Todd Bellows , I have read your post, here:
Is this what is missing from modeled digital pianos and why they sound artificial?http://www.speech.kth.se/music/5_lectures/askenflt/pianist.html
Various sound exampleshttp://www.speech.kth.se/music/5_lectures/sounds/sounds.html
First of all it is important to realize that the term "touch" probably is used with several different meanings. If a pianist is said to have a "beautiful touch," it may refer to the way a melody part is lifted above an accompaniment, or how certain notes in a chord are emphasized. This seems mainly to be a question of the timing and strength of certain notes relative to other notes, factors which have been shown to separate the artist from the amateur. But in certain connections, a "beautiful" or a "bad" touch can refer to the character of a single note at a given dynamic level, a topic which has interested prominent pedagogues and even created tensions between pianists of different schools.
Surprisingly, a strong candidate for part of the answer has nothing to do with the normal string motion. It is probably so that a characteristic percussive component ("thump") at the onset of the note plays a decisive role for the character of the piano tone. This "thump" is generated by the key as it hits the stop rail on the key frame. The impact shock excites the keybed (the supporting surface under the action), and partly also the soundboard and iron frame.
The significance of the "thump" sound is illustrated in sound example 8, in which the normal airborne sound of a grand piano and the sound of the string vibrations in isolation can be compared. The listener will probably agree that the normal piano sound as recorded in the room has a certain resemblance with the sounds in a blacksmith's shop. The string sound component on the other hand, lacks something of the interesting piano character, resembling a plucked string more closely than a struck one. Once these components have been identified, they are usually easy to distinguish in all piano tones.
The "thump-component" is undoubtedly excited differently depending on the touch and could be assumed to be characteristic of a pianist's way of playing. The importance of this component of the piano sound is further illustrated by knowing that the recognized piano manufacturers select the wood for the keybed with great care in order to achieve the right "thump" quality.
I found the post very interesting. My computer does not allow me to hear any sounds or observe any youtube stuff as it is a linux operating system, but I played my Yamaha P95 digital and the Yamaha acoustic 3 legged piano so quietly that neither piano sounded a note - nor was there a thump played from either piano as I played so quietly but the acoustic piano had a slightly gentler action than the digital piano.
Acoustic pianos and digital pianos are not remotely similar but both the acoustic piano and the digital piano are awesome for what they are.