Smart Voice Calculator

Smart Voice Calculator – an experimentation gone right!

  • Experimental API

These last couple of weeks, I have been working on an experimental api. Speech recognition, has and always will be a wonder for me. Being able to command and get something done. What more could someone who loves automation want?


Being not very good at maths at school, I wanted to understand how calculators work. I can tell you it’s not as easy as I would have initially thought. I first tried the classic add, subtract, multiply and divide two numbers. That was quite easy.

The real challenge is allowing infinite numbers and operations in succession. How would you deal with that? Well, it took me some time to realise that I needed to have to replicate the exact functionning of an actual calculator.  Of course, I wouldn’t use logic gates but I was very keen to emulate the phenomena.

Once that was done. I was ready to embark in the wonderful world of zeroes and ones.

Speech Recognition Coming in!

That was the cool part. The fun lies in speaking and getting hits based on what was said or how misinterpreted I was.

Trying to change my accent worked really well. The extension has not been tested  extensively on other hardware though.

Basically, did most of the tests on my gaming headset (Kingston HyperX Cloud). It has a very high quality microphone and of course clarity of voice helps.

Smart Voice Calculator

Smart Voice Calculator

Once everything started to work as expected, I still had another goal in mind.  Make the app give a voice feedback. Make Smart Voice Calculator not only understand, but also respond.

Speech Synthesis

Had to learn to use another api to make the app speak back to me. The documentation had been lacking but I wouldn’t complain.  I experimented as much as I could with different voices, alternating calls till it worked!

User Interface

The UI has been the key word in this project. It has been reworked multiple times. My goal was to give the user the most pleasant experience! I really hope you enjoy this little app 🙂



– Evaluates numbers and operations in any order.

– Voice feedback for results

– Calculates confidence level based on your voice.

– Temporary results shows what is happening behind the scenes.(optional)

– Approximates results (optional)

How does it work?

Smart Voice Calculator extension

  1. You’ll have to download the chrome extension on the website.
  2. Click on the extension icon and the app will load.
  3. It awaits voice command right after clicking on the calculator.
  4. Your typical voice command should include + – /  and x. Say, 10+23/3+6
  5. The app will then process the text.
  6. App shows result and  the numbers used.
  7.  It then speaks it 🙂
  8. Done


Right now, the app is not supported on firefox/opera, so you are out of luck if you use those exclusively . It its only supported on Chrome/Chromium. (less work for me!)

codarren @ hackers  dot mu

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