"...These differences in density differentials may reflect similar changes in stiffness distributions, which could directly impact vibrational efficacy or indirectly modify sound radiation via altered damping characteristics. Either of these mechanisms may help explain the acoustical differences between the..." You may be surprised to hear what this discussion is all about. If you're a high-end audio skeptic this may make you think differently.
Imagine the previous statement coming from some of the top high-end speaker manufacturers like Vandersteen, Wilson Audio, Magico, B&W etc... The Internet forums would blow up with skeptics deploring this "marketing" tactic as yet another high-end fallacy. This statement however is all about classical violins created by Cremonese masters, such as Antonio Stradivari and Giuseppe Guarneri Del Gesu. Recent research into why the old violins sound so good has unearthed some things that high-end audio manufacturers have probably known for decades. If you have some time over this long holiday weekend here in the U.S. I highly recommend reading this paper. It has some very real parallels with high-end audio.
Link to paper A Comparison of Wood Density between Classical Cremonese and Modern Violins