I was seven years old, in '77, and fascinated with the space program especially the Voyager missions. Of particular interest to that early me was the gold-plated audio-visual disc on both Voyager 1 and Voyager 2 that contained the sights and sounds of our world intended for intelligent life. From The Atlantic is a fascinating article about one reporter's attempt at
Solving the Mystery of Whose Laughter Is On the Golden Record.