Dhvani can help not only blind users but also dumb users. I will explain how dhvani act as your mouth using KMouth.
Kmouth is as KDE Accessibility Appllication and it act as a test to speech front end. KMouth is a program that enables persons that cannot speak to let their computers speak. It includes a history of spoken sentences from which the user can select sentences to be re-spoken. It learns the words the user wrote and have autocompletion. It also includes a phrasebook, using that you can store the commonly used phrases for quick access.
We will see how dhvani can be used with Kmouth.
open KMouth : KMenu->Utilities->Accessibility->Kmouth. Install it if not already installed
You will get configuration window and give the “Command to speak text” as dhvani %f
Done. Now you can type some text in the Kmouth and ask it speak.
To avoid typing the words that are used often, create a Phrasebook. Refer KMouth Help document for that. You can also add a wordlist so that you will get autocompletion feature while typing words. Refer Kmouth Handbook for that also. It is easy and just a matter of giving some text file to learn.
I hope it will be helpfull for the dumb users even though there are some practical problem like keeping the computer with them…
For for information about dhvani, how to install etc see the documentation