This is interesting. Some messages were sent to outer space expecting a response.
A committee headed by astronomer, author, and space exploration advocate, Carl Sagan, designed and selected the Voyager's message. It is inscribed on a 12- inch gold-plated copper disk and contains sounds and images expressive of life on Earth and the best of human culture and civilization.
This includes a greeting in 55 different languages, from Aramaic to Vietnamese. We listened to a child's voice in English say "Hello from the children of Planet Earth", and a Spanish speaker saying, "¡Hola y saludos a todos!"
The record also includes a compilation of great music from blues to Bach to ragas, and a sampler of non-human Earth sounds such as wind, rain, surf, chimps, sheep, crickets, saws, and trains. We browsed some of the photographic images the Voyager carries electronically -- simple depictions of essential human knowledge including maps, diagrams of DNA, vertebrate anatomy charts, chemical and mathematical definitions, and other visual displays.
No takers yet!