Monday, September 29, 2025

A conversation with Prof Rajeev Sangal by Shivanand Kanavi on Mission Bhashini

 

Genesis of Bhashini: India’s First AI Mission

A conversation with Prof Rajeev Sangal by Shivanand Kanavi

Prof. Rajeev Sangal, a pioneering computer scientist and former Director of IIT (BHU) Varanasi and founder Director of IIIT Hyderabad offers a masterclass on AI and language technology. A distinguished alumnus of IIT Kanpur and the University of Pennsylvania, Prof. Sangal is a world-renowned expert in computational linguistics, best known for his groundbreaking work on the Computational Paninian Grammar framework for Indian languages.

He conceived the Mission Bhashini and continues to guide it, as the founding Chair of Executive Committee of the Mission. He provides a rare, behind-the-scenes look at the conception and execution of India’s ambitious Bhashini mission for speech-to-speech translation, detailing its visionary strategy, the ethical dilemmas of AI opacity, the future of capturing linguistic nuance, and a strategic roadmap for India to achieve global leadership in domain-specific AI applications, making it an essential read for anyone interested in technology, governance, and innovation.



Prof Rajeev Sangal, chief architect of Mission Bhashini 

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One of the dreams of founders of Artificial Intelligence who met in Dartmouth College, in New Hampshire USA in 1956 and produced a “Manifesto of AI” was speech to speech translation using computers. Are we close to achieving it today? Will Mission Bhashini be the answer?

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Shivanand Kanavi: Tell us how was Mission Bhashini conceived?

Rajeev Sangal: Mission Bhashini was thought of by the Prime Minister’s Science Technology and Innovation Advisory Council (PM-STIAC). I was approached by Prof K Vijayraghavan, then chairman of the council, in September 2018, asking me if language translation could be addressed by technology, and to draw up a plan for it, particularly for S&T content in English.

I was happy that language technology was coming at the forefront of national priorities. I had demonstrated the machine translation technology we had developed to our PM, in February 2016 at BHU, when I was the Director of IIT (BHU) Varanasi.

Shivanand Kanavi: How did you go about conceptualizing the Mission?

Rajeev Sangal: When I was thinking about the mission, I had to look at the current situation - the state of the technology, access to devices by people, and their needs that could be fulfilled.

By now, smart phones had come in the hands of a large population, they were wanting to access content in their own languages on the internet. At that time, the volume of Indian language content was in even smaller quantities than today.

Even today the total content in all the Indian languages put together is less than 0.1% of the content on the internet. Yes, less than 0.1%  !

So, providing English content translated in local languages to common man would become desirable if the technology could be made ready.

The prevailing mindset at the time of conception of Bhashini in 2018-19 was that India did not have a demonstrated working machine translation much less any speech to speech machine translation system, and many people thought that there is no way India can catch up with the MNC tech giants.

These sceptics did not realize that Indian academia had the technical know-how, of building prototype models. This was a result of research and development of the past 30 years with government funding. Now, it was a matter of rebuilding those systems using the latest tools and approaches, and engineering the models for large scale use.

India had also gained experience in building Aadhaar (2009) and UPI (2016). What is today known as Digital Public Infrastructure. With the above capability and experience, it is no wonder that the Bhashini Mission has delivered a working technology at large scale, which is as good as or better than the one with MNC tech giants.



Shivanand Kanavi: What were the key ideas in the conception of the Mission?

Rajeev Sangal: One had to work out the scope, tasks, and types of uses. I felt that we should take speech to speech machine translation (SSMT), and not limit ourselves to text to text machine translation (MT). This might look like a simple expansion of the scope, but researchers in MT and in speech processing are quite separate - they work separately, and were often located in two different departments. Would it be possible to make them work together, towards a single goal?

A workshop was organized with leading researchers from both the areas in January 2019 at IIIT Hyderabad, to discuss possible approaches to be taken in the Mission. Consulting colleagues from both the areas, I felt confident that there was a willingness to work together. I knew that already there was a high level capability in both the areas in India. It is a testimony to the strength of Indian academia and proper governmental funding in the past under Technology Development for Indian Langauges (TDIL) program of Meity (Ministry of Electronics & IT).

It is a testimony to the strength of Indian academia and proper governmental funding in the past, even though in the recent past, there was a lull in funding.

I decided to take the plunge for Speech to Speech technology !

Educational courses on NPTEL / Swayam, besides web-sites, were the prime targets identified to be used for training in Machine Learning. It would allow students across the country to access content in higher education in their own languages.

Moreover, translation of formal lectures would be easier than conversations, because conversations use very short or partial sentences, and are highly contextual.

Complex technologies like speech processing and text to text translation make errors. So the system was designed to take human inputs as well, including corrections. It would normally function as a human machine combination, although as its quality improves it could also be used in a fully automatic mode.

Finally, it was also decided that all 22 official Indian languages together with English would be covered. The SSMT capability would be developed to translate among all these languages. When technology development is left to the MNCs, they choose to develop technology only in those languages for which there is a market need. As a result, almost one third of the languages are left out completely. Here, we would cover all 22 official Indian languages.

Shivanand Kanavi : What kind of technology was decided to be developed?

Rajeev Sangal : It was decided to develop AI models for spoken language translation. This included developing automatic speech recognition (ASR or speech to text) models, text to text machine translation (MT), and text to speech (TTS) models. These technologies when put in a pipeline would give the SSMT system. The pipeline would also contain, as needed, ancillary models for disfluency (breaks in speech) correction, named entity recognition, lip synchronization, etc.

Parts of the pipeline would also be usable as a standalone MT system for text to text translation, or a transcription system for speech. Human intervention would also be possible at every stage.

Such intervention would be important for correcting errors in recordings, though not in online live use. This basic technology would also open up the market for tools and support applications of various kinds, such as summarization, LLMs (which have come later), sentiment analysis. It was also decided to build OCR technology for recognition of Indian language text from images.

The above SSMT pipeline would be built for all 22 official languages of India, and go even beyond these languages later. If the technology is developed within the country, one has full control over it and one can put it to myriads of uses.

Shivanand Kanavi : What were some of the strategic elements in the design of the Mission?

Rajeev Sangal : A question arose as to how the technology built indigenously (’Made in India’) can compete with those developed by MNC tech giants like Google, Microsoft and Meta. They have the Indian language data (hundred times more than what we possess), the compute resources, and have captured the market as well.

When AI systems are tested under standard artificial benchmarks, they perform very differently compared to use in real life situations. Each “real life area” is a niche area. The Mission should have a mechanism for supporting the niche areas. For each domain or application area, the Mission should be able to help enhance technology and nurture startups. The support would be provided through “Technology Acceleration Centres”. Startups in these areas can compete and win against MNC tech giants. These ideas were built into the Mission document.

On the question of building strong research teams, the idea of “consortium” of academic institutions was used to build critical mass of researchers in a project. Language technology area needs computer scientists, linguists, Sanskrit grammarians, and also language experts of the concerned languages, all working together. A single institution usually lacks the required expertise. The 13 approved consortia included 70+ research groups located in 30+ institutions covering 22 Indian languages.

It was possible to run such a large distributed Mission, only because of the consortia approach. Even though at times the accounting software in Meity and other ministries is making it very difficult for consortia projects to work. This method of work has been crucial for progress.

On the issue of data, it was clear that a large amount of money would have to be budgeted for the creation of data for all 22 official Indian languages. This would mean capturing spoken data and its transcription for all the languages, and parallel sentences in the original language and its translation. It was also felt that to make the data freely available to Indian researchers and Indian startups, the data would be made open and freely downloadable by anybody.

Ironically this openness in the project would mean that this high quality data would be available to MNC tech giants also, for free.

They have much larger amount of data but of poor quality, gleaned from their users or from the internet. Therefore, I had reservations on this count, but mechanisms to restrict distribution of data do not work; they end up denying it to Indian researchers and startups. Not only the data, the models were also made open source and freely downloadable by anyone.

The goal of Bhashini was not just to deliver a technology, but to build an eco-system for language technology, with all these elements.     

Shivanand Kanavi : What were the elements of the eco-system of language translation that were identified?

Rajeev Sangal : The eco-system that Bhashini seeks to develop consists of R&D groups, data creation and collection groups, technology acceleration centres, mechanisms for technology transfer, incubation of startups, participation by other companies, state governments, and the users including publishers, course-ware developers, government departments, end users, etc.

This eco-system would be nurtured by Meity using Bhashini funds.

One can think of them as being a part of three different cycles in society: (a) technology cycle, (b) market cycle, and (c) social cycle. Each of the cycles had to be made active, and moreover, these cycles have to be mutually reinforcing.

Shivanand Kanavi : What are these cycles ? Can you explain.

Rajeev Sangal : The first cycle is the technology cycle. It provides linkages between R&D and startups. R&D does research, finds new ways of doing things, builds lab prototypes to field prototypes - leading to new technology development and its demonstration.

Startups and existing companies take this technology, convert it into products, and service the customers.

However, for the technology to be transferred to companies, the technology has to be “engineered” for robustness, ruggededness, and adaptation to needs of real life customers. This task needs to be done by a separate entity, call it technology accceleration centres (TACs). They have to connect with startups and help them solve problems which come in the way of adaptation of “new” technologies. This is called a cycle because there is a two way flow between the two.

The second cycle is the market cycle. It involves, for example, the content providers such as publishers giving services to their customers or end users. However, they need modern translation tools as well as other AI tools, to make their tasks easier. This is where technology based startups come in, in making the content in multiple languages or provide new kinds of services, including voicebots. These help the providers in reaching their end users.

The third is the social cycle. The task here is to get a large number of people into creating Indian language digital content - both original and translated, proliferation of use of language tools, contributing to languages through teaching, contests, games, etc.

The principle actors here are schools, colleges, language departments and academies, culture departments, students, state governments, and general masses. This cycle yields love for culture and languages, encourages language aware and digitally trained manpower including e-translators, and of course, precious data. Linking with state governments is an important step in this cycle.

These cycles are driven by their inner dynamics. Technology cycle is driven by knowledge, market cycle by money, and the social cycle by service.

In the Mission, major progress has been made currently in the development of technology, and some progress with central government or its ministries as user. The market cycle and the social cycle need to be specially energized, as they are much delayed.

Shivanand Kanavi : What are the outcomes of the Bhashini Mission so far?

Rajeev Sangal : Mission Bhashini has led to the development of a range of technologies for SSMT (speech to speech machine translation) for Indian languages. These technologies have been made ready not just as a lab or field prototype, but engineered for large scale use. These are the result of R&D and good engineering. OCR technology is also under development.

The above technologies are available in 20+ Indian languages, with 350+ different AI models. Bhashini app has been available for free download for some time and provides basic services over mobile phone.

A large number of government ministries are using these technologies, provided as a free service by Meity. Many of these are as voicebots to assist the users in availing online services, including enquiries about government schemes, filling forms, etc.

Bhashini technology has been used in translating lectures and course material for higher education available on NPTEL and Swayam platforms. This has been accomplished by video to video translation of lectures from original English into some 8 Indian languages. More than two hundred courses have been translated. Subtitling facility has also been made available. More languages and courses are being covered as an ongoing activity.

Open sourcing of data and models, has allowed Indian language data to be used by a large number of individuals, institutions, and startups as free downloads.

What needs to be done now is to develop the market cycle by nurturing startups. They really need to provide services to their customers; governments or private. Various sectors are waiting to be exploited, such as health, agriculture, school education, etc.

Technology acceleration centres planned under the Mission can go a long way in energizing the startups in the eco-system.

R&D needs to continue the exploration of completely new ways of building technology which can handle prosody in speech processing, and discourse in machine translation.

Shivanand Kanavi: What is prosody in speech ?

Rajeev Sangal: Prosody in speech refers to the rhythm, stress, and intonation of spoken language, or the "music" of speech, and it conveys meaning and emotional nuance beyond individual words. It uses features like pitch, loudness, and duration to signal things such as a statement versus a question, the speaker's emotions, sarcasm, or emphasis on certain words.  

In future, these systems would utilize features from prosody such as tonal changes, pauses, emphasis, and sentiments in Indian languages. Similarly, MT would not be limited to sentence to sentence translation at a time but do paragraph to paragraph translation. Indian academia is well poised to do it.

Finally, the social cycle needs to be jump started. It would mean involving the common man in building content for their languages, become adapt in using translation tools under Bhashini, and finally become the creator of original content in Indian languages. State governments can play a major role in this. A revolution in Indian languages is waiting to be unleashed.

(to be continued)

Shivanand Kanavi, a frequent contributor to Rediff.com, is a theoretical physicist, business journalist and former VP at TCS.
He is the author of the award winning book Sand to Silicon: The Amazing Story Of Digital Technology  and edited Research by Design: Innovation and TCS.