Speakers work by connecting to a source, wires inside the speaker transfer signals and then an electromagnet produces vibrations that take the electricity and convert it into sound. The exact sound is dependent on the speaker, its size and the overall quality of the speaker.
The source someone connects a speaker to is something like a personal media player or a tuner. The wire responsible for transferring the signals is usually a copper material because copper easily conducts electricity. To ensure high quality and easy transfer of the different electrical impulses, gold connectors are common because these work well with copper for conduction.