Call centre stack: hear, understand, answer

In telephony everything hinges on the fact that audio is not text. Until a call is transcribed no language model can work with it, and until the transcript says who is speaking you cannot assess an agent at all. So a working setup is built from parts: speech recognition, speaker separation, meaning extraction and a voice reply. Each part can then be swapped and measured on its own, and a failure in one place does not turn the whole thing into a black box.

Updated 22 Sep 2026Find a model in 4 questions

Step 1. Transcribe the call

Speech recognition turns a recording or a live stream into text. Everything downstream depends on this step: if the model garbles product names and surnames, the analysis is built on fiction. Pay attention to phone-grade audio, background noise and how the model handles your language mixed with Latin-script brand names. Without this part you are back to listening to a sample of calls by hand.

What does the work

Speech to textRUGGUF2022–2025

Whisper

OpenAI · USA

Speech recognition in 99 languages, including Russian. The de facto standard for transcribing calls and meetings. Hugging Face's faster Distil-Whisper is English only.

  • Transcription of calls and video meetings
  • Video subtitles
  • Voice messages to text
Sizes
39M – 1,5B
Hardware
from: Laptop
Commercial use allowedDetails
Speech to textRUGGUF2024–2026

GigaAM

Sber · Russia

Sber's models for Russian speech recognition, among the most accurate for Russian. Includes emotion recognition, v3 with punctuation, and a multilingual version (Russian, Kazakh, Kyrgyz, Uzbek).

  • Transcribing calls in Russian
  • Meeting minutes
  • Voice control of services
Sizes
220M – 600M
Hardware
from: Laptop
Commercial use allowedDetails
Speech to textRU2023–2026

NVIDIA Parakeet / Canary / Nemotron Speech

NVIDIA · USA

Fast NVIDIA speech recognition models, including streaming ones for real-time use. Parakeet TDT v3 and Nemotron 3.5 ASR understand Russian.

  • Transcribing calls and meetings
  • Video subtitles
  • Real-time voice input
Sizes
110M – 2.5B
Hardware
from: Laptop
Commercial use with conditionsDetails

Step 2. Work out who is speaking

Speaker separation labels which line belongs to the agent and which to the customer, and tells speech apart from pauses and noise. Without it a transcript is one undivided block: you cannot measure who talked more, or check whether the required script was read out. In a live conversation the same part decides when the person has finished and it is safe to reply.

What does the work

Voice: speakers and sound2022–2025

pyannote (диаризация)

pyannoteAI (Hervé Bredin) · France

The most widely used open tool for splitting a recording by speaker: who spoke and when. Usually paired with speech recognition. Weights are issued after a short form on HF.

  • Tagging calls: which part is the agent, which is the customer
  • Meeting minutes with speaker labels
  • Preparing recordings for transcription and analysis
Sizes
a few million parameters
Hardware
from: Laptop
Commercial use allowedDetails
Voice: speakers and sound2022–2025

NVIDIA Sortformer / TitaNet

NVIDIA · USA

NVIDIA models for "who is speaking": TitaNet recognizes a specific person's voice, Sortformer splits a recording into up to 4 speakers, including live during a call.

  • Real-time speaker tagging in conversations
  • Checking that the same person is calling (voiceprint)
  • Preparing meeting transcripts
Sizes
23M (TitaNet) – 117M (Sortformer)
Hardware
from: Laptop
Commercial use with conditionsDetails
Voice: speakers and soundRU2020–2025

Silero VAD

Silero · Russia

The most popular open speech detector: tells voice apart from silence and noise. Processes an audio chunk in under a millisecond on a single CPU core; trained on recordings in more than 6,000 languages.

  • Cutting calls and recordings before speech recognition
  • Detecting when the customer is speaking in a voice bot
  • Filtering out silence and noise to save on transcription
Sizes
about 2 MB
Hardware
from: Laptop
Commercial use allowedDetails

Step 3. Extract meaning and draft the answer

The language model works with text by now: it pulls out the reason for the call, the topic, what was agreed and the next step, and in a live scenario writes the reply itself. Script compliance checks and flagging difficult calls for a supervisor also sit here. Drop this part and you are left with transcripts nobody reads, because nobody has time for hundreds of pages a day.

What does the work

TextRUOllama2023–2026

Qwen

Alibaba · China

A family of language models with strong Russian language support, from small versions for a laptop to a flagship on par with commercial APIs.

  • Chatbot and knowledge-base assistant
  • Replies to emails and customer requests
  • Document parsing and classification
Sizes
0,6B – 2,4T-A95B
Hardware
from: Laptop
Commercial use with conditionsDetails
TextRUGGUF2023–2025

Saiga

Ilya Gusev (IlyaGusev) · Russia

The best-known Russian community fine-tune: open models (Llama, Mistral, Gemma, YandexGPT) trained to act as a Russian-speaking assistant. A convenient starting point for a Russian chatbot on your own server.

  • Russian-language chat assistant
  • Answers based on the company knowledge base
  • Drafts of emails, descriptions and posts in Russian
Sizes
7B – 70B
Hardware
from: Laptop
Commercial use with conditionsDetails
TextOllama2023–2025

Llama

Meta · USA

The models that started mass open source in AI. A huge ecosystem of fine-tuned versions and tools.

  • Assistant for employees
  • Summaries of meetings and documents
  • Base for industry-specific fine-tuning
Sizes
1B – 405B
Hardware
from: Laptop
Commercial use with conditionsDetails

Step 4. Speak the answer

Speech synthesis voices the finished text. What matters here is not only how clean the voice sounds but how fast it starts: on a phone line a pause longer than a couple of seconds reads as a dropped call. Decide separately on intonation and on whether you tell the caller they are talking to a machine. Without this part you are limited to chat and notifications.

What does the work

Text to speechRUNot maintained2023

Coqui XTTS

Coqui · Germany

A popular model for cloning a voice from a short sample in 17 languages, including Russian. Coqui has shut down and development has stopped.

  • Voice cloning from a sample
  • Multilingual voiceover
  • Research and prototypes
Sizes
about 470M
Hardware
from: Laptop
Non-commercial onlyDetails
Text to speechRUGGUF2023–2025

Piper

Rhasspy / Open Home Foundation · USA

Very fast speech synthesis that runs even on a Raspberry Pi. Ready-made voices in 35+ languages, including several Russian ones.

  • Voicing notifications and bot replies
  • Voice for offline devices
  • Voice menus
Sizes
about 5M – 30M
Hardware
from: Laptop
Commercial use with conditionsDetails
Text to speechRU2022–2025

Silero TTS

Silero · Russia

Lightweight Russian speech synthesis that runs on a regular CPU. Version v5 added CIS languages and languages of Russia's peoples: Tatar, Bashkir, Yakut, Kazakh and others.

  • Voicing voice bot replies
  • Reading texts in Russian
  • Voices in the languages of Russia's peoples
Sizes
tens of megabytes
Hardware
from: Laptop
Commercial use with conditionsDetails

What to check before you start

The main trap is expecting the models to read calls as well as an experienced human does. Start with analysing calls that already happened rather than answering customers live: a mistake in analytics is cheap, a mistake in conversation costs you the customer. Test the chain on your own phone lines, not on studio recordings. Call recording, notifying the other party and storing voice data are regulated; this is a general description only, a lawyer should review your case.

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