Hindi Speech To Text API: High-Accuracy Voice AI for Indian Calls

Bolti, a voice AI platform for building production-ready conversational phone agents, provides a high-accuracy Hindi speech to text API built specifically for real-time phone conversations. Whether your customers speak pure Hindi, mix it with English (Hinglish), or speak with regional accents, our platform processes voice inputs with sub-second latency to make automated phone calls feel completely natural. You can start building today with a free trial that includes 50 minutes of call time.

Traditional speech-to-text (STT) engines are trained on clean, studio-recorded audio. When applied to real-world phone calls in India—where background traffic noise, cellular network drops, and mixed-language speech are the norm—standard models fail. Bolti solves this by integrating telephony-grade noise cancellation and specialized multilingual models designed for the unique flow of Indian voice interactions.

What is a Hindi speech to text API for voice calls?

A Hindi speech to text API for voice calls is a technology that converts spoken Hindi audio from a phone connection into structured text in real time. Unlike static transcription services used for pre-recorded files, a real-time conversational voice API must transcribe speech instantly so an AI agent can understand the caller and respond without awkward pauses.

On the Bolti platform, this transcription happens as part of a continuous loop:

1. Real-time Audio Streaming: The caller's voice is streamed directly from your SIP trunk (like Twilio, Plivo, or Exotel) into Bolti's audio processing pipeline.
2. Noise Filtering & Transcription: Telephony-grade noise cancellation strips out honking, wind, and market noise before the Hindi speech-to-text engine transcribes the audio.
3. LLM Processing: The transcribed Hindi text is immediately sent to a Large Language Model (LLM) to determine the next action or response.
4. Text-to-Speech (TTS): The system generates natural, human-like Hindi audio to speak back to the caller, completing the turn in under a second.

Why standard transcription APIs fail on Indian phone calls

If you have ever tried using standard global cloud transcription services for Indian customer support or outbound sales, you have likely run into these three major roadblocks:

• The Hinglish Mix: Indian callers rarely speak textbook Hindi. They constantly blend Hindi and English words (e.g., "Mera order status check karo" or "Address change karna hai"). Standard APIs treat this as an error or try to force-translate the words, which ruins the context.
• Telephony Noise: People call while walking on busy roads, riding metro trains, or standing in crowded markets. Without dedicated noise cancellation, background noise is transcribed as gibberish, confusing the AI agent.
• High Latency: In a live conversation, a delay of even two seconds feels like an eternity. Standard APIs designed for post-call transcription cannot stream audio and return text fast enough to maintain a natural conversation flow.

Bolti's architecture is optimized specifically to handle these challenges, ensuring that your automated agents can handle complex customer queries without missing a beat. You can explore how companies deploy these agents across various industries on our Bolti use cases page.

Key features of Bolti's Hindi voice processing

Bolti is built from the ground up for production-grade telephony. When you build a voice agent using our platform, you gain access to a suite of features designed for enterprise-grade performance:

• Sub-Second Latency: Our optimized audio pipeline minimizes the time between when a caller stops speaking and when the agent responds, keeping turn-taking natural and fluid.
• Real Interruption Handling: If a customer interrupts the AI agent mid-sentence, Bolti instantly stops the agent's playback and starts listening to the new input—just like a human would.
• Bring Your Own Carrier (BYOC): You can connect your existing Indian SIP trunks (such as Exotel, Tata, or Airtel) directly to Bolti, or use our pre-configured phone numbers.
• Enterprise-Grade Security: We protect sensitive customer data with robust security measures. All transcripts are workspace-scoped, and we offer PII redaction at runtime to ensure compliance with DPDP and GDPR guidelines.

How to trigger external APIs using Hindi voice commands

Transcribing Hindi is only the first step. To make your voice agent truly useful, it needs to take actions based on what the caller says. Bolti achieves this through Workspace HTTP Tools, which allow your voice agent to interact directly with your backend systems.

For example, if a customer says, "Mera booking cancel kar do" (Cancel my booking), the flow works like this:

Caller: "Mera booking cancel kar do" 
   │
   ▼ [Hindi STT] -> "Mera booking cancel kar do"
   │
   ▼ [LLM] -> "I should call cancel_booking with booking_id=9876"
   │
   ▼ [Bolti Tool Execution] -> Sends an HTTP POST to your API (e.g., https://api.yourcompany.com/bookings/cancel)
   │
   ▼ [Your API Response] -> { "status": "cancelled", "refund_initiated": true }
   │
   ▼ [LLM] -> "Aapki booking cancel ho gayi hai aur refund initiate kar diya gaya hai."
   │
   ▼ [Hindi TTS] -> Natural spoken audio played back to the caller.

You can configure these tools once in the Bolti dashboard and assign them to any agent in your workspace. This makes it easy to connect your voice agents to CRM databases, payment gateways, and booking systems.

Transparent and affordable pricing for Indian businesses

Many voice AI platforms hide their pricing behind complex sales cycles or charge expensive platform fees. Bolti keeps it simple with a transparent, pay-as-you-go model:

• Flat Rate: Only ₹6 per minute for complete voice calls (including speech-to-text, LLM processing, and text-to-speech).
• No Hidden Fees: No setup fees, monthly minimums, or platform lock-ins.
• Free Trial: Every new account gets 50 free minutes to build, test, and deploy their first voice agent.

To see how our rates compare to traditional call centers or other automated systems, visit our detailed Bolti pricing page.

Set up your first Hindi voice agent

Creating a high-performance Hindi voice agent takes less than 10 minutes on the Bolti platform. You do not need a background in machine learning or speech science to get started—our intuitive dashboard and open APIs let you configure prompts, select voices, and connect tools with ease.

Sign up for a free account today to get your 50 free minutes of call time and start building. Create your free Bolti account and experience high-accuracy Hindi speech-to-text in real time.

Frequently Asked Questions

Does Bolti's Hindi speech to text API support Hinglish?

Yes. Bolti is designed to understand natural Indian speech patterns, which frequently mix Hindi and English (Hinglish). The model accurately transcribes mixed-language sentences without losing context.

What is the pricing for using the Hindi voice API?

Bolti charges a flat, pay-as-you-go rate of ₹6 per minute. This includes speech-to-text, LLM processing, and text-to-speech. There are no monthly platform fees, and new accounts get 50 free minutes.

Can I connect my own Indian phone numbers or SIP trunks?

Yes. Bolti supports Bring Your Own Carrier (BYOC). You can easily connect your existing Indian SIP trunks from providers like Exotel, Plivo, Twilio, or local telecom operators directly to your Bolti workspace.

How does the platform handle loud background noise?

Bolti uses telephony-grade noise cancellation built specifically to filter out environmental sounds like traffic, wind, and ambient chatter before the audio is processed by the Hindi speech-to-text engine.