On this old thread, some new life:  I recently ran across an item in my Google feed declaring that it has now been proven and demonstrated by a Japanese researcher how a pianist can alter the final sound of an acoustic piano AFTER the hammer is launched, a debate that's been persisting for decades and decades.  Here's the link:

Source: ScienceDaily
https://share.google/BwDh6Y4MyLk4oRFol

I then asked an A.I. agent to teach me why this is now proven as possible/the new gospel.  Here is the explanation:

"Your skepticism is completely justified by classical physics. Traditionally, scientists argued that because of the escapement mechanism, a pianist completely loses physical contact with the hammer right before it strikes the string. Therefore, the only thing a pianist should theoretically control is the hammer's final velocity (volume). [1, 2]

However, the groundbreaking study led by Dr. Shinichi Furuya used high-speed sensors to prove that a pianist's specific touch alters the piano's timbre through three micro-mechanical mechanisms that occur before and during the note: [3, 4]

1. Acceleration at Escapement (acc-escapement):

The most significant finding is that the way a key accelerates up to the exact moment of escapement fundamentally dictates the behavior of the hammer. [4, 5]

The Physics: The hammer assembly is not perfectly rigid; it can experience microscopic flex and vibration depending on the force profile applied to the key. [6]

The Result: A sharp, stabbing acceleration forces the hammer to detach differently than a smooth, pressing acceleration. This subtly impacts the exact angle, surface area, or micro-vibration of the felt hammer when it collides with the string, altering the harmonic spectrum (timbre) independent of final velocity. [4, 5, 6]

2. Initial Strike Velocity and Touch Noise (onset-noise):

The total sound we perceive as a "piano note" includes the acoustic strike itself. [7]

The Physics: A struck touch (lifting the finger and hitting the key surface) vs. a pressed touch (keeping the finger resting on the key before pushing down) creates radically different impact profiles. [6, 7]

The Result: Hitting the key creates a mechanical "thud" or high-frequency transient sound at the surface of the ivory/plastic, which bleeds into the initial sound profile. Highly trained pianists manipulate this onset noise to create "hard" vs. "soft" timbres. [6, 7]

3. Key-Bed Bottoming Noise:

Similar to the initial surface strike, the force profile at the very bottom of the key's travel changes how the wooden key frame vibrates. [7]

The Physics: A pianist can follow through aggressively so the key hits the key-bed cushion violently, or they can decelerate their finger mid-stroke so the key lands softly on the felt underneath.

The Result: This sound transfers through the piano frame and slightly modifies the background noise envelope of the vibrating string. [7]

4. Note Overlap and Hand Synchronization (overlap):

The study also pointed out that when playing multiple keys, the microscopic timing, alignment, and release overlap between consecutive keystrokes change how the soundboard accumulates resonance. [4, 8]

By mastering these microscopic variations, pianists can reliably project different tonal qualities—like brightness, weight, and clarity—without relying on the sustain pedal or altering the baseline loudness. [2, 9]

If you would like to explore this further, I can provide more details on how these techniques are taught or break down the differences between a struck and a pressed touch. [6, 10]

[1] https://www.e-musicmaestro.com
[2] https://pmc.ncbi.nlm.nih.gov
[3] https://www.sciencedaily.com
[4] https://www.neuropiano.org
[5] https://phys.org
[6] https://www.ncbi.nlm.nih.gov
[7] https://pmc.ncbi.nlm.nih.gov
[8] https://www.eurekalert.org
[9] https://datadryad.org
[10] https://pubmed.ncbi.nlm.nih.gov

"

all these points are indeed valid, however the only ones that affects individual sound produced by a key once the hammer has fully escaped is key bottoming noise (3) .  (1) & (2) happen before. 
(4) is different and affects the release portion of the sound and the sympathetic resonance but cannot be classified with the other points as from the moment several notes are played , the  context is different and  becomes part of expressiveness not only  touch.
It may be more consistent with other points to simply consider the acceleration profile of a key during release and its interaction with damper that changes individual end tail of the sound (5)

Source: ScienceDaily
https://share.google/BwDh6Y4MyLk4oRFol

I then asked an A.I. agent to teach me why this is now proven as possible/the new gospel.  Here is the explanation:

"Your skepticism is completely justified by classical physics. Traditionally, scientists argued that because of the escapement mechanism, a pianist completely loses physical contact with the hammer right before it strikes the string. Therefore, the only thing a pianist should theoretically control is the hammer's final velocity (volume). [1, 2]

However, the groundbreaking study led by Dr. Shinichi Furuya used high-speed sensors to prove that a pianist's specific touch alters the piano's timbre through three micro-mechanical mechanisms that occur before and during the note: [3, 4]

1. Acceleration at Escapement (acc-escapement):

The most significant finding is that the way a key accelerates up to the exact moment of escapement fundamentally dictates the behavior of the hammer. [4, 5]

The Physics: The hammer assembly is not perfectly rigid; it can experience microscopic flex and vibration depending on the force profile applied to the key. [6]

The Result: A sharp, stabbing acceleration forces the hammer to detach differently than a smooth, pressing acceleration. This subtly impacts the exact angle, surface area, or micro-vibration of the felt hammer when it collides with the string, altering the harmonic spectrum (timbre) independent of final velocity. [4, 5, 6]

2. Initial Strike Velocity and Touch Noise (onset-noise):

The total sound we perceive as a "piano note" includes the acoustic strike itself. [7]

The Physics: A struck touch (lifting the finger and hitting the key surface) vs. a pressed touch (keeping the finger resting on the key before pushing down) creates radically different impact profiles. [6, 7]

The Result: Hitting the key creates a mechanical "thud" or high-frequency transient sound at the surface of the ivory/plastic, which bleeds into the initial sound profile. Highly trained pianists manipulate this onset noise to create "hard" vs. "soft" timbres. [6, 7]

3. Key-Bed Bottoming Noise:

Similar to the initial surface strike, the force profile at the very bottom of the key's travel changes how the wooden key frame vibrates. [7]

The Physics: A pianist can follow through aggressively so the key hits the key-bed cushion violently, or they can decelerate their finger mid-stroke so the key lands softly on the felt underneath.

The Result: This sound transfers through the piano frame and slightly modifies the background noise envelope of the vibrating string. [7]

4. Note Overlap and Hand Synchronization (overlap):

The study also pointed out that when playing multiple keys, the microscopic timing, alignment, and release overlap between consecutive keystrokes change how the soundboard accumulates resonance. [4, 8]

By mastering these microscopic variations, pianists can reliably project different tonal qualities—like brightness, weight, and clarity—without relying on the sustain pedal or altering the baseline loudness. [2, 9]

If you would like to explore this further, I can provide more details on how these techniques are taught or break down the differences between a struck and a pressed touch. [6, 10]

[1] https://www.e-musicmaestro.com
[2] https://pmc.ncbi.nlm.nih.gov
[3] https://www.sciencedaily.com
[4] https://www.neuropiano.org
[5] https://phys.org
[6] https://www.ncbi.nlm.nih.gov
[7] https://pmc.ncbi.nlm.nih.gov
[8] https://www.eurekalert.org
[9] https://datadryad.org
[10] https://pubmed.ncbi.nlm.nih.gov

"

I could almost swear that the keyboard really got heavier in such days...   Incredible how our minds trick us.

Maybe a slider adjust for our brains would be a god idea...    ;-)

Right, but it also works the other way - if the pianist feels 'good' or 'in control' using a particular technique, they will play better - so in that sense the overall performance can sound better because it actually is (regardless of whether a note in isolation would sound different).

I absolutely agree because I have noticed this myself.  There are times when my DP sounded just wonderful and it was inspiring, whereas at other times it sounded ordinary at best and I wasn't inspired.

The sound of the piano never changed one bit, but my perception of the sound did, and when it sounded better, I was more inspired and played better.  And of course, I was able to coax more nuances out of it.

That's why I say pianists aren't being dishonest when they claim to hear differences.

For all the intelligence of the human brain, it can be fooled quite easily.

Glenn

People belived they could get a half bit comand if move the joystick specially.

I don't think that these pianists are being dishonest - they truly believe they have control over the tone by varying the strike method.

Emotions are a powerful influence on our perception.

Right, but it also works the other way - if the pianist feels 'good' or 'in control' using a particular technique, they will play better - so in that sense the overall performance can sound better because it actually is (regardless of whether a note in isolation would sound different).

BTW although I have no experience of this issue as I'm not classically trained, it reminded me of the first games console, the black & white 'Pong' game:

If you don't remember it, it was a simple kind of table tennis, with a white square ball bouncing around that the players had to deflect with their 'paddles' (vertical white bars that they could move up or down).

Players frequently convinced themselves (myself included) that they could apply 'spin' to the ball by moving their paddles during ball contact - but the software didn't take that into account at all.

True, but what would be the point of emulating this kind of noise?

I agree completely, Glenn. Besides, these noises are probably inaudible from an audience perspective anyway. So no need to include them in any model, they won't be missed

If Pianoteq would emulate this extra "brand" of noise, would require a special controller, able to differentiate those different touchs with same velocity.

True, but what would be the point of emulating this kind of noise?

What's next - emulating the sound of someone in the audience coughing or sneezing?

The truth is, if piano builders could have gotten rid of the damper and key noise from acoustic pianos, they would have.

But unfortunately, the "perfect piano" is a mechanical contraption with thousands of pieces that emit squeaks, rattles, thumps, and clacking noises.  And this is without the sound of the pianists fingers hitting the keys.

Glenn

I would guess that finger-key noise really depends on the physiology of the player's fingers.  Some people undoubtedly have more padding on the fingertips that would make the impact less audible.  I myself have rather bony fingers, so on a good staccato or fast run, the sound of fingers hitting the keys is probably mixed into the overall sound, but I rarely notice it.  What I mostly notice is sore fingertips after playing lots of Rachmaninoff, etc.

It probably also depends on the weight of the action.  A light action is more likely to give way more at the moment of impact, making the impact less audible.

On the other hand, is the noise of a finger hitting a key considered to be an important part of piano sounds?

Since only "some" professional pianists could tell the difference, this might suggest that the finger noise is not an important characteristic of piano music.

I have never been able to detect this noise when playing, and usually I don't even notice the sound of the key hitting the key bed on an acoustic piano.  On my digital with the sound turned off I can hear the keys hitting the key bed, but I still don't notice the sound of my finger hitting the keys.

Can anyone else detect the noise of the finger touching the keys?

Glenn

Glenn

So if someone wanted to add this extra "dimension" to their performance, why not put a physical microphone pointing on your hands to record the finger noise, and mix it with the Pianoteq sound? Electric guitarists are doing the same thing - their main sound is coming from a miked amp or an amp simulator - but they sometimes add an extra microphone just above the strings, to have some extra attack and pick noise to mix to taste.

I don't understand... 

WHat's the difference about acceleration to the strike effect, if the important thing is the final veloccity when the hammer strike the strings?

As far as I'm concerned - nothing.

But the second reference was comparing hitting a key with the finger and driving the hammer onto the strings compared to starting with the finger on the key and pushing down to achieve the same hammer velocity.

In the first case, there is a slight noise of the finger hitting the surface of the key.   It must be very small, but it is a noise, and although not very musical (wink, wink), it is a noise that some highly attuned pianists can hear.  So when these pianists did a listening test, they could hear the finger strike the key, and thus know the key wasn't "stroked".

What we might gather from this is - although some pianists can tell the difference between the sounds generated, the noise of the finger hitting doesn't really make the resulting sound softer.

In reply to Chris's last post, there are times when I play the piano, that it sounds much better, I play better, and I am more creative in my arrangements.  At least that's the mood I'm in, so I really believe that I'm better.

However, last night I was listening to some stuff I recorded six years ago that I should have discarded.  But I was now listening to the midi file being played by Pianoteq, rather than my first Roland.

Guess what? - those recordings I nearly tossed sounded wonderful to me.

We are all affected by things in our head, and we hear things because we feel them.

I don't think that these pianists are being dishonest - they truly believe they have control over the tone by varying the strike method.

Emotions are a powerful influence on our perception.

Glenn

WHat's the difference about acceleration to the strike effect, if the important thing is the final veloccity when the hammer strike the strings?

I scanned the third reference, and they concluded that note G5 had some discernible differences - which doesn't surprise me when I think about it.

The upper treble sounds on an acoustic grand are weaker and extraneous noises become more apparent.   I'm referring to the noise of the key hitting the key bed.  I have a friend (mentioned on this site previously) that is an excellent pianist, and who operates a business restoring pianos.  We often talk of these things - how sound is produced, propagated, and heard.  Incidentally, he doesn't believe in the concept either.

On several occasions he has had a grand piano with the strings removed, and we have "played" the keys.  The sound of the key hitting the key bed is quite loud, but it is constant throughout the full range.  And I might add, resonates into the soundboard.

However, in the upper treble with smaller, shorter strings, where the sound is less robust, this key bed noise is a greater part of the overall sound than it is in the lower notes.

Add in the noise of the finger contacting the key surface (which doesn't occur when the key is stroked or with the finger starting on the key), and it seems that there should be a discernible difference between high and low notes.

An interesting finding/statement in the Conclusion of this third report is, ". . . however, it is in a much lesser degree than most pianists expect".

I could concede that there is a slight difference, but isn't the most important question:  "Is is the difference significant"?  If it's not significant, then why do we keep fooling ourselves?

This belief is extremely hard to dispel because pianists have believed it and practiced it for centuries - and the belief is still being taught at otherwise credible music schools.

The third study was done in collaboration with a pianist that believes in the concept - if I had conducted the tests, I would be hard pressed to write a conclusion that refuted what my collaborator believed.

Glenn