Pressing a key on a piano’s keyboard causes a felt-covered hammer to strike a steel string. The hammer rebounds, allowing the string to continue vibrating at its resonant frequency. This vibration is transmitted through a bridge to a sounding board that couples the acoustic energy of air. The greater the velocity with which a key is pressed, the greater the force of the hammer hitting the sting, and the louder the note produced. Similarly, a blow to the head causes movement of the skull. When the skull moves, the brain moves; when the skull moves suddenly and with force, the brain is forced up against the skull and compresses. The result of such incident is concussion. Concussion can result in heightened sensitivity to sound, and is often associated with the sound of circling, chirping birds. It is perhaps not surprising that a large object, for example a piano, falling from a height also produces its own sound, through the displacement of air. This sound is oddly reminiscent of the sound of a flute, or more precisely, a piccolo.

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