Apple’s built in text-to-speech can be a useful tool, or just a lot of fun for pranks. This can be triggered via Terminal. When you go and open Terminal (found in the Applications > Utilities folder) you get a blank screen with a blinking cursor. Type say “what you want you Mac to say” and your Mac will speak to you. And you didn’t even have give it a treat!
The say command has options like change its voice to something different. To see the options available in your OS, navigate to System Preferences > Dictation & Speech > Text to Speech and there is a menu with all of the available System Voices. To choose a voice in Terminal type: say -v “Voice Name” “what you want your Mac to say”
You can also export the voice clip as audio file. To do this use -o and specify the file path. The command would look like this: say “Hello World” -o hello recording.aiff
For more info type the following command into Terminal: man say