Texas A&M biochemistry professor Joseph Nagyvary, recently published a study in Savart Journal discussing some of the violin's human-sounding qualities. According to the study, the instrument is capable of producing vowel sounds like the Italian "i" and "e" along with other vowels borrowed from English and French.
Nagyvary had previously studied violin makers Stradivari and Guarneri to find out what made their instruments sound particularly human. He found that they had stored their violins in chemicals to protect the wood from an infestation of worms that pervaded Italy in the 16th century. Somehow, the brine and borax they used produced a sound difficult to reproduce in modern day violins — that of a female soprano.
So Nagyvary recorded an opera singer belting out a string of vowels and compared her to a 1980s recording of Itzhak Perlman playing a scale on a Guarneri violin from 1743. Here's Nagyvary on his experiment:
"I analyzed her sound samples by computer for harmonic content and then using state-of-the art phonetic analysis to obtain a 2-D map of the female soprano vowels. Each note of a musical scale on the violin underwent the same analysis, and the results were plotted and mapped against the soprano vowels."
Both the opera singer and the Guarneri violin could be mapped on the same scale, meaning that these classic violin makers were trying to imitate the human voice. They must have been on to something because Guarneri violins have sold for as much as $20 million. Now that sound quality can be tested against the great violin masters from Italy, will this sort of mapping become the norm for quality testing?