Thanks to everyone for replying back to my question.
It is now clear that there is some delay even though as human that delay is not perceivable and may seem instantaneous.
It is also clear that electron from one telephone doesn't travel from one telephone to another but the disturbance or...
For my question let us just consider two telephone (POTS) connected by wire, junction boxes, several telephone switches/exchanges etc without any wireless connection. One telephone is in continent A and other is in continent B. I understand how sound is converted into electric current by a...