"Our research shows that freezing trumpets does not make a better sounding instrument," said Professor Chris Rogers at Tufts University's School of Engineering. "One of the great things about studying musical instruments, though, is if the player believes it will make a difference, he or she will play better, so it acts as a sort of placebo."
Rogers conducted the research for two years with his former graduate student Jesse Jones IV, who will present the team's findings on Nov. 11 at the 146th meeting of the Acoustical Society of America (ASA) in Austin, Texas. The ASA is the largest scientific organization in the United States devoted to acoustics, with more 7,000 members worldwide.
The Tufts researchers analyzed 10 trumpets -- five of which were cryogenically treated -- and found there is no statistically significant difference between treated and untreated instruments. In fact, differences from player to player, and instrument to instrument, overshadowed any changes that cryogenic treatment might have produced.
Rogers and Jones cooled the instruments to -195 degrees Celsius (-321 degrees Fahrenheit) and then let them slowly return to room temperature. The process is a dry one as the trumpet is placed in a chamber cooled by liquid nitrogen, but the nitrogen never contacts the trumpet.
"We set out to see if the growing practice actually has any impact on the sound of the instrument - and found that it didn't," said Rogers. "Even though elite players from around the world have adopted this practice, it is unclear how or why cooling one's trumpet would affect the sound of the instrument."
A faction in the trumpet-playing culture believes a cryogenically treated trumpet has a better tone -- often referred to as timbre by musicians -- and a more distinct presence, a common term that musicians use to describe the "special sparkle" of a sound that one instrument has over other instruments.
Proponents of this practice believe that cryogenically treated trumpets play in tune more easily as their notes are more centered. They also believe that the treated instruments won't tire the trumpeters as much. (Trumpets are one of the most physically demanding instruments to play.)
"Some musicians will say this allows them to play their trumpet all night long," said Jones.
Firms that offer cryogenic processing say the treatment results in a trumpet that is artificially aged and that any internal stresses due to manufacturing are relieved.
"Heating softens metal and relieves stresses, so it is difficult to understand how freezing a trumpet would also relieve stress," said Jones.
In 1998, Selmer Musical Instruments, maker of many orchestra wind instruments including the Vincent Bach Stradivarius trumpet, became interested in offering the cryogenic treatment as a factory option to its customers. Before moving forward, the company asked the Tufts engineers to independently verify the beliefs about cryogenically treating trumpets.
The Tufts team approached the research from three perspectives: materials science, quantitative acoustic measurements and qualitative player responses. The sample set was comprised of 10 Bach Stradivarius trumpets randomly picked from the Selmer production line, half of which were cryogenically treated. The engineers then enlisted six players with proficiencies ranging from beginner to professional to help test the trumpets.
The materials science phase of the study found no changes in the crystalline structure of the brass on the microscopic level. The researchers attempted to identify differences in timbre by measuring frequency content of a sound and graphically displaying what frequencies are present to get a quantitative description of the sound.
"As far as we can tell, the differences from trumpet to trumpet, player to player, and session to session far overshadow any difference brought on by cryogenic treatment," said Jones.
The trumpet research is part of Tufts' Musical Instrument Engineering program launched by Rogers and Jones in 1998. An interdisciplinary partnership of the University's music, mechanical engineering, and electrical engineering departments, the program is one of just a handful of its kind in the country.
Rogers was recently named by the National Science Foundation (NSF) as one of six 2003 Distinguished Teaching Scholars nationwide, the NSF's highest honor for excellence in teaching and research. He was recognized for his work in making engineering accessible and exciting to students of all ages and fields of study. For more information about Rogers' research, please see www.tuftl.tufts.edu.
Note to editors: Here is a link to the paper Jones is presenting at the National Acoustical Society of America: http://www.
Tufts University, located on three Massachusetts campuses in Boston, Medford/Somerville, and Grafton, and in Talloires, France, is recognized among the premier research universities in the United States. Tufts enjoys a global reputation for academic excellence and for the preparation of students as leaders in a wide range of professions. A growing number of innovative teaching and research initiatives span all Tufts campuses, and collaboration among the faculty and students in the undergraduate, graduate and professional programs across the University's eight schools is widely encouraged.