Generate speech from dynamic text field

Hi All,

I've been trying to find a way to generate text-to-speech (with realistic voices and not robotic) from the dynamic text fields I have in my app.

I need to be able to generate it from the textbox as I have random numbers displaying from a variable.

Does anyone know of an extension I can use?

(The extension can't be installed on a user's computer. It needs to all be contained when I publish it)

Thanks,
Jack