Solving Regional Language Speech Recognition Accuracy in India for Phone Calls

Bolti, a voice AI platform for phone agents, helps businesses run automated phone interviews without losing qualified candidates to poor transcription. If you are hiring high-volume roles in India—such as delivery partners in Bengaluru, warehouse staff in Pune, or BPO agents in Noida—you know that standard voice bots fail when candidates speak with regional accents or mix Hindi and English. With Bolti's flat ₹7/min pay-as-you-go pricing and a 50-minute free trial, you can deploy conversational agents that accurately understand natural Indian speech on noisy telephony lines.\n\n## Why is regional language speech recognition accuracy in India difficult on phone calls?\n\nTelephony audio is highly compressed, and Indian candidates frequently switch between English, Hindi, and regional languages in a single sentence. This combination of low-bandwidth 8kHz audio and localized accents causes standard global speech-to-text (STT) engines to misinterpret responses, leading to high drop-out rates during automated screening processes.\n\nWhen hiring at scale in India, recruiters face three distinct technical hurdles on the phone:\n\n* Telephony Compression: Mobile networks compress audio down to 8kHz. This removes high-frequency sounds, making it hard to distinguish similar-sounding words, especially when candidates are speaking on the move or in noisy environments.\n* Code-Switching (Hinglish/Tanglish): Candidates rarely speak textbook English or pure Hindi. They naturally blend languages, saying things like "Mera experience two years ka hai" or "I am looking for a change, sir." Standard STT models trained on single-language datasets fail to parse these transitions.\n* Phonetic Variations: A candidate from Kolkata, Chennai, or Ludhiana will pronounce English vowels and consonants differently. Standard models trained on US or UK accents fail to map these variations accurately, resulting in incorrect transcriptions and failed screening filters.\n\n## How Bolti handles diverse Indian accents and mixed languages\n\nBolti resolves this by letting you choose and configure localized speech-to-text (STT) engines optimized for Indian phonetics. Instead of forcing you to use a single rigid model, Bolti's modular architecture lets you select specialized providers like Fennec or Deepgram Nova-3 to match your candidates' regional backgrounds.\n\nTo handle real-world Indian phone calls, Bolti uses a real-time stack tuned specifically for telephony:\n\n* Sub-Second Latency: Turn-taking happens in under a second. The system does not make the candidate wait in awkward silence while processing their accent, keeping the conversation natural and engaging.\n* Telephony-Grade Noise Cancellation: Background noise from traffic, fans, or crowded rooms is filtered out before the audio reaches the transcription engine, ensuring clean audio input.\n* Interruption Handling: If a candidate starts speaking while the agent is talking, the agent stops immediately to listen, mimicking a natural human conversation.\n\n### Example of Hinglish transcript handling\n\nHere is how a typical candidate response is processed by Bolti's default configuration:\n\n* Candidate audio: "Sir, main currently Bengaluru mein delivery job kar raha hoon, but abhi change chahiye."\n* Standard STT transcription: "Sir, my currently Bangalore main delivery job car high home, but abhi change." (Failed match)\n* Bolti (Deepgram Nova-3 Multi): "Sir, main currently Bengaluru mein delivery job kar raha hoon, but abhi change chahiye." (Perfect transcription, passed to the LLM for accurate screening evaluation)\n\n## Step-by-step: Configuring your voice agent for Indian candidates\n\nSetting up an accurate agent takes under ten minutes in the Bolti dashboard. You simply choose your STT provider, set the correct region-specific language code, and write a system prompt that explicitly allows conversational, bilingual responses.\n\nFollow these steps to build an agent optimized for Indian candidates:\n\n1. Select your STT Provider: Go to your agent's Speech tab. Choose Deepgram or Fennec based on your primary language requirements. Deepgram is the default and is highly recommended for general use.\n2. Set the STT Language Code: If candidates speak Indian English, set the language code to en-IN. If they speak a mix of languages, select multi (supported by Deepgram Nova-3) to auto-detect and transcribe code-switching in real time.\n3. Write a Bilingual Prompt: In the LLM tab, instruct the model to accept and respond in the candidate's preferred style. For example: "You are screening candidates for a delivery role. Accept responses in English, Hindi, or Hinglish. Keep your replies simple and conversational."\n4. Connect Your Telephony: Bring your own SIP trunk from Exotel, Plivo, or Twilio, or use a Bolti-provided number to start making and receiving calls.\n\n## Comparing STT providers for Indian voice agents\n\nChoosing the right speech-to-text provider is critical for maintaining high regional language speech recognition accuracy in India. Bolti supports multiple top-tier STT providers so you can match the right engine to your audience.\n\nHere is how the main options compare for Indian phone calls:\n\n* Deepgram (Nova-3): This is Bolti's default model. It provides excellent latency and robust support for Indian English (en-IN) and Hindi (hi). The multi setting is highly effective at transcribing rapid Hinglish code-switching.\n* Fennec (Fennec-ASR): Optimized specifically for Indian regional languages. Choose Fennec if your candidates are speaking primarily in Hindi, Tamil, Telugu, Kannada, or Marathi. It outperforms global models on highly localized accents.\n* Azure Speech: An enterprise-grade provider with broad language coverage. Azure is ideal for teams with strict compliance requirements or those needing niche regional dialects.\n\n## Set up your first HR-screening agent on Bolti\n\nDeploying high-accuracy multilingual phone agents for your hiring pipeline takes only a few minutes. With Bolti's flat ₹7/min pay-as-you-go model and 50 free minutes of call time, you can test how our platform handles real-world accents without any upfront commitment. Start your free trial today to build an agent that understands your candidates, or contact our enterprise team for custom deployments and on-premises requirements.

Frequently Asked Questions

Does Bolti support regional Indian languages like Tamil, Telugu, and Marathi?

Yes. Bolti supports Hindi, Marathi, Tamil, Telugu, Bengali, Gujarati, English, and over 80 global languages. You can select specialized STT providers like Fennec or Deepgram Nova-3 to handle regional phonetics.

Can Bolti's voice agents understand Hinglish?

Yes. By using Deepgram Nova-3 with the language code set to 'multi', Bolti can auto-detect and transcribe mixed languages like Hinglish, ensuring candidates are not penalized for code-switching.

How does Bolti handle background noise on mobile phone calls?

Bolti features telephony-grade noise cancellation and real-time audio processing to filter out street noise, traffic, and background chatter before the audio is transcribed by the STT engine.

Can I use my existing Indian telephony providers with Bolti?

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