Joël Gilbert

Université du Maine · Acoustical Laboratory of the Université du Maine (LAUM)

An optimization method is proposed to find mask parameters of a brass player coming from a one degree of freedom lip model, with only constant mouth pressure and periodic mouthpiece pressure as input data, and a cost function relying on the waveform and the frequency of the signal. It delivers a set of parameters called 𝒞 C$ \mathcal{C}$-admissibl...

The ghost note is a natural note which can be played exclusively on bass brass instruments with a predominantly-expanding bore profile such as tubas, euphoniums or saxhorns. It stands between the pedal note – the lowest natural note playable, or first regime – and the instrument’s second regime. However, if the interval between the pedal note and t...

The ghost note is a natural note which can be played exclusively on bass brass instruments with a predominantly-expanding bore profile such as tubas, euphoniums or saxhorns. It stands between the pedal note-the lowest natural note playable, or first regime-and the instrument's second regime. However, if the interval between the pedal note and the s...

In this study, an acoustic resonator -- a bass brass instrument -- with multiple resonances coupled to an exciter -- the player's lips -- with one resonance is modelled by a multidimensional dynamical system, and studied using a continuation and bifurcation software. Bifurcation diagrams are explored with respect to the blowing pressure, in particu...

In Oil & Gas industry, the high internal sound pressure levels in pipe lines often cause significant structural vibrations. Quantification of the internal acoustic pressures is therefore an important step in understanding the global fluid–structure behaviour of such systems. However, direct acoustic measurements are often not possible since they ge...

This book provides an in-depth account of the fascinating but far from simple actions and processes that take place when a brass instrument is played. Written by three leading researchers in brass instrument acoustics who are also experienced brass players, it draws together the many recent advances in our understanding of the subtly interrelated f...

This chapter gives a definition of ‘brass instruments’ (or ‘labrosones’) and briefly outlines their variety and development over several millennia. The musician’s interpretation of the brass playing experience is described in terms of the pitches of the readily playable notes, slotting, compass, intonation control (note bending), dynamic range, tim...

This chapter offers an overview of the materials, equipment and techniques used to make brass instruments. It discusses the processes of design and manufacture through which instrument makers exercise control in order to meet the requirements of musicians. Hand craft techniques and operations which can be mechanised are outlined. Designs of valve s...

In this chapter we discuss the factors which distinguish the commonly recognised species of brass instrument. It is asserted that bore profile is the principal determinant of the character of an instrument. Parameters which can be derived from physical measurement of instruments (or from instrument makers’ designs) are identified. The main kinds of...

This chapter presents an elementary model, involving some approximations and simplifications, of a brass instrument under playing conditions. This model is capable of reproducing many features of performance by musicians including control of embouchure to select one of a number of natural notes, and to pull its pitch up or down by the subtle embouc...

This chapter explores refinements of the elementary model of a brass instrument under playing conditions. The theory of spectral enrichment resulting from nonlinear sound propagation is presented in order to explain the brassy character of brass instruments when played loudly. The extreme case of shock wave (N-wave) generation in the air column of...

This chapter discusses the application of the classic scientific method to observe, measure and record the behaviour of brass instruments and develops a simple theory (or “model”) to explain the main features of this behaviour. The sound pressure levels inside the player’s mouth and the instrument mouthpiece are related to the radiated sounds. The...

This chapter deals with the vibrating lips as a sound source: this is a defining feature of all labrosones (brass instruments). The main processes through which the air flow generated by the player’s lungs can initiate and sustain the vibration of the lips are covered. The facial muscles which control the embouchure of a brass player are described,...

In this chapter describes the resonant properties of the air column contained within a brass instrument and the nature of the sound radiated from it. The wave equation is presented. Lumped and distributed resonators are defined; travelling and standing waves are explained, and the relationship between standing waves and acoustic resonances is discu...

This chapter presents examples of studies in which scientific techniques have assisted the construction of playable reproductions of instruments from the ancient world, including the Etruscan cornu and the Celtic carnyx. The book concludes with a discussion of some recent developments which exploit digital technology including optimisation algorith...

In this study, an acoustic resonator – a bass brass instrument – with multiple resonances coupled to an exciter – the player’s lips – with one resonance is modelled by a multidimensional dynamical system, and studied using a continuation and bifurcation software. Bifurcation diagrams are explored with respect to the blowing pressure, in particular...

A reed instrument model with N acoustical modes can be described as a 2N dimensional autonomous nonlinear dynamical system. Here, a simplified model of a reed-like instrument having two quasi-harmonic resonances, represented by a four dimensional dynamical system, is studied using the continuation and bifurcation software AUTO. Bifurcation diagrams...

This work involves the theoretical and experimental study of the vibroacoustic coupling occurring in a bent pipe line in the plane wave domain. In this type of piping line, resulting forces located in the elbows are generated by the internal sound pressure. The objective is then to estimate the internal pressure field as a function of the accelerat...

This research work deals with the active control of the sound radiated by a brass instrument. The general goal is to reduce the radiated sound level without altering the input impedance of the instrument. This paper focuses only on the active control of the radiated power. The control is performed by several loudspeakers located outside close to th...

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 in...

In industrial energy production sites, the manufacturing processes induce the use of piping networks subject to strong environmental constraints (transport of dangerous gases at high pressure and high temperature). Reciprocating compressors connected to these networks behave like acoustic sources whose pulsations induce vibrations of structures by...

Males of several species of deer have a descended and mobile larynx, resulting in an unusually long vocal tract, which can be further extended by lowering the larynx during call production. Formant frequencies are lowered as the vocal tract is extended, as predicted when approximating the vocal tract as a uniform quarter wavelength resonator. Howev...

A.P.J. (Bram) Wijnands (1934-2017) was a skilled musician and music instrument builder. He was mostly involved with renaissance music with the group Au Joly Bois. Around 1984 Bram initiated a study on the geometry of the recorder mouthpiece, based on flow visualization. Inspired by the work of Philippe Bolton, he was seeking for the optimization of...

Dans le cadre du développement du projet PAFI, le pôle d’innovation de l’artisanat de l’ITEMM met à disposition des facteurs d’instruments des outils de modélisation d’impédance d’entrée à partir d’une perce associée. La prédiction des fréquences de jeu issues de ces modèles reste encore un vaste sujet de recherche. La présente étude se concentre s...

Wind instruments driven by a constant pressure air reservoir produce a steady oscillation and associated sound waves. This self-sustained oscillation can be explained in terms of a lumped element feedback loop composed of an exciter, such as a reed-valve or an unstable jet, coupled to an acoustical air column resonator, usually a pipe. In this chap...

Trumpet calls are very loud voiced signals given by highly aroused elephants, and appear to be produced by a forceful expulsion of air through the trunk. Beyond their characteristic “brassy quality” previously attributed to shockwave formation, some trumpet calls are also characterized by stepwise fundamental frequency increase and decrease. Here w...

Recent archaeological discoveries, most notably at the Gallo-Roman site at Tintignac in the Corrèze district of France, have thrown fresh light on the nature of some of the lip-excited wind instruments used in Europe around two thousand years ago. In particular, it has been possible to reconstruct working copies of the Celtic horn known as the carn...

A time-domain numerical model of brass instrument sound production is proposed as a tool to predict their brassiness. It is based on the generalized Burger's equations which can be used to model weakly nonlinear wave propagation in non uniform ducts, as described in [1] where a frequency domain tool has been presented. The relevance of the present...

A physical model of brass instrument is considered in this paper: a one degree-of-freedom outward-striking valve for the lips, non-linearly coupled to a modal representation of the air column. It is studied through Linear Stability Analysis (LSA) of the equilibrium solution. This approach provides the threshold blowing pressure value, at which inst...

Science and science education are a focus of high-level government policy settings in many countries. Greater public interest in and knowledge of science is seen as being an important prerequisite for economic growth and social development in the Knowledge Age. In this article, I argue that current policy approaches are misguided and potentially ha...

This paper presents a method for design optimization of brass wind instruments. The shape of a trumpet's bore is optimized to improve intonation using a physics-based sound simulation model. This physics-based model consists of an acoustic model of the resonator, a mechanical model of the excitator, and a model of the coupling between the excitator...

This paper investigates the subjects' ability to perceive trumpet sound changes, the sounds being either simulated by physical modeling or played by a real musician. The objective of the paper is to study to what extent simulations are able to create perceptually distinct sounds and to compare the discrimination on simulated sounds to the discrimin...

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. This effect is used in different artistic contexts. Measurem...

Males of several species of deer have a descended larynx, which gives them an unusually long vocal tract (VT). They can extend their VT by further lowering their larynx during the production of their sexual loudcalls. Formant frequencies are lowered as the vocal tract is extended, as predicted when approximating the vocal tract as a uniform quarter...

In the previous chapters, it was assumed that the amplitude of both air and structural oscillations in musical instruments were sufficiently small so that the assumption of linearity for their underlying models was fulfilled. However, this assumption is no longer valid in a number of situations encountered in musical acoustics, and a nonlinear appr...

With an average male body mass of 320 kg, the wapiti, Cervus canadensis, is the largest extant species of Old World deer (Cervinae). Despite this large body size, male wapiti produce whistle-like sexual calls called bugles characterised by an extremely high fundamental frequency. Investigations of the biometry and physiology of the male wapiti's re...

Cet article présente une nouvelle méthode d’optimisation de la géométrie d’un instrument de type cuivre (la trompette), en se basant sur des simulations sonores par modèle physique. Le modèle physique consiste en un modèle acoustique du résonateur (l’impédance d’entrée), un modèle mécanique de l’excitateur (les lèvres du musicien virtuel) et un mod...

Avant leur lancement dans l’espace, les satellites sont teste ́s et expose ́s, entre autres, a` des niveaux sonores comparables a` ceux existant pendant la phase de de ́collage du lanceur. Dans les syste`mes usuels, ces niveaux sonores sont obtenus a` l’aide de sources e ́lectropneumatiques. Elles modulent aux fre ́quences acoustiques l’e ́coulemen...

Narrow-bore instruments are commonly perceived to be brighter than wide-bore models of the same kind of instrument. This effect is closely related to the effect of the bore profile of a brass instrument on the potential for non-linear propagation of sound within the tube. This paper reports on practical tests with trumpets of different bore diamete...

The carnyx was a metal wind instrument used by Celtic peoples around two thousand years ago. It was approximately two meters long with a bell in the shape of an animal head. In 2004, an excavation at Tintignac in the Corrèze district of France uncovered a horde of bronze instruments, including parts of several carnyxes. It proved possible to assemb...

Though thermoacoustic engines usually operate at high acoustic amplitude, they rarely exhibit strong deformation of the wavefront due to nonlinear propagation. It has however been demonstrated experimentally that obtaining shock waves in thermoacoustic engines is possible under specific con-ditions. This paper aims at presenting a simple descriptio...

African elephants (Loxodonta africana) produce a broad diversity of sounds ranging from infrasonic rumbles to much higher frequency trumpets. Trumpet calls are very loud voiced signals given by highly aroused elephants, and appear to be produced by a forceful expulsion of air through the trunk. Some trumpet calls have a very distinctive quality tha...

This paper addresses the perception of differences between sounds of trumpets played by a musician or simulated by physical modeling. The harmonic balance technique is used to simulate trumpet sounds in permanent regime. The input parameter of the simulations is the input impedance of the trumpet (resonator), the control parameters are the characte...

Since the discovery nearly twenty years ago that nonlinear propagation of the internal sound wave in a trombone was primarily responsible for the "brassy" timbre in fortissimo playing, it has become increasingly clear that nonlinear distortion even at moderate sound levels can contribute significantly to the tonal character of a brass instrument. P...

The history of musical instruments shows that they have mainly been developed empirically. The engineers and the researchers in acoustics can nowadays propose many sophisticated tools to characterize and to model complex mechanical systems (by identifying modal characteristics of a vibrating structure or a column of air), to characterize materials...

The aim of this work is to study experimentally the relationship between the resonance frequencies of the trumpet, extracted from its input impedance, and the playing frequencies of notes, as played by musicians. Three different trumpets have been used for the experiment, obtained by changing only the leadpipe of the same instrument. After a measur...

Elephants produce a broad range of sounds from very low frequency rumbles to higher frequency trumpets. Trumpets are produced by a forceful expulsion of air through the trunk. Trumpets are mainly tonal sounds. Elephants tend to trumpet when they are highly stimulated and the quality of trumpeting varies with the context.Some elephant trumpeting sou...

Time domain responses of porous media have been studied by some authors, but generally the possible descriptions are given in the frequency domain. The aim of this paper, limited to materials with rigid skeleton considered as equivalent fluids, is to compare in time domain different descriptions by Johnson-Allard (JA) as well as by Pride-Lafarge (P...

This paper addresses the use of sound simulations for instrument characterization. It focuses on the ability of simulations by physical modelling to create sounds characteristic of a given instrument. The harmonic balance technique is used to generate trumpet sounds in permanent regime. The input parameters of the simulations are the input impedanc...

Lip-type valve is responsible for sound production for brass instruments. The operation of the valve is controlled by feedback from a passive resonator. The purpose of this study is to compare experimentally how far the resonance frequencies of instrument, taken from their input impedance (which does not involve the intervention of the player's lip...

Lip-type valve ("striking outwards" type) is responsible for sound production for brass instruments. The operation of the valve is controlled by feedback from a passive resonator. The purpose of this study is to compare experimentally how far the resonance frequencies of instrument, taken from their input impedance (which does not involve the inter...

The influence of wall vibrations on the sound produced by a wind instrument is an open question. If it is clear that the vibrations of bells vibrations can be felt and measured, the influence of these vibrations on the radiated sound is more difficult to bring to light, because the fluid-structure couplings involved are particularly weak except whe...

Friction-induced noises are numerous in the automotive field. They also involve a large number of structures. Wiper squeal, seat squeak or dashboard creak are some examples of these noises. The different names traditionally used to describe these noises allow a first classification, especially based on their acoustical signature. From an experiment...

Measurements and calculations of the input impedance of wind musical instruments are now well mastered. The purpose of this work is to study experimentally how far the resonance frequencies of brass instruments, taken from their input impedance, are able to give informations about the playing frequencies. Three different trumpets, obtained by chang...

Friction-induced noises are numerous in the automotive field. They also involve a large number of structures. Wiper squeal, seat squeak or dashboard creak are some examples of these noises. The different names traditionally used to describe these noises allow a first classification, especially based on their acoustical signature. From an experiment...

The modeling of wave propagation in a horn is still problematic as the limit of plane wave approximation is known but no method is proven to give accurate results. This paper proposes to evaluate the error induced by both a plane wave model and a spherical model. These models use a Transmission-Matrix Method based on either plane or quasi-spherical...

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...

A century ago, Science published a spectacular experimental study on the physics of organ pipes. Dayton C. Miller observed experimentally that the sound produced by an organ pipe can depend on the vibration of its walls, in addition to its internal geometry and the interaction between the air jet and the labium. The Miller experiment has been repea...

Transient waves can be used for the characterization of porous media. For materials with rigid skeleton and cylindrical pores, the response is known in the frequency domain since Zwikker and Kosten. The impulse response can be computed by FFT with some precautions. It is interesting to compare it with asymptotic formulas: The dimensionless paramete...

The quality of a musical instrument embraces many aspects such as tuning, ease of play, tone, etc. This study aims to validate the use of the sum function (SF) proposed by Wogram from the measurement of input impedance as a descriptor of quality. This work is part of a wider project, PAFI (Aid Platform for Instrumental Making), supported by the Fre...

Le grincement est un bruit induit par le frottement dont la nature fugace est tr es souvent mise en avant expérimentalement. Cet article présente l'´ etude menée sur un mod ele de principe, contenant deux masses en contact frottant et obtenu suitè a l'´ evolution du mod ele classique de stick-slip par une démarche de complexité croissante. Alors qu...

This work is part of a project aiming at helping craftsmen to design and characterize their musical instruments. Starting from a given wind instrument shape, our objective consists in choosing the most relevant physical model able to predict the acoustical input impedance of this musical instrument once constructed. The modeling of bells in bras...

At high acoustic level, non-linear losses at the end of a tube are usually interpreted as the consequence of a jet formation at the tube end resulting in annular vortices dissipating part of the acoustic energy. Previous work has shown that two different regimes may occur. The present work, using particle image velocimetry visualization, lattice Bo...

When a trombone is played at a high dynamic level, nonlinear sound propagation leads to a gradual distortion of the form of the acoustic pressure wave travelling from the mouthpiece towards the bell. This distortion is a significant factor in the spectral enrichment of the radiated sound which is a characteristic feature of a trombone played loudly...