This timeline or mind map show what’s telecommunication from 1845 to 1995. Just not about deaf and hearing culture and this how telecommunication help them to have contact and conversation with any reasonable because they need to know how to read or write that matter what happen if no one teaches them.
This show it work for communication use. example: the video show about shoes how she can buy kind of shoes by use old object like typewrite and write the letter. Today , she can order the shoes by computer and networking.
Text telephone (TTY) 