[CAUT] Semantics

[Steve Fujan]

This whole discussion about the soundboard being an amplifier or a
transducer is quite interesting.  Here is how I have become comfortable with
the difference.

A megaphone is: "A funnel-shaped device used to direct and amplify the
voice."  You speak into one end of a megaphone, and the sound is amplified
when it comes out the other end.  Clearly, a megaphone is a sound amplifier.

There is another, more modern device called a bullhorn which is: "A portable
device consisting of a microphone attached to a loudspeaker, used especially
to amplify the voice."  Clearly, the bullhorn is also a sound amplifier.

But the bullhorn consists of several components.  The first of which is a
microphone which transforms the input sound into an electrical signal.  The
microphone is a transducer.  Then the bullhorn has an amplifier that uses
battery power to amplify the electrical signal coming from the microphone.
And finally, the bullhorn has a loudspeaker that transforms the amplified
electrical signal into louder sound.  Overall the bullhorn is a sound
amplifier, but it has sub-systems we can call transducers and an amplifier.

Let's now visualize the piano as having three subsystems as well.  First is
the "action", which I will define for this discussion as everything from the
keys to the hammers.  Second is the string.  And the third is the soundboard
system.  When the pianist pushes a key the action transforms that effort
into vibration of the string.  The string vibrates.  The soundboard then
transforms some of the vibration of the string into sound output.

The string does generate a small amount of sound output all by itself, but
that is not the majority of what we hear, and is not what the soundboard
transforms into sound.

So, visualizing the action as a transducer that transforms the pianist's
effort into vibration of the string, and the soundboard as a transducer that
transforms the vibration of the string into sound, there is no "amplifier"
in the system.

This has helped me to keep straight some of the technical details, and I
hope it will help some of you as well.

Best Regards,
Steve

Definitions courtesy of The American Heritage® Dictionary of the English
Language, Fourth Edition
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