Live transcription and translation

You can receive speech as JSON objects, in real time, using the Zoom live transcription and translation feature (LTT). This feature can also translate speech from one language in real time to text in another language. This can power use cases like auto closed captioning, sentiment analysis, and language translation for e-learning.

For example, one user can say "Hello world" in English, and the other users can receive this speech, as text, in the language of their choice, like Italian "Ciao mondo", Spanish "Hola Mundo", and French "Bonjour le monde".

Zoom recommends that you provide an in-product notice to your end-users when a participant enables live transcription.

View usage

To monitor transcription (caption) and translation activity for your Video SDK sessions, see Build Platform → View usage reports: Captions and translation for detailed usage data.

Initialize LTT

After joining a session, call zoom.liveTranscriptionHelper to get the live transcription and translation client.

ZoomVideoSdkLiveTranscriptionHelper liveTranscriptionHelper = zoom.liveTranscriptionHelper;

Start transcription and translation

To start live transcription and translation, call zoom.liveTranscriptionHelper.startLiveTranscription().

const result = await zoom.liveTranscriptionHelper.startLiveTranscription();

Set speaking language

To specify the language you are speaking in, call the liveTranscriptionHelper.setSpeakingLanguage() function.

await liveTranscriptionHelper.setSpeakingLanguage(1);

Set translation language

To set the language you want speech text translated to, call the liveTranscriptionHelper.setTranslationLanguage() function.

await liveTranscriptionHelper.setTranslationLanguage(2);

Receive translation

To receive translated speech text, add the following event listener.

final liveTranscriptionMsgInfoReceivedListener =
  eventListener.addListener(EventType.onLiveTranscriptionMsgInfoReceived, (data) async {
    data = data as Map;
    ZoomVideoSdkLiveTranscriptionMessageInfo? messageInfo =
    ZoomVideoSdkLiveTranscriptionMessageInfo.fromJson(jsonDecode(data['messageInfo']));
    debugPrint("onLiveTranscriptionMsgInfoReceived: content: ${messageInfo.messageContent}");
  });

LTT best practices

When implementing Live Transcription and Translation (LTT) for your integration, consider the following best practices:

• If the feature is enabled for the session, provide a button to allow people to start closed captioning and select the spoken and translated languages.
• Display only the supported languages you wish to offer, rather than presenting all available options for transcription and translation.
• If the session won't include LTT, programmatically disable when the host starts the session. When someone joins the session, check if the feature is enabled by the host. If not, inform users.
• Use an event listener to detect when the host has enabled captions. You can use this to notify people that the feature is active, programmatically render a button for starting transcription or translation, or both.
• Set enableReceiveSpokenLanguageContent() to false if you don't want to receive the spoken language data.
• Use an event listener to detect when the host disables captions. You can use this to notify people who have enabled the feature that it has been disabled.
• Offer closed captioning customization options, such as font sizes and colors, to differentiate between transcription and translation texts, to enhance readability and follow accessibility standards.
• Inform people of these best practices when speaking:
  • Minimize background noise, avoiding activities like shuffling papers, typing loudly, or engaging in side conversations.
  • Speak clearly into the microphone.
  • Position the microphone near active speakers.
  • Opt for an external microphone over a built-in one to improve sound quality.

More LTT features

You can also control user audio volume and mute local audio to further refine live transcription and translation use cases.

For the full set of live transcription and translation features, see the Video SDK reference.