Tone quality is also affected by forcing the remaining two strings being struck to make contact with a part of the hammer felt which is not often hit (due to the whole action being shifted); this results in a duller sound, as opposed to the bright sound which is usually produced (due to the felt being hardened from regular use).
On most upright pianos, the soft pedal operates a mechanism that moves the hammers' resting position closer to the strings.
Digital pianos often additionally use this pedal to modify non-piano sounds such as the organ, guitar, or saxophone in ways appropriate to those instruments' playing techniques.
Pitch bends, Leslie speaker speed, vibrato, and so forth can thus be controlled in real-time, analogous to the "modulation wheel" on a synthesizer.
When used as a verb, soft-pedal refers to the toning down, damping, muting or obscuring of a thing; it means to proceed in a less forceful, circumspect or subdued manner.