The phone, the great-grandfather of VoIP, has come a long way since the days of Alexander Graham Bell. The electric device designed to transmit speech — that is, the telephone — came about from Bell's desire to improve the telegraph. In the mid-1870's, the first phone was born when Bell proved that different tones could vary the strength of a current in a phone wire. To create the telephone, Bell invented a working transmitter with a casing capable of receiving various electronic currents and a receiver which reproduced the variations in frequency.