I thought I would add a few comments to current discussions.  The first
thing is that I have never understood how, starting in 1913, Duo-Art
could use the loudness difference between the dampers on or off as the
foundation for all volume levels, while Ampico didn't discover it made
a difference until 1927.

The second thing is that I disagree with Craig Brougher's explanation
on sound curves (assuming that I understand it correctly).  Craig is
saying that if you graphed the power of a played note with and without
the sustain, the height of the curve in both cases would be the same,
but the decay time of the sustained note would be longer when the loud
pedal is on, so the area under the curve is a little greater and the
tendency of the ear to integrate that effect tells it the note is
louder, rather than equal but of longer duration (equally loud and
slower decay).

It seems to me that he is saying the volume is the same (the height
of the curve) but it is perceived louder because of the longer sustain.
I do not think that the area under the curves is of paramount
importance since the heights are the same.  Furthermore, the total area
under the curve measures the tone over time-people hear only an instant
at a time, and piano notes are the classic example of tones starting at
their loudest and going down from there.

I will agree that raising the pedal makes a piano sound louder for two
reasons: (1) The sympathetic vibrations of unstruck strings adds to the
volume, and (2) not having to lift a damper that is being held down
with springs and lead weights will make the key louder.

Randolph Herr

 [ Ampico didn't really admit that there was a problem!  Mr. Stoddard
 [ held patents which claimed to eliminate the need for a sustain
 [ pedal, by extending the note perforations approximately as the loud
 [ pedal would be used.  The music editors hated the practice.  (After
 [ all, that's an important characteristic of a piano!)  And of course
 [ the extended note slots weakened the paper.
 [
 [ Beginning in 1927 Ampico rolls were edited for better compatibility
 [ with the Ampico B system (the "New Ampico") and the practice of
 [ 'extending the notes' was quietly discontinued, to the great relief
 [ of the music editors.  The note extensions of some earlier
 [ 'evergreen' rolls also were deleted when they were re-edited for
 [ the Ampico B.  Reference the interview with Angelico Valerio in
 [ "The Ampico Reproducing Piano," ed. by Richard J. Howe, publ. by
 [ MBSI, 1987.  -- Robbie