tl;dr: The concept is a lightweight markup based on how people talk in instant messaging or IRC. This is unlike markdown’s source of influence, which is more based on emails and forum posts.
Just a thought:
There is already a speech synthsis markup language call SSML: http://www.w3.org/TR/speech-synthesis/
However I do wonder if there is a need to perhaps consider what a markdownish speech synthesis markup language may look like. I don’t think you can exactly use commonmark/markdown syntax to do speech synth. Take for example sarcasm, you can’t exactly do it in pure text markup.
So far what I can think of:
...– indicates pause in speech
*– can be used to ephasis words in speech
\<switch>– at end of the line indicates how entire sentence should be carried out
You must reallly love to be a good guy /s
"scare quotes"– Or maybe sarcasm is better done as scare quotes
"around the sarcastic expression?
:D– emotion icons can perhaps be used to indicate previous statement should be carried out in a certain tone. e.g.
This really doesn't make me feel good D:
--> #id <--– Allows the speaker to ‘point’ to a particular section in a page?
Since this is more conversationally based markup language. This could be useful in terms of creating a lightweight conversational markup language that would work well in instant messaging or IRC. So in general, this speech markup language should aim for speed of writing.