Musical Acoustics

Jim Cottingham

Students working in Prof. Jim Cottingham's group carry out studies on the acoustics of musical instruments, with a strong emphasis on wind instruments using so-called free reeds. The free reed instruments include the harmonica, the accordion-concertina family, and the reed organ. A major portion of the acoustics research at Coe has been on the acoustics of the Asian free reed mouth organs, in which a free reed is coupled to a pipe resonator. These Asian instruments include the khaen (Thailand/ Laos), the sheng (China), and the bawu (China). Other recent areas of research at Coe have included the interaction of an air jet with a resonator (relevant to flute- like instruments), acoustics of tuned drum heads, and the acoustics of choirs and vocal ensembles.

Musical acoustics research makes extensive use of Fast Fourier Transform (FFT) spectrum analysis and the modal analysis of vibrating systems. Studies of reed motion and modes of vibration may employ a variety of instruments including variable-impedance-transducer (VIT) proximity sensors, a laser vibrometer system, and high speed photography. Acoustics research at Coe has also involved in measurement of acoustic input impedance curves of the pipes or other resonators and theoretical modeling of the motion of the air-driven reed and reed-resonator coupling. Recent areas of study include the investigation of the spectra of attack transients and measurement and visualization of sound fields within resonators. In addition to experimental measurements, recent work has included using COMSOL Multiphysics® to construct simulations. Work on these simulations will be continuing this summer.

Bio and Interests

I have been working with undergraduate students in musical acoustics research since 1990. During this period more than 70 students have been involved. Many have presented papers at national or international acoustics meetings including meetings in Cancun, Honolulu, Berlin, Vienna, and Hong Kong. Several of the acoustics research students have gone on to graduate study in acoustics. Email: jcotting@coe.edu