flite1-dev binary package in Ubuntu Focal armhf

 Flite is a small fast run-time speech synthesis engine. It is the
 latest addition to the suite of free software synthesis tools
 including University of Edinburgh's Festival Speech Synthesis System
 and Carnegie Mellon University's FestVox project, tools, scripts and
 documentation for building synthetic voices. However, flite itself
 does not require either of these systems to run.
 .
 It currently only supports the English and Indic languages.
 .
 This extra package provides the flite static libraries
 and header files.

Source package