Transcriber
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Soniox speech-to-text for Bolna AI voice agents

Soniox stt-rt-v5 transcribes callers for your Bolna voice agent with one multilingual model that auto-detects and code-switches, including Hinglish.

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Official Documentation
At a glance

How Soniox fits in the stack

Best for

Turning noisy phone audio into text the agent can reason over.

Use this layer when

Recognition accuracy, language coverage, and latency matter most.

Connects to

Telephony audio upstream and your LLM downstream.

Voice Stack

Speech-to-text is the listening layer

Speech-to-text is the listening layer

This provider converts raw audio into text in real time. It shapes how accurately the agent hears the caller and how natural the back-and-forth feels.

TelephonyPhone Network
→
STTListener
→
LLMReasoning
→
TTSVoice
→
ToolsActions

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What is Soniox used for in a Bolna voice agent?

Soniox is a real-time speech-to-text provider that transcribes your callers with a single multilingual model, stt-rt-v5, which switches languages mid-sentence over one streaming connection. Pick it when callers mix English with a regional language, such as Hinglish, and you don't want to fix a language per call.

How do I set up Soniox with Bolna?

  1. Open your agent at platform.bolna.ai and go to the Languages tab.
  2. Under Transcription, select Soniox v5 as the transcriber.
  3. Choose the multilingual option for callers who mix languages, or pick a single language such as Hindi.
  4. Add brand terms in Keywords and a description of the call in Context, up to about 10,000 characters.
  5. To use your own account, add your SONIOX key under Settings → Integrations at platform.bolna.ai/providers.

For language codes and biasing, see the Soniox setup guide in the Bolna docs.

Which Soniox models and languages does Bolna support?

ModelLanguages on BolnaFeatures
stt-rt-v5 (Soniox v5)Multilingual auto-detect, English (en), English India (en-IN), Hindi (hi), Bengali (bn), Tamil (ta), Telugu (te), Gujarati (gu), Kannada (kn), Malayalam (ml), Marathi (mr), Punjabi (pa)Code-switching, per-token language identification, semantic endpoint detection, keyword and context biasing, 8 kHz telephony and 16 kHz web calls

For Indian-language-only agents, the docs suggest comparing Soniox with Sarvam speech-to-text.

What can you build with Soniox and Bolna?

Hinglish sales and collections. Handle callers who mix English and Hindi on outbound calls without reconfiguring the transcriber per contact.

One agent for many languages. Serve callers across the supported languages from a single agent instead of a separate agent or IVR branch per language.

Faster turn-taking. Semantic endpoint detection spots when the caller has actually finished, so the agent replies sooner without cutting people off.

A single Soniox key for voice and transcription. Pair the transcriber with Soniox text-to-speech, since one SONIOX key serves both.

FAQ

Soniox on Bolna: frequently asked questions

Yes. Select the multilingual option and Soniox detects and code-switches between English and Hindi in one stream, without you setting a language up front.

Hindi, Bengali, Tamil, Telugu, Gujarati, Kannada, Malayalam, Marathi and Punjabi, plus English, English (India) and a multilingual auto-detect option.

Yes. Add your SONIOX key under Settings → Integrations, using the STT filter. The same key also works for Soniox text-to-speech.

Yes. stt-rt-v5 is on Bolna's preferred model list, so it is covered by the flat per-minute rate.

Related

Other providers in this layer

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AssemblyAI

AssemblyAI Universal-3.6 Pro transcribes callers for your Bolna voice agent in 32 languages, with code-switching and keyword plus context biasing.

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Azure Speech-to-Text

Azure Speech-to-Text transcribes callers in real time for a Bolna voice agent, with speaker diarization, language identification and phrase lists of up to 2,000 terms.

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Deepgram

Deepgram is Bolna's default English transcriber, turning caller speech into text with Nova-3, Nova-2 or Flux streaming models on live phone calls.

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Text-to-Speech

Text-to-speech turns your agent responses into spoken audio. Voice quality shapes how callers perceive your brand. Flat, robotic speech kills trust while natural, expressive voices build it. Bolna integrates with the fastest TTS providers so responses sound human and arrive without awkward pauses.

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Tools & Workflows

Tools let your voice agents take action during a call, not just talk. Book a calendar slot, look up an order through your own API, push a lead into your CRM, or trigger a multi-step automation in Zapier. These integrations turn voice agents from answering machines into workflow engines.

See where Soniox fits in your production workflow

Use the demo to walk through provider selection, stack tradeoffs, and the exact workflow you want Bolna to automate.

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