How to Build a Multilingual Voicebot for Your Business

A multilingual voicebot is an AI-powered phone agent capable of understanding, transcribing, and speaking back to callers in multiple languages. For businesses operating in linguistically diverse markets like India, a single-language phone system is no longer sufficient. Callers expect to converse in their native tongue, whether that is Hindi, Marathi, Tamil, Telugu, or Indian English.

Bolti, a voice AI platform for building conversational phone agents, simplifies this process. Instead of stitching together complex speech-to-text (STT) engines, large language models (LLMs), text-to-speech (TTS) systems, and telephony pipelines, you can deploy a production-ready multilingual voicebot in under 10 minutes. Bolti offers a free trial with 50 minutes of call time, with pay-as-you-go pricing starting at just ₹6/minute.

In this guide, we will cover how a multilingual voicebot works, how to configure one, and how to scale your voice operations globally in 2026.

Why does your business need a multilingual voicebot?

If your customer support, outbound sales, or lead-qualification teams only operate in one language, you are missing out on a massive segment of your target audience. In India alone, over 90% of new internet and smartphone users prefer consuming content and interacting in regional languages rather than English.

Implementing a multilingual voicebot helps you:

• Scale operations instantly: Handle thousands of concurrent inbound or outbound calls in regional languages without hiring multilingual call center agents.
• Improve customer satisfaction: Give your callers the comfort of speaking their preferred language, leading to better conversion rates and faster issue resolution.
• Reduce operational costs: Replace expensive manual calling setups with automated voice agents that cost only ₹6/minute.
• Maintain 24/7 availability: Answer support queries, schedule appointments, or collect feedback after-hours without missing a single lead.

Whether you are looking to deploy agents for customer support, automated collections, or lead qualification, supporting local languages is the key to driving real business outcomes.

How does Bolti handle multilingual speech-to-text?

At the core of any multilingual voicebot is its ability to accurately hear and transcribe what the caller is saying. Bolti handles this through its Speech configuration settings, which let you choose the optimal speech-to-text (STT) provider and model for your specific target audience.

Within the Bolti dashboard, you can control three primary speech settings:

1. STT Provider: The underlying transcription service (such as Deepgram, Cartesia, AssemblyAI, or Microsoft Azure).
2. STT Model: The specific model optimized for transcription (for example, Deepgram’s nova-3 or Cartesia's ink-whisper).
3. STT Language: The expected language code of the caller's audio.

Choosing the right STT configuration

Depending on your target demographic, you can choose the best STT combination using this simple decision tree:

• Single regional language (e.g., Hindi): Use the default Deepgram nova-3 model with the language code set to hi. Deepgram provides industry-leading latency and high accuracy for Indian accents. If you encounter highly specific regional dialects and need alternative transcription, Cartesia's ink-whisper is an excellent backup supporting over 90 languages.
• Indian English: Set the language code to en-IN. This ensures the STT engine is tuned for Indian English pronunciations and accents, reducing transcription errors significantly compared to standard US English models.
• Code-switching / Hinglish: If your callers are likely to mix languages mid-sentence (e.g., switching between Hindi and English), use Deepgram nova-3 with the multi setting. This multilingual mode auto-detects the spoken language on the fly.

Explore how different industries utilize these language configurations by visiting Bolti use cases.

Selecting the best LLM for multilingual conversations

Once the caller's speech is transcribed into text, your voicebot needs an LLM to process the input, formulate a response, and decide on any necessary tool integrations (like booking an appointment in your CRM).

For multilingual agents, the choice of LLM directly impacts both response quality and call latency. While standard models like GPT-4o work well, Bolti also integrates with dedicated high-performance inference providers like Baseten to offer open-source models optimized for speed and cost:

• DeepSeek-V3.1 (671B MoE): This is the default recommended model for production voicebots. It offers the best balance of reasoning quality, multilingual capabilities, and low latency.
• Qwen3-235B-A22B: An incredibly powerful open-weights model that excels at complex reasoning and deep multilingual tasks where output quality is the highest priority.
• Llama-4-Maverick-17B: Best for scenarios requiring the fastest possible Time-to-First-Token (TTFT) and a massive 1-million-token context window.

Because voice is highly unforgiving of silence, selecting a low-latency model ensures your agent maintains a natural conversational flow with sub-second turn-taking, even when translating and responding in regional languages.

How to set up your multilingual voicebot in 5 steps

Building a voicebot with Bolti does not require complex coding. You can configure and deploy an agent directly from the web dashboard:

1. Create your agent: Log in to the Bolti dashboard and create a new agent. Give it a clear persona (e.g., "Marathi-speaking support representative") and define its primary business goal.
2. Set the primary language: In the Basic tab, select your primary language (e.g., Hindi, Tamil, or Gujarati). Bolti will automatically configure your Speech and TTS settings to match.
3. Refine STT settings: Go to the Speech tab. If you expect a bilingual audience, ensure the STT language is set to multi or adjust the provider to Deepgram nova-3 for fast, accurate regional transcription.
4. Connect a phone number: Buy a phone number directly through Bolti, or bring your own SIP trunk (using providers like Twilio, Exotel, or Plivo).
5. Test and launch: Use the built-in preview tool to make a test call. Converse with your agent in your target language, verify its pronunciation and response speed, and publish it live.

For developer-focused teams, every action available in the dashboard can also be executed programmatically via Bolti's open REST API, allowing you to spin up, manage, and track voicebots dynamically from your own software.

Try Bolti for your multilingual voicebot

Providing support in only one language limits your business growth in multilingual markets. With Bolti, you can build, test, and deploy highly responsive voicebots that speak Hindi, Marathi, Tamil, Telugu, English, and over 80 other languages.

Get started today with our 50-minute free trial and experience sub-second latency, real-time interruption handling, and human-grade voice quality. If you want to review our transparent pay-as-you-go rates, visit the Bolti pricing page.

Frequently Asked Questions

What languages does Bolti support?

Bolti supports over 80 global languages, with first-class support for Indian regional languages including Hindi, Marathi, Tamil, Telugu, Gujarati, Bengali, and Indian English.

Can the voicebot handle callers switching between English and Hindi?

Yes. By using the Deepgram nova-3 model on Bolti's Speech tab and setting the language to 'multi', the voicebot can auto-detect and transcribe code-switched speech (like Hinglish) in real time.

How much does it cost to run a multilingual voicebot on Bolti?

Bolti offers a pay-as-you-go pricing model starting at ₹6/minute. There are no hidden setup fees, and you can sign up to get 50 free minutes to test your voicebot.

Can I use my existing telephony provider with Bolti?

Yes. Bolti is built with a 'bring your own carrier' (BYOC) model. You can connect your existing SIP trunk from providers like Twilio, Plivo, or Exotel, or purchase phone numbers directly from the Bolti dashboard.