Is it possible to custumize default voice in asterisk?

I like to know if is possible to custumize asterisk with your songs default.
For exemplo:

Google translator speak all the words digited on your website compund words.

does asterisk accept some things simlar with your letter available by default in /var/lib/asterisk/sonds/en or in other language in my case pt_BR (português Brasil)?
i have all letter and numbers from alphabeto song only in 1 letter,one at a time, how: a,b (be),c,d,e,f,g,
i have too some phrase ready create by default asterisk.

is it possible compound some phrase in the asterisk with alphabeto songs, exemplo:
i get song of letter W, E, L, C,O,M,E and compund the word Welcome, is it possible?

I hope so!
Thanks so much everybody

sorry for my bad english…

You can record your own phrases, but they must be one to one replacements for the English phrases.

For things like numbers, there are facilities to apply grammar rules.

I’d be surprised if PT_BR translations didn’t already exist.

You should carefully check the terms of use for the Google speech API. I would not be surprised if there was a ban on recording the results for this sort of usage.