[Tts-project] TTS plugin ivona or other

[olle at nordic-evolution.com]

Hi!
I have developed a product for visually impaired (nordic-evolution.com) 
and using debian 10 (buster) on a aarch64 ARM Cortex A-53. Today I use 
the default espeak via speech-dispatcher. I need a better TTS. I have 
managed to change to Festival via the 
/etc/speech-dispatcher/speechd.conf

I have changed the speechd.conf to this (it works):
AddModule "festival"                 "sd_festival"  "festival.conf"
DefaultModule festival
I need also to start the Festival service: festival --server

In speechd.conf there are other TTS, like the ivona (#AddModule "ivona"  
                   "sd_ivona"     "ivona.conf")

I want to change the TTS to a better more realistic one. I don't know 
how to install ivona, can't find any package. I need a good voice for 
Swedish, English and Norwegian. The ivona fullfill that!

Please give me some advice
Have a great day!
Best Regards
Olle