KMouth
Type-and-say frontend for speech synthesizers
KMouth is a program which enables persons that cannot speak to let their computer speak, e.g. mute people or peoplewho have lost their voice. It has a text input field and speaks the sentences that you enter. It also has support for user defined phrasebooks.
KDE's type-and-say frontend for speech synthesizers. . It includes a history of spoken sentences from which the user can select sentences to be re-spoken. . This package is part of the KDE accessibility module.
How to install KMouth in Ubuntu
If you are on a supported distro, you can install the application through software center by clicking the below link.
If the above link not working, run the below command in terminal to install kmouth in Ubuntu
sudo apt install kmouth