No, you cannot use just one wire from a standard telephone cord to transmit sound waves from point A to point B. Sound waves are mechanical waves that require a medium, such as air or a solid material, to propagate. A single wire cannot effectively transmit sound waves over a distance.
In a standard telephone cord, there are typically multiple wires enclosed within the insulation. These wires are used for different purposes, including transmitting audio signals and providing power to the telephone device. The audio signals are typically transmitted using a pair of wires known as a "twisted pair." This configuration helps reduce interference and cross-talk between the wires.
To transmit sound waves effectively, a complete circuit is required. In a telephone system, the audio signals travel through the twisted pair of wires in a balanced manner. The electrical signals representing the sound waves are generated at the sending end, transmitted through the wires, and then converted back into sound waves at the receiving end.
Using only one wire from a telephone cord would break the circuit and prevent the transmission of sound waves. It would not provide the necessary pathway for the electrical signals to travel, resulting in no sound transmission between point A and point B.