One of the characteristic features of the sound of a brass instrument is the way in which the timbre becomes brighter during a crescendo. The spectrum of a quiet note on any brass instrument is dominated by the lowest three or four harmonic components; as the loudness is increased upper harmonics become relatively more significant. In instruments with a large proportion of cylindrical tubing the spectral enrichment is particularly dramatic, leading to the “brassy” timbre of a fortissimo note on a trombone. An important contributing factor in the generation of very high frequency spectral components is nonlinear sound propagation in the bore of the instrument. This paper presents the results of recent experimental studies of the propagation of high amplitude wave packets in cylindrical tubes with dimensions similar to those in trumpets and trombones, and discusses the significance of the results for predictions of the rate of spectral enrichment based on measurements of the bore profile of such instruments.
|Title of host publication||International Symposium on Musical and Room Acoustics (ISMRA) Proceedings|
|Place of Publication||La Plata, Buenos Aires, Argentina|
|ISBN (Print)||978-987-24713-8-5 |
|Publication status||Published - 30 Sep 2016|