flite software package provides Small run-time speech synthesis engine, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install flite
flite is installed in your system.
Make ensure the flite package were installed using the commands given below,
$ sudo dpkg-query -l | grep flite *
You will get with flite package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Sound |
| Package | flite |
| Version | 2.0.0-release-3 |
| Description | Small run-time speech synthesis engine |
| Sub Section | Sound |