Likely Ubuntu Studio allows a good beginning.
https://ubuntustudio.org/
I prefer Arch Linux, but it's neither an audio distro, nor easy to
use for newbies.
Regarding the speech synth you should consider to get information from
blind Linux users. There are not that many visible impaired Linux users
subscribed to this list.
I don't know if the below links are useful.
http://leb.net/blinux/
http://www.tldp.org/HOWTO/Accessibility-HOWTO/visual.html
http://vinuxproject.org/
https://wiki.archlinux.org/index.php/TalkingArch