Sound simulation-based design optimization of brass wind instruments.

A method for optimizing the inner shape of brass instruments using sound simulations is presented. This study considers different objective functions and constraints (representative of both the intonation and the spectrum of the instrument) for a relatively large number of design variables. A complete physics-based model, taking into account the instrument and the musician's embouchure, is used to simulate steady regimes of sounds by means of the harmonic balance technique, the instrument being represented by its input impedance.

Measurements and time-domain simulations of multiphonics in the trombone.

Multiphonic sounds of brass instruments are studied in this article. They are produced by playing a note on a brass instrument while simultaneously singing another note in the mouthpiece. This results in a peculiar sound, heard as a chord or a cluster of more than two notes in most cases.

Effects of nonlinear sound propagation on the characteristic timbres of brass instruments.

The capacity of a brass instrument to generate sounds with strong high-frequency components is dependent on the extent to which its bore profile supports nonlinear sound propagation. At high dynamic levels some instruments are readily sounded in a "cuivré" (brassy) manner: this phenomenon is due to the nonlinear propagation of sound in ducts of the proportions typical of labrosones (lip-reed aerophones). The effect is also evident at lower dynamic levels and contributes to the overall tonal character of the various kinds of brass instrument.

Motion of the lips of brass players during extremely loud playing.

When a brass instrument is played loudly, the energy level of the higher harmonics increases dramatically. The generally accepted explanation for this is non-linear steepening of the wavefront and generation of shock waves within the instrument bore. However, it has also been suggested that changes in the player's lip vibration could play a role in generating this "brassy" sound.

Interaction of reed and acoustic resonator in clarinetlike systems.

Sound emergence in clarinetlike instruments is investigated in terms of instability of the static regime. Various models of reed-bore coupling are considered, from the pioneering work of Wilson and Beavers ["Operating modes of the clarinet," J. Acoust.

Influence of wall vibrations on the behavior of a simplified wind instrument.

The issue of the influence of wall vibrations on the behavior of wind instruments is still under debate. The mechanisms of vibroacoustic couplings involved in these vibrations are difficult to investigate, as fluid-structure interactions are weak. Among these vibroacoustic interactions, the present study is focused on the coupling between the internal acoustic field and the mechanical behavior of the duct.

A simulation tool for brassiness studies.

A frequency-domain numerical model of brass instrument sound production is proposed as a tool to predict their brassiness, defined as the rate of spectral enrichment with increasing dynamic level. It is based on generalized Burger's equations dedicated to weakly nonlinear wave propagation in nonuniform ducts, and is an extension of previous work by Menguy and Gilbert [Acta Acustica 86, 798-810 (2000)], initially limited to short cylindrical tubes. The relevance of the present tool is evaluated by carrying out simulations over distances longer than typical shock formation distances, and by doing preliminary simulations of periodic regimes in a typical brass trombone bore geometry.

Mechanical response measurements of real and artificial brass players lips.

Mechanical frequency responses of human and artificial lips in brass instrument playing have been measured using a high-speed digital video technique, in an attempt to classify the true nature of the "lip-reed." Four semiprofessional human players were used, and three notes played on a trombone were studied. All measurements revealed a strong mechanical resonance with "outward striking" behavior; the played note always sounded above this frequency.

An analytical prediction of the oscillation and extinction thresholds of a clarinet.

This paper investigates the dynamic range of the clarinet from the oscillation threshold to the extinction at high pressure level. The use of an elementary model for the reed-mouthpiece valve effect combined with a simplified model of the pipe assuming frequency independent losses (Raman's model) allows an analytical calculation of the oscillations and their stability analysis. The different thresholds are shown to depend on parameters related to embouchure parameters and to the absorption coefficient in the pipe.

Study of the brightness of trumpet tones.

This study focuses on a particular attribute of trumpet tones, the brightness, and on the physical characteristics of the instrument thought to govern its magnitude. On the one hand, an objective study was carried out with input impedance measurements, and, on the other hand, a subjective study with hearing tests and a panel of subjects. To create a set of different trumpets a variable depth mouthpiece was developed whose depth can be easily and continuously adjusted from "deep" to "shallow.

Nonlinear characteristics of single-reed instruments: quasistatic volume flow and reed opening measurements.

A wind instrument can be described as a closed feedback loop made up of a linear passive element-the resonator-and a lumped nonlinear element-the mouthpiece. A method for measuring the nonlinear characteristics of the mouthpiece-nonlinear flow relationship-in static condition is given. An artificial mouth is used in which the volume flow is deduced from the pressure difference between both sides of a constriction (orifice) which takes place in the resonator.