Controlling the Vibrations
The damper controls the damping, or stopping, of the string's vibration. Dampers are found on most, but not all strings on the piano. The extreme treble strings do not generate as much sound as the longer strings, and do not use dampers. The damper is made of several parts, but the most important piece is the damper head - a small wooden block with a felt pad (or pads) attached to the bottom. When at rest, the damper head and felt rests directly on the string, effectively muting any string vibrations.
When activated, the damper is raised from the string, allowing the string to vibrate. Each key controls its own action and damper assembly - when the key is depressed by the pianist, the felt pad on the back of the key raises the damper lever, which rotates on the damper flange. As the lever rises, it raises the damper wire, which is held in place by the damper guide rail. The wire lifts the damper head with its felt pad from the string, allowing the string to vibrate. The upward motion of the damper is stopped by the felt pad on the bottom of the damper stop rail. When the key is released, the damper head is lowered back onto the string, stopping the sound. When the damper is at rest, it sits on a felt pad attached to the damper lever board. The resting height of the damper can be adjusted with the damper lever regulating screw.
The dampers can also be activated by the pedal – when the damper pedal (far right pedal) is depressed, it lifts all the dampers from the strings, allowing all the strings to vibrate freely. Even
strings which have not been struck by the hammer will vibrate sympathetically with those that have.
Follow the link for more information on the pedals…