Report on "The Recorder"

I've decided to make a tranducer.
The original idea came from how when a train moves along the metal rails. Even from the otherside of the platform you can hear the violent shaking and the sounds of the train arriving moving towards you. That isnt a tranducer, but the friction between train and metals rails converting into sound and kinetic energy, and the rest is dispersed along the metal rails (the movement/shaking metal rails.)

Conclusion = tranducer machine to 'convert one energy into another form' to record a certain data.

Question= What to record
Ideas;

1. Record the vibration/sound of the buildings when a train arrive.

• Different distances, approaching, directly on top and leaving.
• Detailed time record when these train travels across these bridges
• In mm of the vibration of the building
  
• With these record i will be able to find out the frequency of trains passing by