This article examines the influence of urbanization and industrialization on musical expression, with a focus on the role of urban noise as a creative element. The processes of urbanization and industrialization are frequently linked with an increase in noise levels, which is commonly regarded as a form of noise pollution. Nevertheless, this article underscores the potential for such noise to be transformed into a valuable aesthetic element within musical compositions. The research employs electro-acoustic theory and innovative techniques to transform noise into a novel musical element. The methods utilized include sound exploration and experimentation, evaluation, and composition employing both conventional and unconventional instruments. The techniques of sound manipulation are also employed in order to transform noise into an engaging musical experience. The outcome of this research is the musical work POSUA, which illustrates how urban noise can be transformed into a contemplative and creative musical experience, encouraging listeners to perceive noise from an original and innovative perspective. This article introduces a novel perspective on the potential of noise as a musical material and its role in fostering diversity within the contemporary music landscape.

Dynamic electrophoresis is the foundation for electroacoustical measurements, in which the electroacoustical signals may be used to analyze the size and electrostatic charge of colloidal entities by means of the results for dynamic electrophoretic mobility. Thus, the electrophoresis under an alternating electric field is the key foundation for electroacoustic theory. In this article, we develop a tractable analytical theory for the dynamic electrophoresis of hydrophobic and dielectric fluid droplets possessing uniform surface charge density. The tiny fluid droplets possess charged mobile surfaces and have found widespread applications in our day-to-day life. For dielectric fluid droplets (e.g., oil-water emulsions), the tangential electric stress at the interface is nonzero, which significantly affects its electrohydrodynamics under an oscillatory electric field, which has, however, a negligible impact on the electrophoretic motion of conducting droplets (e.g., mercury droplets). Besides, the micro/nanoscale fluid droplets often show hydrophobicity when they are immersed in an aqueous medium, and the impact of the electric field on hydrophobic surfaces remains a research frontier in the chemical discipline. Whereas a number of approximate expressions for electrophoretic mobility have been derived for the conducting droplet, none of them are applicable to such generic hydrophobic fluid droplets with dielectric permittivity that is significantly lower than or comparable to that of an aqueous medium. In this work, within the Debye-Hückel electrostatic framework, we elaborate an original analytical expression of dynamic electrophoretic mobility for this generic dielectric fluid droplet with a hydrophobic surface considering that the droplet retains its spherical shape during its oscillatory motion. We further derived a set of simplified expressions for dynamic electrophoretic mobility deduced under several limiting cases. The results are further illustrated, indicating the impact of pertinent parameters.

Concentrated suspensions were prepared from submicron cerium oxide particles, and particle size distribution (PSD) and zeta potential of the particles were researched by ultrasonic attenuation technology and electroacoustic theory. The influences of particle concentration, base solution and pH value on particle dispersion behavior in suspensions were analyzed. It was found that for suspensions with concentration from 10 wt% to 30 wt%, the ceria particles were dispersed most sufficiently in the suspensions with sodium hexametaphosphate (SHP), while for suspensions with concentration 40 wt%, the particles were dispersed most sufficiently in the suspensions with deionized water (DIW) only. On the other hand, the particles agglomerated most remarkably in all suspensions with sodium carboxymethyl cellulose (CMC), and they had the lowest value of zeta potential. It was deduced that higher zeta potential could be helpful for particle dispersion in these concentrated suspensions, while non-DLVO interaction and dispersing process might play important roles too.

The design of low-frequency sound absorbers with broadband absorption characteristics and optimized dimensions is a pressing research problem in engineering acoustics. In this work, a deep neural network based inverse prediction mechanism is proposed to geometrically design a Helmholtz resonator (HR) based acoustic absorber for low-frequency absorption. Analytically obtained frequency response from electro-acoustic theory is deployed to create the large dataset required for training and testing the deep neural network. The trained convolutional neural network inversely speculates optimum design parameters corresponding to the desired absorption characteristics with high fidelity. To validate, the inverse design procedure is initially implemented on a standard HR based sound absorber model with high accuracy. Thereafter, the inverse design strategy is extended to forecast the optimum geometric parameters of an absorber with complex features, which is realized using HRs and a micro-perforated panel. Subsequently, a quasi-perfect low-frequency acoustic absorber having minimum thickness and broadband characteristics is deduced. Importantly, it is demonstrated that the proposed absorber, comprising four parallel HRs and a microperforated panel, absorbed more than 90% sound in the frequency band of 347–630 Hz. The introduced design process reveals a wide variety of applications in engineering acoustics as it is suitable for tailoring any sound absorber model with desirable features.

Microperforated panel absorber was widely used in the fields of noise reduction and sound absorption, because it had the extraordinary advantages. As deformation of the standard microperforated panel, inclined microperforated panel absorber was proposed and investigated in this research. The theoretical sound absorption model of the inclined microperforated panel absorber was constructed on the basement of the Maa’s theory according to the electro-acoustic theory. Structural parameters of the inclined microperforated panel absorber were optimized on the basement of the constructed theoretical sound absorption model through the cuckoo search algorithm. The finite element simulation model of the inclined microperforated panel absorber with optimal parameters was built in the virtual acoustic laboratory, which could be considered as an effective method to measure and check the sound absorption performance of the inclined microperforated panel absorber. Through the theoretical modeling, parameter optimization, and finite element simulation, sound absorption performance of the inclined microperforated panel absorber was improved, which could be propitious to promote its practical applications in the fields of noise reduction and sound absorption.

This article examines the early reception of Pierre Schaeffer’s theoretical work in Quebec through the teaching of Marcelle Deschênes, principal author of the first electroacoustic theory and ear training curricula at both Université Laval and Université de Montréal. An account of Deschênes’s educational career is provided, along with remarks on the contents of her early courses in Morpho-typology and her listening workshops for children, using newly excavated primary material from her private archives. While existing scholarship presumes that Schaefferian thinking arrived in Quebec with the ‘orthodox’ acousmatic approach of Francis Dhomont, this article asserts that a pluralist and multidisciplinary interpretation of Schaeffer’s work can be discerned which pre-dated Dhomont’s teaching and has had an equally lasting impact overall. A methodological argument is also made for including education and other forms of ‘reproductive labour’ in the history of electroacoustic music.

This article argues for the habilitation of a concept of style in electroacoustic music. It surveys the reasons for the neglect of style, looking in particular at the modernist embedding of electroacoustic theory and the consequences of postmodern genre formations. It considers the extent to which academic understanding of the materiality of music has moved from the analysis of sound to the analysis of media. It offers a critique of notions of sonic inclusivity and the differentiation of electroacoustic music from instrumental music. It emphasises the importance of comparative analysis and understanding the elements of style in electroacoustic music. It critically examines a number of techniques and frameworks for stylistic analysis. It concludes by encouraging the electroacoustic music community to engage more fully with notions of style.

Sonification and electroacoustic music have different goals but share similar sound design and processing techniques. However, a fruitful crosspollination between these two domains is far from being a common and consolidated practice. On the contrary, the impression is that the two fields tend to underline their peculiarities as a matter of distinction one from the other: in simple terms, one is science, the other is art. In this work, we discuss our point of view about the actual and potential relationships between electroacoustic music and sonification from an interdisciplinary perspective. Sonification is considered here as a design discipline, ranging from the research in Auditory Display (AD) of the past decades to the more recent studies in Sonic Interaction Design (SID) (Franinovic and Serafin, 2013). On the one hand, we consider the manifold contribution that electroacoustic music theory and practice can give to sonification. On the other hand, we argue that Interaction Design (ID) in general, bei...

Ultrasound imparted air-recoil resonance (UIAR), a new method for acoustic power estimation, is introduced with emphasis on therapeutic high-intensity focused ultrasound (HIFU) monitoring applications. Advantages of this approach over existing practices include fast response; electrical and magnetic inertness, and hence MRI compatibility; portability; high damage threshold and immunity to vibration and interference; low cost; etc. The angle of incidence should be fixed for accurate measurement. However, the transducer-detector pair can be aligned in any direction with respect to the force of gravity. In this sense, the operation of the device is orientation independent. The acoustic response of a pneumatically coupled pair of Helmholtz resonators, with one of them acting as the sensor head, is used for the estimation of acoustic power. The principle is valid in the case of pulsed/ burst as well as continuous ultrasound exposure, the former being more sensitive and accurate. An electro-acoustic theory has been developed for describing the dynamics of pressure flow and resonance in the system considering various thermo- viscous loss mechanisms. Experimental observations are found to be in agreement with theoretical results. Assuming the window damage threshold (~10 J·mm(-2)) and accuracy of RF power estimation are the upper and lower scale-limiting factors, the performance of the device was examined for an RF power range of 5 mW to 100 W with a HIFU transducer operating at 1.70 MHz, and an average nonlinearity of ~1.5% was observed. The device is also sensitive to sub-milliwatt powers. The frequency response was analyzed at 0.85, 1.70, 2.55, and 3.40 MHz and the results are presented with respective theoretical estimates. Typical response time is in the millisecond regime. Output drift is about 3% for resonant and 5% for nonresonant modes. The principle has been optimized to demonstrate a general-purpose acoustic power meter.

Studying homogeneity and zeta potential of membranes using electroacoustics

Electroacoustic measurements of mixed quartz and iron oxide mineral systems

A distributed-feedback fiber laser hydrophone with band-pass response is presented. The design of the hydrophone aims to equalize static pressure and eliminate signal aliasing of high-frequency acoustic components. Theoretical analysis is presented based on electro-acoustic theory. The experimental results agree well with the theory. The measured underwater responses show that the hydrophone has a pressure sensitivity of -170 dB re:pm/μPa over a bandwidth between 100 Hz and 500 Hz. A sensitivity reduction exceeding -35 dB is observed at 2500 Hz. The tested static pressure sensitivity of the hydrophone is -226 dB. The proposed fiber laser hydrophone of this kind is expected to have important application in deep water fiber-optic sonar systems with anti-aliasing, and the understanding gained through this work can be extended to a guide of hydrophone design for required filtering bandwidth.

In this paper, a pressure-gradient fiber laser hydrophone is demonstrated. Two brass diaphragms are installed at the end of a metal cylinder as sensing elements. A distributed feedback fiber laser, fixed at the center of the two diaphragms, is elongated or shortened due to the acoustic wave. There are two orifices at the middle of the cylinder. So this structure can work as a pressure-gradient microphone in the acoustic field. Furthermore, the hydrostatic pressure is self-compensated and an ultra-thin dimension is achieved. Theoretical analysis is given based on the electro-acoustic theory. Field trials are carried out to test the performance of the hydrophone. A sensitivity of 100 nm MPa−1 has been achieved. Due to the small dimensions, no directivity is found in the test.

The seismoelectric effect: A nonisochoric streaming current: 2. Theory and its experimental verification

A general electroacoustic theory is presented for the macroscopic electric field in a dilute suspension of spherical colloidal particles in an electrolyte solution, which consists of the colloid vibration potential (CVP) and the ion vibration potential (IVP), induced by an oscillating pressure gradient field due to an applied sound wave. This is a unified theory that unites previous theories for CVP and those for IVP. Approximate analytic expressions are derived for CVP and IVP. The obtained IVP expression agrees with Debye's formula that is corrected by taking into account the force acting on the electrolyte ions as a result of the pressure gradient in the sound wave. The obtained CVP expression is correct to the first order of the particle zeta potential and applicable for arbitrary kappaalpha, where kappa is the Debye-Hückel parameter and alpha is the particle radius. It is found that an Onsager relation holds between CVP and dynamic electrophoretic mobility. It is also shown that the CVP from particles with very small kappaalpha approaches IVP; that is, in the limit of very small kappaalpha a particle behaves like an ion.

Electroacoustic theory for concentrated colloids with overlapped DLs at arbitrary kappa alpha. I. Application to nanocolloids and nonaqueous colloids.

Abstract Recently, significant advances have been made in the theory and application of acoustic and electroacoustic spectroscopies for measuring the particle-size distribution (PSD) and zeta potential (ζ potential) of colloidal suspensions, respectively. These techniques extend or replace other techniques, such as light-scattering methods, particularly in concentrated suspensions. In this review, we summarize acoustic and electroacoustic theory and published results on clay mineral suspensions, detail theoretical constraints, and indicate potential applications for the study of environmentally significant clay mineral suspensions. Using commercially available instrumentation and suspension concentrations up to 45 vol.%, acoustic spectroscopy can characterize particle sizes from 10 nm to 10 µm, or greater. Electroacoustic spectroscopy can determine the ζ potential of a suspension with a precision and accuracy in the mV range. Despite the clear potential for their use in environmental settings, to date, acoustic methods have been used mainly on clay mineral colloids with industrial application, typically combined with similar measurements such as isoelectric point (IEP) determined from shear yield stress or ζ potential from electrophoretic mobility measurements. Potential applications in environmentally relevant suspension concentrations are significant, as PSD and ζ potential are important factors influencing the transport of mineral colloids and associated contaminants through porous media. Applications include determining the effects of suspension concentration, surfactants, electrolyte strength, pH and solution composition on soil clay properties and colloidal interactions, and determining changes in PSD, aggregation and ζ potential due to adsorption or variations in the clay mineralogy.

New developments in acoustic and electroacoustic spectroscopy for characterizing concentrated dispersions

In our previous paper,1 we have derived a new electroacoustic theory for concentrated (up to 45 vol%) polydisperse colloids. We assumed two simplifications: thin double layer and negligible surface conductivity. In this paper, we generalize this theory eliminating the second assumption by taking into account the surface conductivity influence on the electroacoustic CVI signal.

There are two quite different approaches to deriving an electroacoustic theory. The first was suggested by Enderby and Booth 50 years ago and later modified by Marlow, Fairhurst and Pendse. The second was suggested by O'Brien about 10 years ago (O'Brien's approach). He introduced a special relationship between kinetic coefficients that is assumed to be valid in a concentrated system. This approach requires also a theory for dynamic electrophoretic mobility. The most recent version of this theory for concentrated systems was created by Ohshima, Shilov, and A. Dukhin on the basis of the cell model. A hybrid of the O'Brien relationship and this new electrophoretic mobility theory yields expressions for electroacoustic effects in the concentrated systems. We call it “hybrid O'Brien's theory”. In principle these two approaches must lead to the same result. To test this expectation, we should generalize the first approach such that it is valid for concentrates. We have done this using the Kuvabara cell model fo...