Text to speech on my Macbook Pro laptop is not working but it does work on a PC. Are there known issues with this library on a Mac?
There are some issues with recording sound in Mac (see https://github.com/jmoenig/Snap/issues/2566 ). But I do not know about Text to Speech. By the way, welcome to the forums!
I think it depends what browser you're using. Some of them haven't implemented tts. Try Chrome; they're usually the quickest to add features.