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Call Translation

Your voice, translated in real time on Teams, Zoom or Meet

Call Translation turns your speech into a translated voice that the other person hears during the call. It is speech to speech: nobody has to read captions. You speak your language and the other side hears you in theirs — any of the 99 supported languages.

Requires your own OpenAI key
This is the one Speakly feature that does not run on the local models or on other providers — it uses OpenAI's realtime translation model. Add your key in Settings → Transcription → OpenAI. You pay OpenAI directly, around $0.04 per minute.

What you need

  • An OpenAI API key configured in Speakly
  • A virtual audio device installed (BlackHole on macOS, VB-CABLE on Windows) — both free
  • Your calling app: Teams, Zoom, Meet or any other

Step 1: install the virtual audio device

The operating system has no way to hand one app's audio to another app as a microphone. The virtual device is that cable: Speakly speaks into it, and Teams listens to it as if it were an ordinary microphone. One-time setup, about five minutes.

macOS

With Homebrew, run the command below — or download the installer from existential.audio/blackhole. Either way macOS asks for your password, because it is installing an audio device. No restart needed, but quit and reopen Teams/Zoom afterwards so they pick up the new device.

brew install --cask blackhole-2ch

Windows

  1. Download VB-CABLE from vb-audio.com/Cable
  2. Right-click VBCABLE_Setup_x64.exe and choose Run as administrator
  3. Click Install Driver, then reboot
  4. It installs one pair of devices: "CABLE Input" (an output) and "CABLE Output" (an input)

Step 2: set up Speakly

  1. Open the Call Translation tab
  2. Leave "Your microphone" on your real mic (headset, AirPods) — that is what gets translated
  3. Set "Translated voice output" to the virtual device: "BlackHole 2ch" on macOS or "CABLE Input" on Windows
  4. Set "They hear" to the language the other person should hear
  5. Click "Start translating"

Step 3: set up Teams or Zoom

  1. Teams: … → Settings → Devices → Microphone. Zoom: Settings → Audio → Microphone
  2. Pick "BlackHole 2ch" (macOS) or "CABLE Output" (Windows) as the microphone
  3. Keep the Teams/Zoom speaker on your headphones so you still hear the other person
Want to hear the translation too?
On macOS, open Audio MIDI Setup, create a Multi-Output Device with both BlackHole 2ch and your headphones checked, and select that device as Speakly's output. On Windows, go to Sound → Recording → CABLE Output → Properties → Listen and enable "Listen to this device".

Translating what the other person says

Call Translation also works the other way round: you hear, in your own language, what the other person is saying. In this direction no virtual device is needed at all — Speakly captures the system audio directly.

  1. In the Call Translation tab, switch the input from "My voice" to "Their voice"
  2. Set "You hear" to your own language
  3. Keep the output on your headphones
  4. On macOS the first run asks for Screen Recording permission — that is how the system grants audio capture

What it costs

OpenAI bills this model per minute of session, not per word or per token: about $0.034 per minute for the translation and the voice (one model, they cannot be separated), plus about $0.003 per minute for transcribing what you say, which fills the text panel. In practice a 30-minute call costs around $1.11. Speakly shows a live estimate during the call, but your OpenAI invoice is the source of truth.

Common issues

  • "No virtual audio device found": the device is not installed, or Speakly was opened before installing it — quit and reopen the app. Use the "Setup guide" button on the screen for the walkthrough.
  • The other person hears nothing: check that the microphone selected in Teams/Zoom is the virtual device, not your real mic.
  • You hear the translation but the call does not: Speakly's output is on your headphones instead of the virtual device.
  • Echo or doubled voice: Speakly's output is pointing at a device that is also its input — never use the same virtual device as both microphone and output in Speakly.
  • Region error: if your OpenAI organization has EU or US data residency, check the region configured in preferences.
Call Translation — Speakly