festival 1:2.4~release-4 (arm64 binary) in ubuntu bionic

 Festival offers a full text to speech system with various APIs, as well an
 environment for development and research of speech synthesis techniques. It
 includes a Scheme-based command interpreter.
 .
 Besides research into speech synthesis, festival is useful as a stand-alone
 speech synthesis program. It is capable of producing clearly understandable
 speech from text.