Why Doesn’t Pressing After Key-Bottom Make a Note Louder?

When a key has reached the bottom and the note still seems too soft, adult learners often keep pressing, as though more force could be added to a sound that has already begun. That is not how the acoustic process works. The finger moves the key, the action transfers that motion to the hammer, and the hammer leaves the mechanism before striking the strings. The main loudness of the piano tone depends on the speed of that impact. By the time the key reaches the key-bed, the decisive movement has already occurred. Extra static pressure cannot catch the hammer and make the same note louder.

This does not mean that touch is irrelevant. Experiments show that pressed and struck touches can use different bodily movements to produce similar loudness. A separate perception study found that, even at the same hammer velocity, mechanical sounds from finger–key contact and key-bottom impact can help listeners distinguish forms of touch. Those sounds affect the complete auditory and tactile experience, but they do not show that sustained pressure after key-bottom increases the strings' vibration.

When practising a loud chord, place attention on what happens before key-bottom: how the arm organises speed, whether the notes arrive together, and whether the sound is clear. After the sound begins, a finger may remain in contact when the note must be held, but the forearm need not keep driving weight into the key-bed. Research on loud keystrokes also suggests that pianists use follow-through movements after depression to absorb impact. The central point is simple: loudness comes from controlled motion, not from bracing at the bottom of the key. Releasing unnecessary pressure leaves room for the next movement.

https://pubmed.ncbi.nlm.nih.gov/17550193/
https://pubmed.ncbi.nlm.nih.gov/25373983/
https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2020.01159/full

When comparing pre-impact speed with post-impact release through repeated short chords, <a href="https://apps.apple.com/us/app/scoreflow/id6796205656">ScoreFlow</a&gt; can accompany the work as a piano learning and practice app; sound and bodily sensation remain the test, not how long you press at key-bottom.