Funny , one of our user made a similar app on Webshell.io mixing Twitter API and tts (Text To Speach) API,

http://webshell.io/editor/thyb/ttsTweet

(you need to Github connect before to access his repo, then click on run, then Twitter connect of course for your own feed)

If you don't want signup or connect: You can also try directly the script in the console tour at the bottom of http://webshell.io homepage by copy pasting

fs.thyb.ttsTweet();