Captio AI
🦻 Accessibility + 💻 Productivity App

Swahili live captions and productivity tool for phone & video calls

For deaf and hard of hearing people.

Download for free

Download on theApp Store
Captio AI app showing live captions

Download for free

Download on theApp Store
Use Cases

Every situation covered

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

👨‍👩‍👧Calls with family and friends

A WhatsApp call home to a relative in Mombasa or a catch-up with family in Nairobi. Fast casual Swahili, family shorthand, and prenasalized consonants that blur over a phone line. Captio AI captions everything said.

💼Work calls and conference calls

A team meeting run in Swahili from a Nairobi office or an online call with Tanzanian colleagues. Business Swahili mixes formal vocabulary with English terms. Captio AI keeps pace with both.

🏥Medical and healthcare calls

A callback from Kenyatta National Hospital in Nairobi or a NHIF query in Swahili. Medical calls use formal Swahili at speed. Captio AI shows the full message in text as it's spoken.

🏦Banks, utilities, and customer service

An M-Pesa customer service line, an Equity Bank IVR menu, or a Safaricom automated prompt in Swahili. Automated menus give you one chance. Captio AI shows each option before the timeout.

🌍International calls

A call from the Swahili-speaking diaspora in Germany, the UK, or the Gulf. Diaspora Swahili carries foreign-language influence on rhythm and vocabulary. Captio AI handles it.

📹Video calls — FaceTime, WhatsApp, Zoom

A WhatsApp video call with relatives in Zanzibar or a Google Meet with a Tanzanian team. All video call apps work the same way — put the call on speaker, open Captio AI, read the captions.

Performance

Most accurate and fastest models

Swahili
90.7%

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 calls you have been avoiding

Captions as they speak

Words appear on screen word by word while the other person is still talking. You read what they say at the same pace everyone else hears it — no delay, no reconstruction.

Works on any call app

Captio AI does not need to integrate with any platform. Put the call on speaker, point the microphone toward the audio, and read the captions. It works the same way for any app on any device.

No more asking for repeats

Every word is on screen as it is said. If you missed something, glance at the caption rather than interrupting the call — the full sentence is there.

Handles call audio accurately

Compressed phone audio is less clean than in-person speech. Captio AI is built for real-world audio conditions, including the reduced quality of standard phone and VoIP calls.

Any language

For calls with family abroad, international colleagues, or foreign-language customer service. Live Translator captions and translates in real time with no manual setup.

Record and review after

Record any call and upload it to Audio Transcription. Get a full written record of everything said — useful for medical instructions, work decisions, and anything worth having in writing.

Swahili

Why Swahili is hard to understand

Prenasalized consonants

  • Swahili's most common consonants start with a hidden nasal
  • Swahili prenasalized stops (mb-, nd-, nj-, ng'-) begin with a nasal closure before releasing. On a phone call, this initial nasal component is inaudible and the lip closure looks identical to /b/, /d/, /j/ — creating ambiguity across core vocabulary: mbwa (dog), ndio (yes), njia (path). These are not rare sounds — they appear in the most common Swahili words.

Coastal speech speed

  • Mombasa and Zanzibar Swahili is spoken significantly faster
  • Coastal Swahili — spoken in Mombasa, Zanzibar, and Lamu — is spoken at a much faster pace than the standard Swahili heard in broadcasting, with vowel elision between words. A deaf caller used to measured standard Swahili will struggle to follow a fast coastal market call or a WhatsApp voice note from a Mombasa relative.

Sheng code-switching

  • Nairobi Sheng rewrites words mid-call
  • Sheng — the urban argot of Nairobi that blends Swahili, English, Kikuyu, and other languages — is widely used by younger Kenyan speakers on phone calls. Words shift meaning and phonological shape rapidly, and Sheng vocabulary does not map to any single phonological system. A deaf caller tracking Swahili word shapes faces a continuously moving target.

Final vowel uniformity

  • Word boundaries blur into a stream of vowels
  • Swahili words nearly universally end in a vowel, removing the consonant variation that helps lip readers identify word boundaries in other languages. In connected speech, utterances can flow as a single unbroken vowel stream, and without the pitch and stress cues that hearing listeners use for segmentation, boundary identification becomes very difficult.

Swahili-English register shift

  • Professional calls switch languages mid-sentence
  • Business and professional Swahili calls in Nairobi and Dar es Salaam switch between Swahili and English within single sentences, especially for technical, financial, or formal vocabulary. The phonological system shifts abruptly with each language switch, requiring the deaf caller to track two separate systems simultaneously.

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The Challenge

Over 150,000 deaf Kenyans, and a phone system built around hearing

Kenya's 2019 national census counted 153,381 deaf people aged five and above — the majority (129,518) living in rural areas where healthcare, interpreter access, and assistive technology are least available. WHO projections indicate the hearing loss burden across sub-Saharan Africa will rise to 54 million by 2030, among the fastest-growing rates globally, driven by insufficient newborn screening, noise exposure, and limited audiological care.

Kenya's 2010 Constitution formally recognised Kenyan Sign Language (KSL) as the country's third official language — a landmark policy step. Tanzania has taken similar steps for Tanzanian Sign Language in broadcast contexts. Despite these achievements, KSL interpreters remain concentrated in Nairobi, and there is no national relay telephone service available through Safaricom, Airtel, or VoIP platforms. A deaf person in Kisumu, Mtwapa, or Nakuru who receives a bank callback or hospital appointment call has no practical real-time access option on their mobile phone.

Captio AI is built for exactly those calls: the M-Pesa customer service menu, the hospital callback from Kenyatta, the WhatsApp family call from Zanzibar. Point the phone at the speaker, open Captio AI, and read every Swahili word — including prenasalized consonants and fast coastal speech — in real time.

Download for free

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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

"WhatsApp voice calls with my family in Nairobi always left me guessing. Fast Nairobi Swahili sounds different from Mombasa Swahili and I was missing half of it. With Captio AI I read every word. First call I didn't have to ask them to use text instead."

Amina H. 🇰🇪
amina.h***@gmail.com
Moderate hearing loss, Mombasa

"M-Pesa and Vodacom customer care are all in Swahili and I couldn't follow the menus by ear. Captio AI shows me each menu option as the recording plays. I handle all my own calls now without needing a relative to do it for me."

Juma O. 🇹🇿
juma.o***@gmail.com
Profound hearing loss since childhood, Dar es Salaam

"Sheng on calls from my younger cousins in Nairobi is basically a different language. Captio AI keeps up with the code-switching and I finally understand what they're saying. Even the prenasalized consonants come out right in the text."

Fatuma A. 🇰🇪
fatuma.a***@gmail.com
Hard of hearing, Nakuru

"Zanzibar Swahili is fast and coastal — very different from what you hear on radio. Captio AI reads the fast coastal speech accurately. I use it for calls with my children who moved to mainland Tanzania."

Said M. 🇹🇿
said.m***@gmail.com
Age-related hearing loss, Zanzibar

"WhatsApp voice calls with my family in Nairobi always left me guessing. Fast Nairobi Swahili sounds different from Mombasa Swahili and I was missing half of it. With Captio AI I read every word. First call I didn't have to ask them to use text instead."

Amina H. 🇰🇪
amina.h***@gmail.com
Moderate hearing loss, Mombasa

"M-Pesa and Vodacom customer care are all in Swahili and I couldn't follow the menus by ear. Captio AI shows me each menu option as the recording plays. I handle all my own calls now without needing a relative to do it for me."

Juma O. 🇹🇿
juma.o***@gmail.com
Profound hearing loss since childhood, Dar es Salaam

"Sheng on calls from my younger cousins in Nairobi is basically a different language. Captio AI keeps up with the code-switching and I finally understand what they're saying. Even the prenasalized consonants come out right in the text."

Fatuma A. 🇰🇪
fatuma.a***@gmail.com
Hard of hearing, Nakuru

"Zanzibar Swahili is fast and coastal — very different from what you hear on radio. Captio AI reads the fast coastal speech accurately. I use it for calls with my children who moved to mainland Tanzania."

Said M. 🇹🇿
said.m***@gmail.com
Age-related hearing loss, Zanzibar

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FAQ

Frequently asked questions

Follow every call in Swahili.

Captio AI is free to start

Download for free

Download on theApp Store