This Keyboard Maestro macro allows you to select text, invoke a keyboard shortcut (or another Keyboard Maestro trigger that you select) and have Siri speak the selected text. In this case, the voice selected is for French but is easy to change this (and the speed) in the “Speak Text” action if desired.
It simply copies the current text to a named clipboard then reads that clipboard aloud.
(If you are looking to change this to another language, you can find the name of the speaker you want by going to System Preferences -> Accessibility -> Speech and clicking on ‘Customize…’ in the ‘System Voice’ dropdown.)
To use, download the zipped file below, unzip it, and import the resulting file into Keyboard Maestro using File –> Import Macro.