Phenomenon Stopped Horns

Diploma Thesis (pdf. 5.426KB)

Muting techniques have been used for about 250 years to modify a horn’s sound and intonation. The more the right hand is being fed into the bell the more the pitch drops. At a certain point, however, when the hand closes approximately 95 percent of the bell opening, the pitch produced is one semitone sharper than it would be for the open instrument. Acousticians still heavily discuss whether the pitch in fact gets higher or lower. In this thesis the open and stopped horn is acoustically analysed by means of in-put impedance and transfer function measurements. In addition, nodes and antinodes of the instrument are depicted by the simulation software "Optimiser". By comprehensive studies acoustic processes shall be revealed with regard to the stopped horn.