The changes in the sound can also be caused by so-called ‘wear effects’ which means that the cloth and felt layers and also the wooden parts get worn after some time of use. The age, amount of usage and environment all affect the piano. Thus, the sound might become dull and the touch might feel a bit heavy.
Worn parts should be replaced or repaired and the action and keys regulated, so that the sound and touch will be back to normal.
Here in Hong Kong, due to high humidity levels, metal parts such as center pins, key balance pins etc are often found to be rusted and need to be replaced. Components from your piano may be temporarily removed and taken to my workshop. Parts will be repaired whenever possible, or replaced.
Occasionally it will be necessary to have the piano fully repaired. Restoration and repair can range from work on the piano action to full piano rebuilding to balance all the components of the piano.