Call and voice data annotation for AI

We prepare calls, dialogues and voice recordings for AI training — transcription, speaker diarization, intents, sentiment, classification and dialogue annotation.

From a test sample to a dataset for speech analytics, voice assistants and contact centers.

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Call and voice data annotation for AI and speech analytics

Voice data quality defines speech AI quality

Problem

  • incorrect recognition of utterances;
  • mixing speech from different participants;
  • intent errors;
  • incorrect request classification;
  • sentiment analysis problems;
  • lower voice-assistant quality;
  • unstable behavior on noisy or difficult calls.

Solution

  • transcribe conversations;
  • separate speech by speaker;
  • annotate intents;
  • mark entities and key phrases;
  • classify calls;
  • annotate sentiment;
  • handle noise, overlap and hard cases;
  • run multi-step quality control.

What is call and voice data annotation?

Call and voice data annotation is the preparation of recordings, transcripts and dialogues for speech recognition, speech analytics, NLP and voice assistants.

Depending on the task, a recording can be transcribed, split by speaker, divided into utterances and enriched with intents, emotions, sentiment, entities and other labels.

These datasets are used for automatic call transcription, service-quality analysis, request classification, voice bots and speech analytics.

Conversational data is natural speech. Real calls include overlaps, pauses, background noise, filler words, incomplete phrases, emotional speech and simultaneous talk.

A quality dataset therefore needs shared rules for transcription, diarization and classification.

Annotation types for calls and voice data

Speech transcription

Turning a conversation recording into text.

  • verbatim speech;
  • normalized text;
  • pauses;
  • interjections;
  • overlaps;
  • individual acoustic events.

Speaker diarization

Splitting a conversation by participant: agent, customer, several speakers, voice bot. Each utterance or time segment gets the matching speaker.

Audio segmentation

Splitting a recording into:

  • utterances;
  • meaningful fragments;
  • speech and non-speech intervals;
  • individual conversation stages.

Intent annotation

The purpose of the customer's request. The intent structure is defined per project.

  • consultation;
  • order;
  • return;
  • complaint;
  • technical issue;
  • service change;
  • cancellation;
  • repeat request.

Entity annotation

In dialogues:

  • products;
  • services;
  • dates;
  • amounts;
  • addresses;
  • order numbers;
  • organization names;
  • other entities.

Sentiment and call classification

Emotional tone of utterances or of the whole call. Categories by topic, outcome, customer type, reason and conversation scenario.

Annotation examples

Different annotation types for computer vision tasks

ML Pipeline

Full data preparation cycle from raw data to model-ready output

1
Data
Collect and prepare source audio data.
Order data prep
2
Annotation
Annotation aligned with task requirements.
Order annotation
3
Quality Control
Multi-step consistency and QA checks.
Check quality
4
Dataset
Final dataset in required format.
Get dataset
5
Model Training
Ready for ML/AI production pipelines.

Quality control

How we keep call annotation consistent

Conversational speech contains many ambiguous cases: overlaps, pauses, noise, unclear fragments and incomplete sentences.

Before launch we fix rules for transcription, speaker separation, classification and disputed cases.

Annotation passes several review levels so the same situations are handled the same way across the dataset.

01
Transcript accuracy
We check that the text matches the original speech and that the transcript is complete.
02
Correct diarization
We check that utterances are assigned to the right participants.
03
Intent consistency
The same request types must be classified by the same rules.

Where call and voice annotation is used

Speech analyticsCall content, request topics and communication outcomes.
Call and contact centersAutomatic processing of large volumes of agent-customer conversations.
Voice assistantsData for understanding user requests and training dialogue models.
Voice botsModels that recognize speech, detect intent and choose the next dialogue step.
Service quality controlCalls checked for specified scenarios, violations or deviations.
Automatic speech recognitionDatasets for ASR models.
Request classificationAutomatic routing of conversations by topic and category.
Dialogue NLPEntities, intents and other structured information from conversations.

Call annotation for speech analytics

Speech analytics turns large volumes of unstructured speech into data.

These systems can be trained on:

This annotation is used for automatic call classification, request analytics and NLP model training.

Data for voice assistants and voice bots

A voice assistant needs more than a transcript to understand the user.

The phrase has to be linked to its meaning.

For example, “I want to cancel the order”, “can the delivery be cancelled?” and “I no longer need the order” can belong to one intent.

US-DATA can annotate user utterances by intent, entity and additional attributes.

This data trains NLU systems and dialogue AI models.

AI for call and contact centers

AI systems can automate thousands of calls and analyze what is hard to review manually.

Annotated data can train models for:

US-DATA prepares a training dataset for the customer's call structure and business process.

Difficult conversational speech

Real calls are rarely clean studio recordings.

The data may include:

Rules for these cases are fixed in the guidelines before the project scales.

That keeps the dataset consistent even on a large volume of calls.

US-DATA advantages

Audio and text

We can process the source recording and the transcript together.

NLP annotation

Beyond transcription we add intents, entities, categories and other semantic labels.

Flexible guidelines

We follow the customer's instructions or help formalize the rules.

Difficult speech

Overlaps, background noise and other ambiguous cases follow agreed rules.

Scaling

Start with a test sample and increase volume after quality is confirmed.

Multi-step QA

We review transcripts, speaker labels and semantic categories.

Result for your ML project

1

Accurate call transcripts

2

Correct speaker separation

3

Structured intents and entities

4

Data for speech analytics and voice assistants

5

A dataset ready for training and testing

Voice data security

Access control and confidentiality at every project stage
Security & Compliance

Call recordings can contain personal and commercial information. Only specialists on the specific project receive access to recordings and transcripts. If needed, the work can run in the customer's system.

NDA.
Access rights separation.
Restricted staff access to materials.
Secure file transfer.
Work in the agreed infrastructure.
De-identification by an agreed process.
Compliance with applicable law and the customer's internal policies.

Pricing

Expandable sections with indicative cost tables.

Calculate annotation cost

Choose parameters and get instant estimate

Transcription
Diarization
NLP labeling
Classification
1,000 images

Our offer

Price per 1,000 units$150
Number of images1,000
Number of classes1
ComplexityLow
Project cost$150*

* This estimate is not a public offer. Final cost is determined after technical analysis and data review.

News

Latest materials on data annotation and machine learning

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Need call or voice data annotation?

Share sample recordings and describe the task — we will estimate the volume, transcription and semantic-labeling requirements and suggest a working format.

Call and voice data annotation for AI

Calls, voice assistants and contact centers produce large volumes of unstructured speech. To train artificial intelligence systems, that speech has to become a structured and consistent dataset.

US-DATA annotates calls and voice data for speech recognition, speech analytics, NLP and voice assistants. Depending on the project we provide transcription, speaker diarization, audio segmentation, call classification, intents, entities and sentiment. The base service is described on the audio annotation page.

Call transcription turns a recording into text for ASR and NLP models. A separate page covers speech transcription in more detail. If needed, the conversation is also split by participant and each utterance is assigned a speaker.

Speech analytics often needs more than a transcript: topic, customer intent, outcome, key entities and other parameters. Entities use NER annotation, request categories use text classification, and emotional tone uses sentiment analysis.

Voice assistants and voice bots also need annotated dialogues. Different phrasings of one request are grouped into shared intents, and individual words and phrases are marked as entities. Semantic text preparation relies on text data annotation. This helps the AI system understand the request, not only recognize speech.

Real contact-center recordings are especially difficult: overlaps, background noise, incomplete sentences, poor connection quality and conversational speech. Before scaling, US-DATA fixes the rules for these cases and runs a test batch.

If your project needs call transcription, voice data annotation, speaker diarization, a speech-analytics dataset or voice-assistant training, US-DATA will organize the process and prepare data in the agreed format for ML and AI models.