Physics question please explain?

Question

Children Sometimes play with a homemade "telephone" by attaching a string to the bottoms of two paper cups. When the string is stretched and a child speaks into one cup, the sound can be heard at the other cup. Explain clearly how the sound wave travels from one cup to the other.

Answer 1

Yeah.... what Heinz said. The energy travels along the string in waves, just like they do through the air.

Answer 2

A taut piece of rope will vibrate like a solid rod when exposed to a vibration (of the voice).