Touch and Vibration

[Richard Brekne]

Hi David

I think you can put Alexander Galembo right up there with Conklin,
Askenfelt, Weinreich, Wogram, Janson, Hall, and the rest of this group of
researchers. Indeed Dr. Galembo is doing a stint in Stockholm right now in
Aksenfelts company, tho I am not sure what he is working on or whether he
and Anders are up to something together. But this question of how (and I
dont say if)  pianist can feel the voice of the piano has fascinated him for
many years, and I recommend his articles to all technicians.

It was said recently that the only thing the hammer brings to the string is
its momentum and elasticity. I find myself questioning this. For the first
momentum is defined as inertia in motion, but the quantity says nothing
about whether this is increasing or decreasing. For the second, the hammer
(and shank) brings its own vibrational modes to the strings, which are
excited in different ways for varying types of touch and are delivered to
the string for the very short period of time the string and hammer are in
contact (three whole periods of string to aggraffe vibration at least). The
collision between the hammer and strings influence these modes further as
the hammer retreats from the string into check. These, along with the speed,
acceleration, force and other factors are like bits of information passed
back through the check into the key and finger.

There are two really interesting aspects to this. Number one, it does show
that there are quantifiable bits of information delivered by the hammer to
the finger at the key, as a result of both the touch used to set it in
motion, and from the hammers impact with the string. Secondly it shows that
at least in some small degree the excitation of the strings are not just a
result of the physical momentum of the hammer, but also a result of the
actual vibrational mode picture of the hammer which is in turn influenced by
the type of touch employed.


Definition of Haptic: Sense of physical contact or touch.

I liked the analogy of the basketball, as it seemed actually to have very
much in common with the case of feeling the impact between hammer and
string.



David Andersen wrote:

> >> One question in particular I would like your thoughts on.
> >It is said by some
> >> that pianists can feel at the keys with the fingers,  the
> >impact of the
> >> hammer on the strings. Do you have any studies that go
> >directly to this
> >> point ? And in anycase, what do you think of that
> >assertion ?
>
> Hey RicB----   I'm still thinking about this guy's answer---I'm not sure
> yet whether it's deep or BS---
> but please define the word "haptic," as in "haptic perception" and
> "haptic information."
>
> Thanks. Dude.
>
> David A.
> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives




--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html