I had heard years ago that the sound the the blasters in the Star Wars universe was achieved by hitting taut steel cables and recording the resulting noise. This seems to be confirmed by this video:
This guy does something similar with a Slinky tensioned only by its own weight (mic affixed directly to Slinky):
Can someone explain the physics at work here? Why does the pitch heard at the microphone start high and rapidly decrease? What parameters determine the starting pitch and the time-rate-of-decrease?
WAG: the cable is tighter at the anchored ends and the wave gets dampened out as it travels toward the looser middle.
I’ve heard it myself from utility pole guy wires.
There’s several different things going on at the same time.
The initial loudish one is the sound of the strike travelling through the air directly to your ear. Then there’s the reverberation as the sound travels the length of the cable in one direction and then the next (in mostly a transverse fashion, but there is also a longitudinal wave). The reason it seems to raise and lower in pitch is due to the Doppler effect: lower as the sound wave rushes away from you and higher as it rushes towards you.
The sound behaves similarly to how the slinky moves in this demonstration.
The same effect is happening in a stringed instrument, but the length of the string is short enough that the reverbs are so close together as to become one sound in your ear.
