Multilingual Data Annotation Services

Your AI model is only as good as the language data behind it. Tomedes provides native-speaker recording, transcription, and annotation, with a QA review at every stage.

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What does it mean to annotate a dataset ?

To annotate a dataset is to add labels a machine learning model can learn from: a transcript for a recording, a tag on a phrase, a note on a sound. Multilingual data annotation does this in many languages, using native speakers who catch the accents, dialects, and context that automated tools miss.

AWS groups data labeling into three types: computer vision, natural language processing, and audio processing. Tomedes works on the two language-led types, speech and text, in 270+ languages.

Which data annotation services does Tomedes provide?

Speech data collection

Native speakers record prompted utterances on your recording platform, in the sampling rates your model needs, such as 8, 16, and 48 kHz.

Recording QA

Reviewers check audio quality, completeness, locale, and natural delivery, then approve each recording or return it for re-recording.

Verbatim transcription and annotation

Linguists transcribe exactly what was said and apply your labels for hesitations, unintelligible speech, and non-speech sounds.

ITN annotation

Inverse text normalization (ITN) turns spoken numbers, dates, and abbreviations into their written form, following your guidelines.

Annotation QA

A second reviewer checks each completed task against your guidelines and returns failed items for correction.

Text annotation

Native speakers label intent, sentiment, and named entities for chatbot and large language model training data.

Guideline translation

Annotation guidelines and labeling keys are translated for each project language, so every team follows the same rules.
Translation services

How much do data annotation services cost?

Price depends on the language, the task type, and the audio minutes or items in each batch. Tomedes quotes recording, recording QA, transcription and annotation, and annotation QA as separate lines, so each stage has its own rate. Send a sample task and your guidelines for an estimate.

How does a multilingual annotation project work?

A typical speech project runs in five steps.
Step 1: Scope. Share the language, locale, task type, and guidelines. Tomedes confirms native-speaker availability before kickoff.

Step 2: Pilot. A small batch tests the guidelines and sets the quality bar.

Step 3: Produce. Native speakers record, transcribe, or label in your tool or in a Tomedes workflow.

Step 4: Review. A second reviewer checks every completed task, and failed items go back for correction.

Step 5: Deliver and repeat. Approved batches are delivered, and the same team continues on repeat batches.

How does Tomedes keep annotation quality consistent?

Inconsistent labels train inconsistent models. Tomedes matches each task to a native speaker of the exact locale, adds a second review stage, and measures both against your written guidelines.

Documentation matters too. Article 10 of the EU AI Act lists annotation and labelling among the data-preparation steps covered by data governance for high-risk AI systems, and Tomedes is ISO 17100:2015 and ISO 9001:2015 certified for its language services.

For audio work, PickWriters lists Tomedes 4th of 10 among the transcription services it reviewed, in a list updated January 13, 2026.

Which languages does Tomedes annotate?

Tomedes works in 270+ languages. More than half of its active linguists are native speakers of a language outside the ten most requested in Tomedes project history, which matters when a model needs Tagalog, Amharic, or Yoruba speakers, not only Spanish and French.

ALL LANGUAGES

Who uses multilingual data annotation ?

Teams that train or test language-driven AI, and agencies that need native speakers fast.

  • checkSpeech recognition and voice assistant teams
  • checkConversational AI and chatbot builders
  • checkLarge language model and machine translation teams
  • checkLanguage service providers that need extra native-speaker capacity
  • checkAccessibility and captioning platforms
  • checkResearch labs and universities

Why choose Tomedes for multilingual data annotation?

Native speakers of the exact locale

Each task goes to a native speaker of the locale required, not a near match.

Hard-to-find languages

Tomedes has worked in 270+ languages since 2007, including regional and indigenous languages.

One project manager

A dedicated project manager coordinates linguists, reviewers, and delivery, and reports progress batch by batch.

Guidelines in every language

Tomedes translates your annotation guidelines and examples, so each language team works from the same rules.

FAQs

Answers to common questions about multilingual data annotation.

What is the difference between data annotation and data labeling?

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What are the four types of annotations?

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What is an example of an annotation?

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What is audio data annotation?

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Can I annotate data and get paid?

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How is speech data annotation priced?

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Which languages and locales can Tomedes cover?

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Can Tomedes translate annotation guidelines?

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