion, US cluster). Teams: captions in 31 languages (Premium/Copilot) and the speech-to-speech Interpreter agent (Copilot license). Meet: translated captions (Business Standard+) and Gemini speech translation on qualifying plans. Per-platform detail: Zoom, Teams, Meet.

Is there AI simultaneous translation that keeps the speaker's own voice? Most AI tools render every speaker as the same synthetic narrator. A few state output close to the original voice: Teams' Interpreter agent can "simulate" the speaker's voice, Google Meet states "a voice like yours," and InterMIND renders the translation in the speaker's own voice via zero-shot synthesis, in 23 languages — how that works.

Can AI simultaneous translation be GDPR-compliant? The question resolves into three things you can ask any vendor: Is the audio stored or used for training? Where do the models that process meeting content run? And what happens to the derived material — transcript, summary, record? Our own answers are public: the live session retains nothing, and meeting content touches only EU-hosted models with zero data retention — documented in the GDPR audit and GDPR-compliant video conferencing.

See it for yourself

For the multilingual working meeting, the fastest test — for any tool, ours included — is to put your own meeting through it: talk, then check whether the chat, the notes, and the document came back in your language too.

• Try the live demo — InterMIND's production voice cascade, on your own audio, in any of 23 languages.
• Read the benchmark — monthly FLORES-200 scores, full per-pair distribution, no cherry-picking.
• How to evaluate a real-time meeting translator — the vendor-neutral foundation behind this guide.

Sources: Interprefy — AI translation languages, Interprefy — platform, KUDO — AI Speech Translator, Boostlingo, Wordly — translator languages, Wordly — FAQ, DeepL — Voice, Zoom — viewing captions in another language, Zoom — Voice translator, Zoom — Language Interpretation, Microsoft — live captions in Teams meetings, Microsoft — Interpreter in Teams, Microsoft — language interpretation in Teams, Google Meet — translated captions, Google Meet — Speech Translation, checked August 2026. Vendors expand plans and language lists over time; check their pages for the current state. InterMIND facts: per-surface language breakdown, live benchmark.