OpenVokaturi is the open-source version of the Vokaturi library and is distributed under the General Public License (GPL). OpenVokaturi may be appropriate for you if your app is in the stage of testing and development. With OpenVokaturi you can also distribute your app to your customers, as long as you do this under the GPL, which basically means that you make the source code of your whole app freely available. OpenVokaturi can be downloaded freely from our website, both as machine-code libraries and as source code.

Vokaturi emotion recognition software
The Vokaturi software can understand the emotion in a speaker’s voice just as well as people can.
What is Vokaturi?
Emotion recognition by speech
The Vokaturi software reflects the state of the art in emotion recognition from the human voice. Its algorithms have been designed, and are continually improved, by Paul Boersma, professor of Phonetic Sciences at the University of Amsterdam, who is the main author of the world’s leading speech analysis software Praat.
ARE YOU HAPPY, SAD, ANGRY OR COOL?
Vokaturi can measure directly from your voice whether you are happy, sad, afraid, angry, or have a neutral state of mind. Currently the open-source version of the software chooses between these five emotions with high accuracy, even if it hears the speaker for the first time. The "plus" version of the software reaches the performance level of a dedicated human listener.
Inviting all developers
As a developer you can easily include the Vokaturi software as a library in your own applications. You can choose between a free open-source license and a paid license.
What makes Vokaturi unique?
What makes us unique
Vokaturi emotion recognition can be easily integrated into existing software applications.
Our software has been validated with existing emotion databases and works in a language-independent manner.
The Vokaturi software is available as a drop-in library for most modern platforms, including iOS, Android, Windows, MacOS, and Linux.
Vokaturi B.V. is driven by:
Paul Boersma - expert in speech analysis software
Johnny Ip - expert in information management
Ton Gojani - coach and human behaviour specialist
Alexander Heijnen - innovator and expert in public safety & security
Hans van der Holst - legal & financial advisor
Robin Gojani - business developer
The right license for you
Vokaturi maintains three separate versions of its software library for recognizing emotions. You can choose which one to use in your app.
License type | OpenVokaturi | VokaturiPlus | VokaturiPro |
---|---|---|---|
Summary | OpenVokaturi is the open-source version of the Vokaturi library and is distributed under the General Public License (GPL). The library provides the analysis of the basic emotions and can be used in your app for staging / testing purposes (and for distribution, if you publish the source code of your app under the GPL). You can freely download OpenVokaturi from our website, both as machine-code libraries and as source code. | VokaturiPlus is the closed-source version of the Vokaturi library and allows usual commercialization methods (i.e. closed-source distribution of your app). VokaturiPlus measures the basic emotions, makes use of advanced deep learning techniques, and has a higher accuracy rate than OpenVokaturi. | If you need to train Vokaturi's networks for your own emotion-related classes, such as customer satisfaction, willingness to buy, customer retention, or first-time fix rate, you can obtain VokaturiPro. Vokaturi provides dedicated support with the application of the trainable Vokaturi library in your project. |
Cross-validated accuracy on the five built-in emotions | 66.5 percent | 76.1 percent | 76.1 percent |
Extendable to other emotion-related classes | |||
Classification method | 9 features plus three-layer network | Deep learning techniques | Deep learning techniques |
Source code | Open | Closed | Closed |
Pricing | Free | Paid | Paid |
License | GPL | Contact us | Ad hoc |
Legal to use in your closed-source apps | |||
Availability of API and libraries | iOS, Android, Windows, MacOS, Linux, Raspberry Pi, Odroid | iOS, Android, Windows, MacOS, Linux, Raspberry Pi, Odroid | iOS, Android, Windows, MacOS, Linux, Raspberry Pi, Odroid |
Availability of source code | |||
Availability of demo app code | |||
Support | Community | Dedicated | Dedicated |
Download now | Contact us | Contact us |
- OpenVokaturi license details
- VokaturiPlus license details
If you need more commercialization options for your app than OpenVokaturi can provide, for instance if you do not want to distribute your app’s source code, you can obtain VokaturiPlus, the paid version of the Vokaturi library. VokaturiPlus has a higher emotion recognition rate than OpenVokaturi; this difference may be another reason for you to opt for VokaturiPlus.
- VokaturiPro license details
If you need to train Vokaturi's networks for your own emotion-related classes, such as customer satisfaction, willingness to buy, customer retention, or first-time fix rate, you can obtain VokaturiPro. Vokaturi will provide dedicated support with the application of the trainable Vokaturi library in your project.
Stay up to date!
We regularly provide updates to our software for improved emotion recognition accuracy and new features.
Click here and sign up to our newsletter to receive these updates!
Change the future with us
Send us an email for more information and partnership opportunities
Contact us now