Hi and thank You for answering.
As I need Raspberry Pi for one thing mainly I want to known if it is possible(and best how).
The main idea is that older people can just talk by Raspberry Pi. But it must be a total voice control, in Polish language. For example if somebody says "connect with X (in Polish)" the Raspberry Pi under e.g. Linux will connect by app with "X", e.g. with Tox client on other side. The Raspberry Pi will ideally be connected to power nearly all time and eventually in case of power off will "by-self" turn in after back of power in that mode. On other side - after connecting to Raspberry Pi e,g, app Tox(by other Tox client) You can hear what is in flat - e.g. if elder people will fall - can just talk(or be heard without saying "connect to") that have problem and other can help.
Are there programs for that? Which? Maybe You known which class of microphone should be suitable for that? Which Raspberry Pi would be best for that role?