It was at Willcutt Guitar shop in Lexington, KY, that I saw the machine. I figured if they were using it, it must make some sense. Should have known you would have one, Kristi!
I've seen vibrating machines in guitar shops...kind of reminded me of those exercise belt things you sometimes see in cartoons....
Apparently it is only a myth that nervous people are thin because they shake so much they vibrate off all their fat. Some sure sing pretty, though! 
Personally, I believe that yes, instruments with wooden sound boxes will tend to sound better, more resonant if they are played a lot, as opposed to new or long stored instruments. The amount of change would naturally be quite varied....from almost nothing to something pretty noticeable...and depending on the listeners sensitivity as well.
I think the term myth implies that it is incorrect, whereas theory implies it's something that has yet to be proved right or wrong. So in this case I'd refer to it as a theory rather than a myth.
I agree that myth is probably not the best choice of words here. They don't call it 'tone' wood for nothing. I've had subtle but noticeable changes in tone from an instrument as it ages and the wood settles into its new configuration.
Brian -- thanks for those references. Looks like I've got some light reading ahead...
Personally, I believe that yes, instruments with wooden sound boxes will tend to sound better, more resonant if they are played a lot, as opposed to new or long stored instruments. The amount of change would naturally be quite varied....from almost nothing to something pretty noticeable...and depending on the listeners sensitivity as well.
I think the term myth implies that it is incorrect, whereas theory implies it's something that has yet to be proved right or wrong. So in this case I'd refer to it as a theory rather than a myth.
Hi Marg,
Yes, regular playing and aging of wood in music instruments does help create a more resonant tone, and it’s not the strings. Humidity and “creep” (a glue’s tendency to pull apart slowly when it is put under a continuous load) are believed to be mostly responsible. It is known that playing regularly in high humidity environments leads to a decrease in loss coefficient (the degree to which the wood dissipates vibrational energy via internal friction) and an increase in stiffness (Hunt and Balsan 1996). Evidence by Beavitt (1996) shows that creep facilitated by humidity cycling changes the overtone spectrum of an instrument, making it more resonant and more sonorous. Creep in newly strung instruments is accelerated by vibration absorption in the wood which is why you can help a new instrument settle in faster by playing it or exposing it (via those “blaring speakers” Ken mentions, for example) to those vibrations (Segerman 1996, 2001). It’s also been shown that the gradual loss of hemicellulose in wood (as it decomposes with time) lowers its density without affecting its Young’s modulus (one of the most important determinants of the acoustic properties of a material), which improves the sound radiation coefficient of the wood (another important determinant)(Bucur 2006). In fact, that understanding has led to some very interesting research in aging soundboards by deliberately infecting the wood with fungus to lower its density while keeping the Young’s modulus constant, again improving the sound radiation coefficient (Zierl 2005, Schwarze 2012).
Strings also have an effect on tone, depending on their material, age, etc. but they are not responsible for the sweeter sound of aged instruments, except insofar as if you are like me, and much prefer the warmer "deader" sound of old strings that have built up a layer of crud on them (from shed skin cells, oils etc) compared to the brighter sound of brand new strings. (And yes, I realize I'm in a very small minority here with that preference).
Hope that helps a little.
Kind regards,
Brian
HUNT, D. G., AND E. BALSAN. 1996. Why old fiddles sound sweeter. Nature 379: 681.
BEAVITT, A. 1996. Humidity cycling. Strad (Nov): 916–920
SEGERMAN, E. 1996. Wood structure and what happened in the Hunt & Balsan experiment. Fellowship of Makers and Researchers of Historical Instruments Quaterly 84, Communication 1471: 53–55.
SEGERMAN, E. 2001. Some aspects of wood structure and function. Journal of the Catgut Acoustical Society 4: 5–9.
BUCUR, V. 2006. Acoustics of wood, 2nd ed. Springer Series in Wood Science, Springer, Berlin, Heidelberg, Germany.
ZIERL, B. 2005. Obtaining the perfect violin sound - with fungi. Website https://www.empa.ch/web/s604/01-pilzholz [Accessed 06 May 2016].
Max Delbrück Center for Molecular Medicine. "Treatment with fungi makes a modern violin sound like a Stradivarius." ScienceDaily. ScienceDaily, 8 September 2012. <www.sciencedaily.com/releases/2012/09/120908081611.htm>.
I know a newly finished piece may take a few days to find its voice. I believe it has to do with the piece relaxing. That is, the wood has been forced to conform to a specific shape. If you take a piece of wood, cold bend it in a curve, then let the piece cycle through several dry/humid and hot/cold cycles it will for the most part hold its shape. The wood has a memory but will relax in the new shape after several cycles. The instrument will vibrate "better" once relaxed. Remember the wood is going from living wet to balanced dry in its environment. This process takes years. You can force it by placing it in a hot/dry kiln and temper the lignin in the wood. It speeds the process but in turn changes the way the wood reacts to its environment.
So to answer the question, yes and no. If a piece is made from air dried wood, it will certainly get better with age, kiln dried, not so much. IMHO
DAN
I think that, if you have sufficiently sophisticated and sensitive instrumentation (or perfect pitch and memory) that you might be able to detect a change in tone of an instrument over time-in-use. Urban myth has people placing instrument in from of large/loud speakers to absorb vibrations and theoretically "improve with age" an instrument placed in front of the blaring speakers.
I'd like to see some quantitative (measureable/recordable) evidence of such a shift in tone, but all we ever get is qualitative ('I notice', 'I can') evidence. It sounds so logical -- the wood would get more flexible on a cellular level after being continuously vibrated for X amount of time. But to the best of my knowledge, no one has ever conclusively proven the idea one way or another.
If someone had some serious sound measuring equipment, a spare dulcimer, an automatic strummer, a sound generator, and a year of time, I believe this urban myth could be confirmed or denied. Sadly, like so many other dulcimer myths, hardly anyone has the inclination to do any such testing. A couple years back I provided test recordings for those who claimed they could hear the difference between an hourglass shape and a teardrop shape, and only one person responded to my challenge. And the result didn't come anywhere close to proving he could hear the difference ('way less than 25% correct).
Sam, IMHO what I believe you are hearing are the natural differences in the thousands of factors which go into the construction of a dulcimer. The difference in tone between fingers/noter and fingers/pick is easily understood when you consider that flesh, compared to wood or plastic, absorbs and mutes vibrations from the strings.
Hi Marg,
In my experience, which is somewhat limited, a dulcimer's 'voice' DOES seem to change. I'm speaking from a new build standpoint, but I think it would apply to a newly purchased, new manufacture dulcimer as well. It may not always be fuller, but I do seem to detect a change in almost every one I build. Some do sound fuller. There is also the factor of your ear developing a tolerance for the new sound.
All that being said, I think several factors change the sound of our dulcimers. New strings, different gauge strings, a different key or even something as subtle as a change in humidity could make a difference.
I also seem to notice a difference when I play with fingers or a noter.
A good question and I'm sure there will be some fascinating discussion on it.
Sam
I have read several times, a dulcimer will have a fuller tone when broken in. Is this true? What causes this? Does this apply to only new dulcimers or could it also apply to older ones that were not played, put away for years than passed on to someone who is now playing it? Is it the dulcimer itself or the strings? Most will say new strings sound best, so how can a new dulcimer sound better later?
Sorry about so many questions but thinking of a fuller tone when broken in has let to many.
Replies most welcome on your thoughts.
