Over time, the felt on the wool hammers becomes compacted & grooved from repeatedly striking the high-carbon steel & copper strings, which can cause the piano to sound harsh, bright, or uneven.

Piano voicing is the process of adjusting this tone & quality of a piano’s sound by modifying the firmness & density of the felt on the hammers.

Specialized voicing techniques include:

1. Needling: Using a tool with fine needles to puncture & loosen tight wool fibers in the hammer felt, which softens the tone.

2. Reshaping or Filing: Shaving or sanding grooved or flattened hammer heads to restore their original shape & create a cleaner strike.

3. Lacquering: Applying a hardening solution to the felt of the hammers to harden them, producing a brighter, more powerful tone.

For more information about voicing & regulation, visit here.