Question

How did people use a telegraph to communicate without speech?

Answer 1

They were sending electric impulses that could be coded according to their duration to form the Morse Code.

Answer 2

Explanation:

With morse code people use a telegraphic mode of symbol to communiacte even without uttering any word. this is a technique that used sound tappings and it was without speech. the content data got transmitted as a progression of on-off tones, snaps and lights which which could be comprehended and analyzed without any special gear.  It is named after Samuel F. B. Morse. The code sign are either in letter or numeral or a prosign.