Open and Muted Brasses. What happens inside the instrument? Alippi, Adriano (Hg). in: Proceedings of ICA '2001 (17th International Congress on Acoustics in Rome). CD [ISBN 88-88387-03-X], 2001. Vol IV - Section Music - Session Wind Instruments.

The title question has caused an unending discussion between horn players and acousticians during the last 50 years. The phenomenon is well known: if one puts his hand into the bell, the blown note gets more and more flat to a certain point, where it then skips a semitone upwards. Musicians are convinced, for example, that hand stopping shifts all notes a semitone upwards. Mostly, acousticians successfully disprove the opinion of the players, but contradicting hypotheses they present about phenomena happening inside the instrument fail to convince players. After a discussion of various theories, this paper tries to shed light on this question, and describes experiments done with hand-stopped and muted horns. Input impedance measurements where used to get basic information, and in a second step, physical modeling techniques were used to determine the position of pressure nodes and antinodes inside the tube. (Widholm G., Anglmayer P., Kausel W.)

Silver, gold, platinum - and the sound of the flute. Stanzial, Domenico (Hg). in: Proceedings of ISMA '2001 (International Symposium on Musical Acoustics). Nr. Vol.2. Perugia: Musical and Architectural Acoustics Lab. FSSG-CNR Venezia, 2001. S.277-280. (Widholm, Gregor; Bertsch, Matthias; Kausel, Wilfried; Linortner, Renate)

The discussion on the influence of the material of wind instruments on the sound color is unending. While acousticians speak mostly of a negligible influence, players are convinced that the material highly influences the color of the radiated sound. This paper reports on experiments done with 7 different flute materials and 110 testpersons, where the price of the instruments is between € 3,000.- and € 73,000.- (!). Double blind tests and statistical analysis showed players‘ and listeners´stereotyped ideas on that matter and the non-recognizability of the used material. Sound analysis pointed out big differences in the sound level and sound color of played tones caused by the player and just measurable but not perceivable differences (< 0,5 dB) in sound color caused by the material.