What is speech translation?

In this article, you learn about the benefits and capabilities of translation with Azure Speech. The Speech service supports real-time, multi-language speech to speech and speech to text translation of audio streams.

By using the Speech SDK or Speech CLI, you can give your applications, tools, and devices access to source transcriptions and translation outputs for the provided audio. Interim transcription and translation results are returned as speech is detected, and the final results can be converted into synthesized speech.

For a list of languages supported for speech translation, see Language and voice support.

Tip

Go to the Speech Studio to quickly test and translate speech into other languages of your choice with low latency.

Core features

The core features of speech translation include:

Real-time speech translation (standard)

Speech translation uses one standard API for real-time translation with text output, audio output, or both.

Use the standard speech translation API when you want to send an input audio stream in a specified source language and return translated text, synthesized speech, or both in your specified target language.

Multiple target languages translation

In scenarios where you want output in multiple languages, the Speech service directly offers the ability for you to translate the input language into two target languages. This enables you to receive two outputs and share these translations to a wider audience in a single API call. If more output languages are required, you can create a multi-service resource or use separate translation services.

If you need translation into more than two target languages, you need to either Create an Azure AI services resource or utilize separate translation services for more languages beyond the second. If you choose to call the speech translation service with a multi-service resource, note that translation fees apply for each language beyond the second, based on the character count of the translation.

To calculate the applied translation fee, see Azure Translator pricing.

Multiple target languages translation pricing

It's important to note that the speech translation service operates in real-time, and the intermediate speech results are translated to generate intermediate translation results. Therefore, the actual translation amount is greater than the input audio's tokens. You're charged for the speech to text transcription and the text translation for each target language.

For example, let's say that you want text translations from a one-hour audio file to three target languages. If the initial speech to text transcription contains 10,000 characters, you might be charged $2.80.

Warning

The prices in this example are for illustrative purposes only. See the Azure Speech pricing and Translator pricing for the most up-to-date pricing information.

Get started

As your first step, try the speech translation quickstart. The speech translation service is available via the Speech SDK and the Speech CLI.

You find Speech SDK speech to text and translation samples on GitHub. These samples cover common scenarios, such as reading audio from a file or stream, continuous and single-shot recognition and translation, and working with custom models.

Next steps

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