Electrical Engineering for Everyone
The Digital Revolution in Telecommunications
S1 E6:
In the old-style analog telephone system, voltage increased and decreased across the wires, corresponding to the human voice signal. But in a digital system, that all changes. Learn how the human voice is changed into binary values, sent over the system, and then converted back into volts with the voltage applied to the speaker in the phone handset. The human ear takes it from there.