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The article announces the resignation of the Executive Editor-in-Chief of the journal Matter & Radiation at Extremes (MRE) due to health reasons. The author expresses gratitude to the previous and current Editor-in-Chiefs, as well as the associate editor team, advisory editorial board members, and staff for their contributions to the success of MRE. The article also acknowledges the collaboration with AIP Publishing and expresses appreciation to authors, reviewers, and readers for their support. The author passes the baton to the next Executive Editor-in-Chief and expresses confidence in the future of MRE. [Extracted from the article]

This investigation employs contemporary computational and numerical techniques to derive analytical and approximate soliton solutions for the Caudrey–Dodd–Gibbon model, which represents a significant variation of the fifth-order Korteweg–de Vries equation. Diverse analytical solutions are constructed, employing distinct formats such as exponential, trigonometric, and hyperbolic functions. Simulations, including two-dimensional, three-dimensional, contour, polar, and discrete plots, are presented to illustrate the real-world behavior of a single soliton. Furthermore, these solutions are utilized to evaluate the essential conditions for implementing the proposed numerical scheme. The agreement between the computed and approximate solutions is demonstrated through various techniques. These results unequivocally establish the superiority of these methods for solving nonlinear mathematical physics problems. [ABSTRACT FROM AUTHOR]

Studying worked examples has been shown by extensive research to be an effective method for learning to solve well-structured problems in physics and mathematics. The effectiveness of learning with worked examples has been demonstrated and documented in many research projects. In this work, we propose a new four-step approach for teaching with worked examples that includes writing explanations and finding and correcting errors. This teaching method can even be implemented in courses in which homework performance constitutes part of the grading system. This four-step approach is illustrated in the context of Lagrangian mechanics, which is ideal for the application of worked examples due to its universal approach to solve problems. [ABSTRACT FROM AUTHOR]

Previously, the infrared permittivity tensor of monoclinic β-Ga2O3 crystals has been determined using ellipsometry reflection measurements from two differently oriented monoclinic β-Ga2O3 crystals with surfaces parallel to (010) and (−201). The (010) surface places the crystallographic a-c plane in the table of the instrument. The permittivity tensor consists of four complex values, and in order to compute it, four or more combinations of measurements are required at selected table rotations and incidence angles. However, the (010) orientation also places the transverse optical (TO) modes with Au symmetry parallel to the z-axis of the instrument, and we find that these modes are not fully excited and, hence, not measurable due to underlying selection rules. This makes additional measurements on surfaces other than (010) necessary. The second orientation has been the (−201) crystal, which places the crystallographic b axis in the plane of the table to access the transverse Au phonons. In prior work, the overall tensor has been determined by combining measurements of the two crystal orientations [Schubert et al., Phys. Rev. B 93, 125209 (2016)]. The goal of the work here is to find single crystal orientations for which all TO modes can be determined from measurements. The use of a set of measurements employed for such a single crystal is inextricably linked to the choice of incidence angles and table rotations. Consequently, determining suitable angles for these is linked to the selection of a crystal orientation, which is, therefore, an integral part of the overall goal. The TO contribution to the permittivity strongly dominates at or near the TO mode wavenumber resonances and, therefore, are used in this work to identify suitable orientations for a single crystal. Any such crystal orientation will also provide measurements useful to compute permittivity across the entire measured wavenumber range. In principle, any crystal orientation that does not place the direction of any TO mode at or near the z-axis may be suitable due to the underlying physics and mathematics of the problem. We discuss which of these measurement parameters contain the most sensitivity for the (111) orientation. For accuracy, we seek the best or very good orientations. Our investigation follows a previously demonstrated approach where at a single wavelength, the full tensor of an orthorhombic absorbing crystal was obtained from a low-symmetry surface of stibnite [Schubert and Dollase, Opt. Lett. 27, 2073 (2002)]. We discuss which of these measurement parameters contain the most sensitivity for the (111) orientation. The methods presented here will also be useful for other monoclinic materials as well as other materials of different crystal structures, including orthorhombic and triclinic materials. [ABSTRACT FROM AUTHOR]

An analytical solution to the sharp-front magnetic diffusion problem with a step-like resistance model is an interesting mathematical physics problem. It also relates to the plasma production at the surface of a metal under strong magnetic loading measured in experiments. In this paper, we make an advance on an earlier work of Xiao et al. [Phys. Plasmas 23, 082104 (2016)], by deriving formulas for the threshold magnetic field strength and the diffusion velocity of the magnetic diffusion wave under a step-like resistance model to the higher order accuracy. [ABSTRACT FROM AUTHOR]

The general obstacle framework has found applications in steady state fluid interaction, thin-plate fluid dynamics, study of minimal surfaces, control theory, elasto-statics, etc. The obstacle problem involving the fractional operator indeed appears in many contexts, such as in the analysis of anomalous diffusion, in the quasi-geostrophic flow problem, and in pricing of American options regulated by assets evolving in relation to jump processes; these notable applications in financial mathematics and physics made the obstacle problem very important in recent times. In this work, we present a fractional contact problem in which derivative of fractional order in the sense of Caputo is involved. Using the penalty function method, we degenerate it into a system of fractional boundary value problems with known obstacle. We apply the variational iteration method (VIM) for finding the series solution of these fractional BVPs. In order to ensure the accuracy and convergence of solution, residual errors of the solutions for various values of fractional parameters are plotted. The quite accurate results show that variational iteration method is one of the highly potential and robust method for solving fractional BVPs. [ABSTRACT FROM AUTHOR]

This will be the final issue of the Patent Reviews edited by Lloyd Rice, who has served in this capacity since 2000. On behalf of the ASA, the Editor in Chief is grateful for his service these many years. The purpose of these acoustical patent reviews is to provide enough information for a Journal reader to decide whether to seek more information from the patent itself. Any opinions expressed here are those of the reviewers as individuals and are not legal opinions. Patents are available via the internet at the USPTO website, and also using Google Patents. [ABSTRACT FROM AUTHOR]

In my last column, I mentioned that, at a high Reynolds number, drag is proportional to speed squared and that this statement can be justified by a dangerous combination of two back-of-the-envelope methods.[1] However, because the layer is thin, the Navier-Stokes equations, Eq. (6), become manageable. As I i goes to zero, the boundary layer gets thinner - and gets seemingly less relevant - but the second derivative (needed to determine the viscous forces) exactly compensates for this decrease, holding the term's magnitude constant. A turbulent boundary layer, because its eddies transfer momentum so efficiently, hugs the object closely, changing the flow pattern outside the boundary layer (compared to a laminar boundary layer) and reducing the drag. [Extracted from the article]

Then, as an added bonus, the authors show how the same mathematics yields the demagnetization factor for a prolate spheroid, a result that is used widely in magnetization measurements but is seldom derived because - until now - the known mathematical approaches were extremely challenging. The authors here take the physics analysis a step further and consider the rigidity of the string to calculate the characteristic frequencies of plucked guitar strings. This material is appropriate for an undergraduate class on wave physics, building a connection with condensed matter physics. [Extracted from the article]

In this paper, we demonstrate that by using a mathematical physics approach--focusing attention on the physics and using mathematics as a tool--it is possible to visualize the formation of the transverse modes inside a cylindrical waveguide. The opposite (physical mathematics) approach looks at the mathematical problem and then tries to impose a physical interpretation. For cylindrical waveguides, the physical mathematics route leads to the Bessel differential equation, and it is argued that in the core of the waveguide there are only Bessel functions of the first kind in the description of the transverse modes. The Neumann functions are deemed non-physical due to their singularity at the origin and are eliminated from the final description of the solution. In this paper, by combining geometric optics and wave optics concepts, we show that the inclusion of the Neumann function is physically necessary to describe fully and properly the formation of the propagating transverse modes. With this approach, we also show that the field outside a dielectric waveguide arises in a natural way. [ABSTRACT FROM AUTHOR]

The purpose of this research is to determine whether the acoustic properties of polydisperse fibrous medium (PDFM) and bidisperse fibrous medium (BDFM) can be modeled by monodisperse fiber media (MDFM) with an effective fiber diameter. Multi-scale numerical simulations on representative elementary volumes of these media are performed to retrieve the transport and geometrical properties governing their acoustic properties. Results show no significant difference between predictions obtained by PDFM or BDFM, and their corresponding effective MDFM. [ABSTRACT FROM AUTHOR]

Markov chain Monte Carlo algorithms are invaluable tools for exploring stationary properties of physical systems, especially in situations where direct sampling is unfeasible. Common implementations of Monte Carlo algorithms employ reversible Markov chains. Reversible chains obey detailed balance and thus ensure that the system will eventually relax to equilibrium, though detailed balance is not necessary for convergence to equilibrium. We review nonreversible Markov chains, which violate detailed balance and yet still relax to a given target stationary distribution. In particular cases, nonreversible Markov chains are substantially better at sampling than the conventional reversible Markov chains with up to a square root improvement in the convergence time to the steady state. One kind of nonreversible Markov chain is constructed from the reversible ones by enlarging the state space and by modifying and adding extra transition rates to create non-reversible moves. Because of the augmentation of the state space, such chains are often referred to as lifted Markov Chains. We illustrate the use of lifted Markov chains for efficient sampling on several examples. The examples include sampling on a ring, sampling on a torus, the Ising model on a complete graph, and the one-dimensional Ising model. We also provide a pseudocode implementation, review related work, and discuss the applicability of such methods. [ABSTRACT FROM AUTHOR]

The article highlights importance of geometric mean. It mentions solution of a physical problem by computing the geometric mean of two relevant scales and presents several example including measurement of distance to the horizon when lifeguard sitting in a high chair; measurement of spin down time while stirring tea; and for calculation of resonant LRC circuit (an inductor L , resistor R, and a capacitor C).

Velocity reciprocity and the relativity principle Patrick Moylan B 90 b (2), p. 126 https://doi.org/10.1119/10.0009219 Velocity reciprocity is the property that pairs of inertial reference frames will measure each other to have equal and opposite relative velocities. This paper analyses the group-theoretic foundations of relativity theory to explore what additional assumptions must be made for velocity reciprocity to hold, and also explores the misconception that velocity reciprocity follows from the relativity of motion principle. Exploring complex pattern formation with convolutional neural networks Christian Scholz and Sandy Scholz B 90 b (2), p. 141 https://doi.org/10.1119/5.0065458 Machine learning is becoming more and more important in the analysis of data in many fields including physics. [Extracted from the article]

The viscosity affects the rate at which air flows through a tube (Poiseuille flow), but both the applied pressure and the flow rate must be accurately measured. Yet another approach to solutions of one-dimensional wave equations with inhomogeneous bounda... Qiong-Gui Lin B 90 b (1), p. 31 https://doi.org/10.1119/5.0058957 Solving the wave equation or the diffusion equation (in one or more dimensions) with appropriate boundary and initial conditions is one of the basic problems in mathematical physics. This approach couples nicely to concepts typically included in the introductory physics sequence, making the Clausius-Clapeyron equation accessible to beginning students. [Extracted from the article]

A numerical modeling method for accurately predicting the acoustophoretic motion of compressible microparticles in microfluidic devices is presented to consider the effects of fluid medium flow and spatial temperature variation that can significantly influence the acoustophoretic motion. In the proposed method, zeroth-order fluid medium flow and temperature, and first- and second-order acoustic fields in the microfluidic devices are first calculated by applying quadratic mapping functions and a second-order finite difference method (FDM) to perturbed mass, momentum, and energy conservation equations and state equation. Then, the acoustic radiation force is obtained based on the Gorkov's acoustic radiation force equation and applied to the Newton's Equation of Motion to calculate the microparticle motion. The proposed method was validated by comparing its results to a commercial software package, COMSOL Multiphysics results, one-dimensional, analytical modeling results, and experimental results. It is shown that the fluid medium flow affects the acoustic radiation force and streaming significantly, resulting in the acoustic radiation force and streaming prediction errors of 10.9% and 67.4%, respectively, when the fluid medium flow speed is increased from 0 to 1m/s. A local temperature elevation from 20 °C to 22°C also results in the prediction errors of 88.4% and 73.4%. [ABSTRACT FROM AUTHOR]

This paper works out an algorithm in a way that provides an interesting example for an intermediate-level mechanics or computational physics course. By invoking the reflection property of the ellipse, calculus is avoided entirely, making this approach ideal for use in introductory physics and astronomy courses. Based on retention in STEM programs, grades in the module and in subsequent STEM courses, and survey/interview data, the course achieved its goals admirably. [Extracted from the article]

A review of student answers to diagnostic questions concerned with Newton's Laws showed a tendency for some students to change their answer to a question when the following question caused them to think more about the situation. We investigate this behavior and interpret it in the framework of the resource model; in particular, a weak Newton's Third Law structure being dominated by an inconsistent Newton's Second Law (or "Net Force") structure, in the absence of a strong, consistent Newtonian structure. This observation highlights the hidden problem in instruction where the implicit use of Newton's Third Law is dominated by the explicit conceptual and mathematical application of Newton's Second Law, both within individual courses and across a degree program. To facilitate students' development of a consistent Newtonian knowledge structure, it is important that instructors highlight the interrelated nature of Newton's Laws in problem solving. [ABSTRACT FROM AUTHOR]

This paper presents an experimental study of the dynamics of a chain sliding off of a table, using video analysis to test a theoretical model. The model consists of two variable-mass subsystems, with friction between the chain and the table and assumes that all links move at the same speed. In order to check the model, the chain position x(t) is obtained using video analysis. The smoothed function x(t) and its derivatives v(t) and a(t) are numerically computed using a local regression algorithm. In this way, the differential equation governing the motion can be directly tested, instead of comparing the position with the solution of the differential equation. Our procedure is very sensitive to deviations between the model and reality, so we can detect the point at which the chain ceases to be in tension and the model is no longer valid. This experiment shows students the limitations of simplified models and offers an opportunity to assess a model's range of validity. [ABSTRACT FROM AUTHOR]

The temporal occurrence of deep diving cetaceans in the Josephine Seamount High Seas Marine Protected Area (JSHSMPA), south-west Portugal, was monitored using a passive acoustic recorder. The recorder was deployed on 13 May 2010 at a depth of 814 m during the North Atlantic Treaty Organization Centre for Maritime Research and Experimentation cruise "Sirena10" and recovered on 6 June 2010. The recorder was programmed to record 40 s of data every 2min. Acoustic data analysis, for the detection and classification of echolocation clicks, was performed using automatic detector/classification systems: M3R (Marine Mammal Monitoring on Navy Ranges), a custom MATLAB program, and an operator-supervised custom MATLAB program to assess the classification performance of the detector/classification systems. M3R CS-SVM algorithm contains templates to detect beaked whales, sperm whales, blackfish (pilot and false killer whales), and Risso's dolphins. The detections of each group of odontocetes was monitored as a function of time. Blackfish and Risso's dolphins were detected every day, while beaked whales and sperm whales were detected almost every day. The hourly distribution of detections reveals that blackfish and Risso's dolphins were more active at night, while beaked whales and sperm whales were more active during daylight hours. VC2015 Acoustical Society of America. [ABSTRACT FROM AUTHOR]

A method of active acoustic resonance interference spectroscopy is introduced for estimation of bubble properties. A modified form of Rayleigh-Plesset equation for forced oscillation of either a single free bubble or elastic shell encapsulated microbubble with attached solids loading is solved by the regular perturbation method for steady oscillatory solutions as a result of small amplitude acoustic excitation by a point sinusoidal oscillator. A model for the total pressure field at an acoustic receiver in an incompressible liquid is then solved by the regular perturbation method. Closed-form analytical solutions are found for pressure power at the acoustic receiver as a function of the excitation frequency and strength; the properties of the bubble, liquid, and encapsulating shell; and the geometry of the active monitoring system. The receiver pressure power exhibits a maximum due to bubble resonance and a minimum due to destructive interference between source and bubble response pressure fields at higher excitation frequencies. The inverse problem is solved to derive unique closed-form analytical estimators for bubble equilibrium size, attached solids mass loading, and encapsulating layer dilatational viscosity as a function of the frequencies of the fundamental resonance maximum, interference minimum, second harmonic maximum total average acoustic power, monitoring system, and phase properties. [ABSTRACT FROM AUTHOR]

This paper compares different approaches to model the vibroacoustic behavior of earmuffs at low frequency and investigates their accuracy by comparison with objective insertion loss measurements recently carried out by Boyer et al. [(2014). Appl. Acoust. 83, 76-85]. Two models based on the finite element (FE) method where the cushion is either modeled as a spring foundation (SF) or as an equivalent solid (ES), and the well-known lumped parameters model (LPM) are investigated. Modeling results show that: (i) all modeling strategies are in good agreement with measurements, providing that the characterization of the cushion equivalent mechanical properties are performed with great care and as close as possible to in situ loading, boundary, and environmental conditions and that the frequency dependence of the mechanical properties is taken into account, (ii) the LPM is the most simple modeling strategy, but the air volume enclosed by the earmuff must be correctly estimated, which is not as straightforward as it may seem, (iii) similar results are obtained with the SF and the ES FE-models of the cushion, but the SF should be preferred to predict the earmuff acoustic response at low frequency since it requires less parameters and a less complex characterization procedure. [ABSTRACT FROM AUTHOR]

The Λ - Φ diagram was a tool introduced in the late 1970s to predict ocean acoustic fluctuation regimes termed unsaturated, partially saturated, and fully saturated, where internal wave sound speed fluctuations play a dominant role. The Λ - Φ parameters reflect, respectively, the strength of diffraction and the root-mean-square phase fluctuation along a ray path. Oceanographic knowledge of the small scale part of the internal wave spectrum and high angle Fresnel zone formulations now allow a more stable and accurate calculation of these parameters. An empirical relation between the variance of log-intensity and Λ - Φ provides a more accurate border between the unsaturated regime and stronger fluctuations. The diagram is consistent with six short range, deep water experiments in the Pacific, Atlantic, and Arctic oceans with frequencies ranging from 75 to 16 000 Hz. The utility of the Λ - Φ diagram is that it provides one of the few means to inter-compare experiments at different geographic locations, and at different frequencies and ranges. [ABSTRACT FROM AUTHOR]

A scalar theory of gravity, extending Newtonian gravity to include field energy as its source, is developed. The physical implications of the theory are probed through its spherically symmetric (source) solutions. The aim is to demonstrate rational physical model building, together with physical and experimental checks of correctness. The theory discussed here was originally considered by Einstein prior to his introduction of general relativity. [ABSTRACT FROM AUTHOR]

This paper proposes a method of creating acoustic contrast control in an arc-shaped area using a linear loudspeaker array. The boundary of the arc-shaped area is treated as the envelope of the tangent lines that can be formed by manipulating the phase profile of the loudspeakers in the array. When compared with the existing acoustic contrast control method, the proposed method is able to generate sound field inside an arc-shaped area and achieve a trade-off between acoustic uniformity and acoustic contrast. The acoustic contrast created by the proposed method increases while the acoustic uniformity decreases with frequency. [ABSTRACT FROM AUTHOR]

This paper describes a methodology and case study for the implementation of educational virtual laboratories for practice training on acoustic tests according to international standards. The objectives of this activity are (a) to help the students understand and apply the procedures described in the standards and (b) to familiarize the students with the uncertainty in measurement and its estimation in acoustics. The virtual laboratory will not focus on the handling and set-up of real acoustic equipment but rather on procedures and uncertainty. The case study focuses on the application of the virtual laboratory for facade sound insulation tests according to ISO 140-5:1998 (International Organization for Standardization, Geneva, Switzerland, 1998), and the paper describes the causal and stochastic models and the constraints applied in the virtual environment under consideration. With a simple user interface, the laboratory will provide measurement data that the students will have to process to report the insulation results that must converge with the "virtual true values" in the laboratory. The main advantage of the virtual laboratory is derived from the customization of factors in which the student will be instructed or examined (for instance, background noise correction, the detection of sporadic corrupted observations, and the effect of instrument precision). [ABSTRACT FROM AUTHOR]

Listeners' ability to discriminate unfamiliar voices is often susceptible to the effects of manipulations of acoustic characteristics of the utterances. This vulnerability was quantified within a task in which participants determined if two utterances were spoken by the same or different speakers. Results of this task were analyzed in relation to a set of historical and novel parameters in order to hypothesize the role of those parameters in the decision process. Listener performance was first measured in a baseline task with unmodified stimuli, and then compared to responses with resynthesized stimuli under three conditions: (1) normalized mean-pitch; (2) normalized duration; and (3) normalized linear predictive coefficients (LPCs). The results of these experiments suggest that perceptual speaker discrimination is robust to acoustic changes, though mean-pitch and LPC modifications are more detrimental to a listener's ability to successfully identify same or different speaker pairings. However, this susceptibility was also found to be partially dependent on the specific speaker and utterances. [ABSTRACT FROM AUTHOR]

Short-time spectral changes in the speech signal are important for understanding noise-vocoded sentences. These information-bearing acoustic changes, measured using cochlea-scaled entropy in cochlear implant simulations [CSECI ; Stilp et al. (2013). J. Acoust. Soc. Am.133(2), EL136-EL141; Stilp (2014). J. Acoust. Soc. Am. 135(3), 1518-1529], may offer better understanding of speech perception by cochlear implant (CI) users. However, perceptual importance of CSECI for normal-hearing listeners was tested at only one spectral resolution and one temporal resolution, limiting generalizability of results to CI users. Here, experiments investigated the importance of these informational changes for understanding noise-vocoded sentences at different spectral resolutions (4-24 spectral channels; Experiment 1), temporal resolutions (4-64 Hz cutoff for low-pass filters that extracted amplitude envelopes; Experiment 2), or when both parameters varied (6-12 channels, 8-32 Hz; Experiment 3). Sentence intelligibility was reduced more by replacing high-CSECI intervals with noise than replacing low-CSECI intervals, but only when sentences had sufficient spectral and/or temporal resolution. High-CSECI intervals were more important for speech understanding as spectral resolution worsened and temporal resolution improved. Trade-offs between CSECI and intermediate spectral and temporal resolutions were minimal. These results suggest that signal processing strategies that emphasize information-bearing acoustic changes in speech may improve speech perception for CI users. [ABSTRACT FROM AUTHOR]

Previous research on the perception, recognition, and learning of sounds and words has identified diverse effects of phonetic variation. The present study examined how variation affects cross-language production of consonant clusters. American English speakers shadowed words beginning with nonnative clusters in low- and high-variability conditions. Shadowing responses in the low-variability condition were quite sensitive to fine-grained phonetic properties that were manipulated across the stimuli. Notably, longer stop bursts led to increased rates of epenthesis, lower burst amplitudes resulted in more feature change and deletion, and intense periods of voicing at cluster onset elicited prothetic responses. Sensitivity to the acoustic manipulations was substantially attenuated in the high-variability condition, which combined stimuli from the first condition with baseline productions of the same items from two additional talkers. Detailed analyses of the response patterns indicate that more stable production targets in the high-variability condition resulted from integration, or blending, of the multiple talker stimuli. Implications of these findings for language-specific speech processing and the role of phonetic variability in second language acquisition are discussed. [ABSTRACT FROM AUTHOR]

This work deals with the duration of voicing and silence periods of continuous speech in rooms with very different reverberation times (RTs). Measurements were conducted using the Ambulatory Phonation Monitoring (APM) 3200 (Kaypentax, Montvale, NJ) and Voice-Care devices (developed at the Politecnico di Torino, Italy), both of which have a contact microphone placed on the base of the neck to detect skin vibrations during phonation. Six university professors and 22 university students made short laboratory monologs in which they explained something that they knew well to a listener 6m away. Seven students also described a map with the intention of correctly explaining directions to a listener who drew the path on a blank chart. Longer speech samples were made by 25 primary school teachers in classrooms. A tendency to increase the voicing periods as the RT increased was on average observed for the university professors, the school teachers, and the university students who described a map. These students also showed longer silence periods than the students who made short monologs. The recognized trends concerned voice professionals or subjects who were highly motivated to make themselves understood in a perturbed speaking situation. Nonparametric statistical tests, which were applied to detect the differences in distributions of voicing and silence periods, have basically supported the findings. [ABSTRACT FROM AUTHOR]

Acoustic-gravity waves in the middle and upper atmosphere and long-range propagation of infrasound are strongly affected by air viscosity and thermal conductivity. To characterize the wave dissipation, it is typical to consider idealized environments, which admit plane-wave solutions. Here, an asymptotic approach is developed that relies instead on the assumption that spatial variations of environmental parameters are gradual. It is found that realistic assumptions about the atmosphere lead to rather different predictions for wave damping than do the plane-wave solutions. A modification to the Sutherland-Bass model of infrasound absorption is proposed. [ABSTRACT FROM AUTHOR]

In this paper, the contribution of visual and acoustic preference to multi-sensory landscape evaluation was quantitatively compared. The real landscapes were treated as dual-sensory ambiance and separated into visual landscape and soundscape. Both were evaluated by 63 respondents in laboratory conditions. The analysis of the relationship between respondent's visual and acoustic preference as well as their respective contribution to landscape preference showed that (1) some common attributes are universally identified in assessing visual, aural and audio-visual preference, such as naturalness or degree of human disturbance; (2) with acoustic and visual preferences as variables, a multi-variate linear regression model can satisfactorily predict landscape preference (R ²=0.740), while the coefficients of determination for a unitary linear regression model were 0.345 and 0.720 for visual and acoustic preference as predicting factors, respectively; (3) acoustic preference played a much more important role in landscape evaluation than visual preference in this study (the former is about 4.5 times of the latter), which strongly suggests a rethinking of the role of soundscape in environment perception research and landscape planning practice. [ABSTRACT FROM AUTHOR]

The problem of delivering personal audio content to listeners sharing the same acoustic space has recently attracted attention. It has been shown that a perceptually acceptable level of acoustic separation between the listening zones is difficult to achieve with active control in non-anechoic conditions. A common problem of strong first order reflections has not been examined in detail for systems with practical constraints. Acoustic contrast maximization combined with optimization of source positions is identified as a potentially effective control strategy when strong individual reflections occur. An analytic study is carried out to describe the relationship between the performance of a 2 x 2 (two sources and two control sensors) system and its geometry in a single-reflection scenario. The expression for acoustic contrast is used to formulate guidelines for optimizing source positions, based on three distinct techniques: Null-Split, Far-Align, and Near-Align. The applicability of the techniques to larger systems with up to two reflections is demonstrated using numerical optimization. Simulation results show that optimized systems produce higher acoustic contrast than non-optimized source arrangements and an alternative method for reducing the impact of reflections (sound power minimization). [ABSTRACT FROM AUTHOR]