Captio AI
🦻 Accessibility + 💻 Productivity App

Tamil live captions and productivity tool for lectures

For deaf and hard of hearing people.

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Captio AI app showing live captions

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Use Cases

Every situation covered

Designed for the real moments that matter — not just quiet controlled environments.

🏛️Large lecture halls

Anna University, University of Madras, Madurai Kamaraj University, and Bharathidasan University lecture halls. Tamil-medium lectures in formal academic Tamil at pace. Place the phone on the desk facing the speaker. Captio AI captions from any row.

🔬Seminars and tutorials

Tamil university seminars where students present and discuss in formal Tamil mixed with English. Captio AI captions whoever is speaking so you follow every argument without losing your place.

💻Online and recorded lectures

Recorded Tamil lectures on university portals, YouTube academic channels, or WhatsApp shared recordings. Put the recording on speaker and point Captio AI at the audio for accurate captions in real time.

📚Study groups

Study groups in Chennai, Coimbatore, or Madurai — fast colloquial Tamil mixed with English for technical topics. Captio AI follows whoever is speaking in either register.

🌍Foreign-language and international courses

Tamil students in English-medium programmes, or international students following Tamil-medium lectures at Tamil Nadu universities. Live Translator captions in real time so language is not the access barrier.

🎤Guest speakers and public talks

Visiting academics from Sri Lanka, Malaysia, Singapore, and across the Tamil diaspora. Captio AI handles Indian Tamil, Sri Lankan Jaffna Tamil, and Singapore Tamil — any speaker at any venue.

Performance

Most accurate and fastest models

Tamil
90.4%

word accuracy

independent benchmark, 2025

< 200ms
you speak
captions

real-time captions

first word appears as you speak

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Captio AI in everyday use
Why Captio AI

Built for the pace and pressure of a real lecture

Follow without splitting your attention

Lip-reading and note-taking at the same time is an impossible cognitive load. Captio AI handles the following so you can direct all your attention to understanding what is being said.

Captions while the lecturer is still speaking

Words appear on your screen as they are said — not after the sentence ends. You stay in sync with the lecture rather than always being a beat behind.

Works in any lecture setting

Lecture halls, seminar rooms, online classes, study groups. Place the phone on your desk, point it toward the audio source, and Captio AI handles the rest.

A full transcript to study from

Record the lecture and upload it to Audio Transcription after class. Get a complete written record you can search, annotate, and revise from — at your own pace.

60+ languages

For international students, students studying abroad, or courses taught in a second language. Captio AI captions or translates in real time with no manual setup.

No advance notice needed

Official university captioning requires booking in advance and is not available for every session. Captio AI works for any lecture, any time, with no prior arrangement.

Tamil

Why Tamil is hard to understand

Formal-colloquial diglossia

  • Tamil lectures use classical formal Tamil — a register so different from spoken Tamil that it functions like a separate language on the lips
  • Tamil has a centuries-old diglossia: formal written Tamil (சென்றோர் Tamil / Sen Tamil) and colloquial spoken Tamil are grammatically and lexically distinct. University lectures in Tamil are delivered in formal register — which has different verb forms, different pronouns, and different vocabulary from everyday speech. A deaf student who has practised lip-reading colloquial Tamil encounters a different phonological and lexical landscape throughout the entire lecture.

Three distinct rhotics

  • Tamil distinguishes three rhotic sounds — ர, ற, and ழ — all visually similar but phonologically distinct
  • Tamil is unusual in having three rhotic consonants: ர (/r/ trill or tap), ற (/ɾ/ alveolar flap or trill in certain positions), and the unique ழ (/ɻ/ retroflex approximant, the Tamil 'zha' sound). All three are produced with tongue movement that is minimally visible on the lips. In academic Tamil, these distinctions carry lexical meaning — and all three look nearly the same from a lip-reading perspective.

Retroflex laterals and nasals

  • Tamil's retroflex lateral /ɭ/ and retroflex nasal /ɳ/ distinguish words with no visible lip difference
  • Tamil distinguishes the retroflex lateral approximant ள (/ɭ/) from the dental lateral ல (/l/) — and the retroflex nasal ண (/ɳ/) from the dental nasal ந (/n/). These contrasts are produced by curling the tongue back — a gesture entirely inside the mouth. In a lecture, these distinctions appear throughout the text and are not recoverable from lip shape alone.

Sri Lankan vs Indian Tamil

  • Jaffna Tamil and Chennai Tamil have genuinely different phonological profiles — both appear in Tamil-medium universities
  • Sri Lankan Tamil (particularly Jaffna Tamil) retains more classical distinctions than Indian Tamil, including contrasts that have merged in southern Indian spoken Tamil. Sri Lankan Tamil also has contact features from Sinhala. A deaf student calibrated to Chennai Tamil encounters different lip profiles when the lecturer has Sri Lankan Tamil as their native variety — and vice versa. Both communities are present in Tamil-medium universities across Tamil Nadu.

No audible word boundaries

  • Tamil connected speech has no pauses between words — segmentation depends entirely on hearing the lexical pattern
  • Tamil is spoken as a continuous stream with no reliable word boundaries in natural speech. Combined with the diglossia (formal Tamil uses longer, compounded forms), a deaf student cannot identify where one word ends and the next begins from lip movement alone. In a lecture delivered in formal Tamil at academic pace, the visual stream is continuous and largely undifferentiated.

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The Challenge

Hearing impairment accounts for 19% of all disability in Tamil Nadu — yet university captioning infrastructure is absent

Tamil Nadu has the highest concentration of deaf schools in India, yet this provision does not extend to university education. The 2011 Census found that hearing disability accounts for 19% of all disabilities in Tamil Nadu — representing approximately 1.18 million people in the state alone. A study published in PMC (PMC10431638) documenting factors affecting education access for disabled children in Tamil Nadu found that even when children attend school, skill acquisition is hindered by inadequate teacher training, inaccessible facilities, and poor availability of specialist education resources. The gap between school-level provision and university-level accessibility is not addressed by any existing institutional framework.

India has approximately 63 million people with significant auditory loss nationally, according to estimates from the National Programme for Prevention and Control of Deafness. Of these, Tamil Nadu carries a disproportionate share — both in raw numbers and in the density of the deaf community relative to other states. Indian Sign Language (ISL) remains without official national recognition, meaning that sign language interpretation is not a mandated service in Tamil Nadu universities. Tamil Sign Language (TSL), used by many deaf Tamilians, is distinct from ISL and has even fewer institutional resources.

Research published in PMC (PMC12199054) on disability among school children across India found that hearing impairment affected approximately 9.9% of disabled school-age children nationally — a figure that implies a large cohort moving toward higher education age without any real-time captioning provision waiting for them. For deaf and hard of hearing students at Tamil-medium universities, the lecture hall is the most demanding access challenge: formal academic Tamil, delivered at pace, in a diglossic register that differs significantly from the colloquial Tamil they navigate everyday.

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Privacy

What you hear stays with you.

Gone the moment it ends

Captio AI processes your audio in real time and discards it immediately. Nothing is recorded. Nothing is kept.

Not a product

Your conversations are not something Captio AI sells, shares, or monetizes — to anyone, for any reason.

Not used to train anything

What you say in a doctor's appointment or a job interview never ends up in a training dataset. Not ours. Not anyone else's.

100% PRIVATE

Private by default

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Reviews

People love Captio AI

"Anna University lectures are in formal Tamil that sounds completely different from everyday speech. Captio AI captures the academic register. I follow lectures instead of guessing half the words."

Priya S. 🇮🇳
priya.s***@gmail.com
Hard of hearing, Chennai

"The three Tamil rhotic sounds are invisible on the lips. Captio AI distinguishes them acoustically. Madurai Kamaraj University lectures are fully accessible for the first time."

Karthik R. 🇮🇳
karthik.r***@gmail.com
Deaf student, Madurai

"My professor switches between formal Tamil and colloquial Tamil mid-lecture. Captio AI handles both registers. I stopped missing the explanations that come in the informal aside."

Meena V. 🇮🇳
meena.v***@gmail.com
Hard of hearing, Coimbatore

"Singapore Tamil mixes Tamil and English differently from Indian Tamil. Captio AI handles both. NUS Tamil-medium classes and Singapore everyday Tamil are both accessible to me now."

Arjun T. 🇸🇬
arjun.t***@gmail.com
Hard of hearing, Singapore

"Anna University lectures are in formal Tamil that sounds completely different from everyday speech. Captio AI captures the academic register. I follow lectures instead of guessing half the words."

Priya S. 🇮🇳
priya.s***@gmail.com
Hard of hearing, Chennai

"The three Tamil rhotic sounds are invisible on the lips. Captio AI distinguishes them acoustically. Madurai Kamaraj University lectures are fully accessible for the first time."

Karthik R. 🇮🇳
karthik.r***@gmail.com
Deaf student, Madurai

"My professor switches between formal Tamil and colloquial Tamil mid-lecture. Captio AI handles both registers. I stopped missing the explanations that come in the informal aside."

Meena V. 🇮🇳
meena.v***@gmail.com
Hard of hearing, Coimbatore

"Singapore Tamil mixes Tamil and English differently from Indian Tamil. Captio AI handles both. NUS Tamil-medium classes and Singapore everyday Tamil are both accessible to me now."

Arjun T. 🇸🇬
arjun.t***@gmail.com
Hard of hearing, Singapore

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FAQ

Frequently asked questions

Follow every lecture in Tamil.

Captio AI is free to start

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