bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting underwater radiated noise levels due to the first offshore wind turbine installation in the United States
Authors: Kim Huikwan , Miller James H. , Potty Gopu R.
Published: May 2013

Noise generated by offshore impact pile driving radiates into the air, water, and sediment. Predicting noise levels around the support structures at sea is required to estimate the effects of the noise on marine life. Based on high demands developing renewable energy source, the United States will begin the first pile driving within one to two years. It is necessary to investigate acoustic impact using our previously verified coupled Finite Element (Commercial FE code Abaqus) and Monterey Miami Parabolic Equation (2D MMPE) models [J. Acoust. Soc. Am. 131(4), 3392 (2012)]. In the present study, we developed a new coupled FE-MMPE model for the identification of zone of injury due to offshore impact pile driving. FE analysis produced acoustic pressure outputs on the surface of the pile, which are used as a starting field for a long range 2D MMPE propagation model. It calculates transmission loss for N different azimuthal directions as function of distance from the location of piling with the inputs of corresponding bathymetry and sediment properties. We will present predicted zone of injury by connecting N different distances of equivalent level fishes may get permanent injury due to the first offshore wind farm installation in the United States.
Airfoil flow and noise computation using monotonically integrated large eddy simulation and acoustic analogy: Effect of the grid resolution
Authors: Semiletov Vasily A. , Karabasov Sergey A.
Published: May 2013

A new scalable Monotonically Integrated Large Eddy Simulation (MILES) method based on the Compact Accurately Boundary-Adjusting high-REsolution Technique (CABARET) has been applied for the simulation of unsteady flow around NACA0012 airfoil at Re = 400,000 and M = 0.058. The flow solution is coupled with the Ffowcs Williams–Hawkings formulation for far-field noise prediction. The computational modeling results are presented for several computational grid resolutions: 8, 16, and 32 million grid cells and compared with the experimental data available.
The simulation of the seismoelectric logging while drilling based on elastic model
Authors: Zheng Xiaobo , Liu Xien , Hu Hengshan , Guan Wei
Published: May 2013

In recent years, the acoustic LWD technology which is drilling and logging at the same time has been developing rapidly. However, the collar wave could cover or interfere with signals from the formation to affect the extraction of P and S wave velocities in the sonic logging. In order to solve this problem, this paper makes a research about the seismoelectric LWD response. In this study, we use the decoupling algorithm to calculate seismoelectric field in the borehole. We can obtain the elastic sound field by solving the wave equation first, and then calculate the electromagnetic field excited by the sound field by using the Pride control equations. Although using the elastic model in the calculation, we simulate the attenuation effect of pore formation by introducing quality factor and gain the pressure of the fluid within the pore by introducing the Skempton factor. Finally, this paper shows the full waveforms of the electromagnetic and acoustic fields excited by multipole source. We find that the collar wave in the electric field is significantly weakened compared with that in the acoustic pressure, in terms of its amplitude relative to the other wave groups in the full waveforms.
Effect of percussion impulse sounds on hearing
Authors: Pazen David , Beutner Dirk , Walger Martin
Published: May 2013

Impulse-like sounds with high peak pressure levels emitted by percussion instruments often occur in music. The potentially harmful effect to the inner ear caused by these sounds is not fully understood. Solely the physical description of impulses like peak pressure level, etc. is not considered meaningful enough to assess their hazard. Therefore, the Auditory Hazard Assessment Algorithm for Humans (AHAAH), which is based on a physiological model, seems to be more appropriate. Another quantity to assess auditory hazard is the change of otoacoustic emissions (OAEs) after a sound exposure. It allows the individual detection of small physiological changes of the outer hair cells before any serious damages and threshold shifts may occur. In a pilot experiment the sounds of several percussion instruments have been measured at the players’ ears in a regular rehearsal situation. To assess the auditory hazard of the measured sounds the players’ OAEs have been measured before and after playing on the instruments. Despite peak levels of about 140 dB, the OAEs did not change significantly and the AHAAH rated nearly all sounds as harmless. It can be concluded that impulse sounds in music with high peak levels are not necessarily hazardous.
Efficient estimates of cochlear hearing loss parameters in individual listeners
Authors: Fereczkowski Michal , Jepsen Morten L. , Dau Torsten
Published: May 2013

It has been suggested that the level corresponding to the knee-point of the basilar membrane (BM) input/output (I/O) function can be used to estimate the amount of inner- and outer hair-cell loss in listeners with a moderate cochlear hearing impairment [e.g., Plack et al., (2004)]. In the present study, results from forward masking experiments based on temporal masking curves [TMC; Nelson et al. (2001)] are presented and used to estimate the knee-point level and the compression ratio of the I/O function. A time-efficient paradigm based on the single-interval-up-down method [SIUD; Lecluyse and Meddis (2009)] was used instead of an alternative forced-choice paradigm. In contrast with previous studies, the present study used only on-frequency TMCs to derive estimates of the knee-point level. Further, it is explored whether it is possible to estimate the compression ratio using only on-frequency TMCs. Ten normal-hearing and 10 hearing-impaired listeners (with mild-to-moderate sensorineural hearing loss) were tested at 1, 2, and 4 kHz. The results showed a reasonable reliability and an increased time-efficiency compared to AFC-based results and may be suitable for individualized hearing-aid fitting.
Relationship of distortion product otoacoustic emission components to psychoacoustic measures of noise induced hearing loss
Authors: Coad Gavin , Long Glenis R. , Welch David , Thorne Peter R.
Published: May 2013

Distortion product otoacoustic emissions (DPOAEs) have promise as a tool to detect and monitor cochlear hair cell damage in noise induced hearing loss (NIHL). However, variability in OAE amplitudes and thresholds across individuals limits their potential for detecting the early impact of NIHL. The DPOAE has two components, one generated at the point of interaction between the primaries (generator), the second reflected from the characteristic place of the DPOAE frequency (reflected). There has been increasing interest in looking at the components of the DPOAE and how they correlate with injury. A total of 109 men, including 57 with varying degrees of occupational noise exposure, were tested. We recorded DPOAEs using logarithmically swept pure tones and extracted the components of the DPOAE using a least-squares fit approach. Pure-tone audiometry was conducted at 1.5 and 4 kHz with 1dB resolution. Compressive nonlinearity was evaluated psychoacoustically with 1.5 and 4 kHz pure-tones using Schroeder phase maskers. Overall there are associations between the generator component and the psychoacoustic measures: stronger DPOAE amplitudes were associated with better audiometric thresholds and greater difference in Schroeder masking threshold. Associations were stronger at 4 than 1.5 kHz. Similar, but weaker effects were observed for the reflected component. Findings suggest that separation of DPOAE components enhances the assessment of cochlear noise-induced injury.
Modeling human auditory evoked brainstem responses to speech syllables
Authors: Harte James , Roenne Filip M. , Dau Torsten
Published: May 2013

Auditory evoked brainstem responses (ABR) are routinely used to assess the neural encoding of sound. Various types of stimuli have been historically considered, and there is a current increasing trend towards the use of syllables, speech and complex (non-speech) sounds. Despite the peripheral origin of ABRs, the nonlinear processing within the cochlea and brainstem makes interpreting responses to these new stimuli a challenge. A recent model was developed [Ro/nne et al. (2012)] to simulate ABRs to transient sounds such as tone pulses, clicks and rising chirps as a function of stimulus level. The present study extends this model to simulate synthetic /ba/, /da/ and /ga/ syllable-evoked ABRs, where the stimuli only differ in their spectral energy of the second formant, f2, within their first 60 ms. The model takes the convolution of the instantaneous discharge rates using a “humanized” nonlinear auditory-nerve model of Zilany et al. (2009) and an empirically derived unitary response function, assumed to reflect contributions from different cell populations within the auditory brainstem. The ABR model was used to explore the physiological basis and spectro-temporal characteristics of key features observed in syllable-evoked ABRs in the literature [Skoe et al. (2011), Hornickel et al. (2009)].
Understanding informational masking from a neural perspective
Authors: Shinn-Cunningham Barbara
Published: May 2013

Historically, psychoacousticians have divided the influence of a task-irrelevant sound (a masker) on perception of a task-relevant sound (the target) into components of (1) energetic masking and (2) informational masking. In this apportionment, energetic masking is defined as that masking that can be accounted for by considering how reliably the target is represented in the auditory periphery, and how much the masker disrupts this target representation. In contrast, the term informational masking is a catchall representing any effects of the masker that could not be accounted for by energetic masking. This talk presents a framework for understanding informational masking from a neural perspective, building on both behavioral results and neuro-imaging data. In this account, informational masking is a result of bottlenecks in the neural processing of acoustic information, a problem that the brain mediates by engaging auditory attention. Auditory attention operates by modulating the representation of different auditory objects making up a particular acoustic scene, resulting in a relative enhancement of whatever object is in the attentional foreground at the expense of the representation of competing sources. Thus, most informational masking arises from failures of target formation and/or failures of target selection.
Nonstationary vibration analysis in the smoothed Wigner domain
Authors: Galleani Lorenzo
Published: May 2013

Dynamical systems represent fundamental models for vibration analysis. When the input of such dynamical systems is nonstationary also the output is nonstationary, and its frequency content changes with time. Time-frequency analysis provides an effective representation of this time-varying spectrum. Even more effective is the direct time-frequency representation of dynamical systems. We first show how to transform a dynamical system in the domain of the smoothed Wigner distribution. The result is a time-frequency dynamical system whose input and output are the smoothed Wigner distributions of the input and output signals in time, respectively. Then, we illustrate how to compute the smoothed Wigner output when the input to the dynamical system in time belongs to a class of common nonstationary inputs, including a delta function and a short duration sinusoid. Finally, we show how to obtain the smoothed Wigner output when the input is a linear combination of these nonstationary signals. We provide a series of examples that show how the time-frequency representation of dynamical systems can unveil the spectral structure of nonstationary vibrations.
A single-crystal acoustic hydrophone for increased sensitivity
Authors: Brown Jeremy , Dunphy Kevin , Beslin Olivier
Published: May 2013

This study describes the development of a underwater surveillance hydrophone based on next generation PbMg1/3Nb2/3O3-PbTiO3 (PMN-PT) single-crystal piezoelectric as the hydrophone substrate. Although PMN-PT can possess much higher piezoelectric sensitivity than traditional PZT piezoelectrics, it is highly anisotropic and therefore there is a large gain in sensitivity only when the crystal structure is oriented in a specific direction. Because of this, simply replacing the PZT substrate with a PMN-PT cylinder is not an optimal solution because the crystal orientation does not uniformly align with the circumferential axis of the hydrophone. Therefore, we have developed a novel composite hydrophone that maintains the optimal crystal axis around the hydrophone circumference. An 11.3 mm diameter composite hydrophone cylinder was fabricated from a single <110> cut PMN-PT rectangular plate. Solid end caps were applied to the cylinder and the sensitivity was directly compared with a solid PZT-5A cylindrical hydrophone of equal dimensions in a hydrophone test tank. The charge sensitivity showed a 7.5 dB improvement over the PZT hydrophone and the voltage sensitivity showed a 2.7 dB improvement. This was in relatively good agreement with the theoretical improvements of 12.88 dB and 5.44 dB, respectively.
Laboratory investigation with subbottom parametric echosounder SES-2000 standard with an emphasis on reflected pure signals analysis
Authors: Szymczak Wojciech , Grelowska Grazyna , Kozaczka Eugeniusz , Kozaczka Sławomir
Published: May 2013

The main goal of the paper is to describe correlations between measurements results of trials taken on Guls of Gdańsk bottom sounded with parametric echosounder SES-2000 Standard and laboratory research where collected during survey sediments were measured. Stationary tests took place at Gdańsk University of Technology where 30 meters long 1.8 meter deep and 3 meters wide water tank is located. Main lobe of antenna was directed parallel to the longest dimension. Hydrophones used during experiment were fixed to the 3D positioning system—ISEL, which gave the opportunity to place sensor with high precision in the middle of main lobe or other specified places. Using prepared to this experiment frames different sea bottom layers configurations corresponding to the natural structure were sounded. Data obtained during laboratory measurements and trials in situ were combined to draw conclusions about proper interpretation of echograms and begin the process of sediments classification. Analyses were done with Matlab programing software were data were imported and used to the simulations and comparisons.
A statistical analysis of acoustical measurement uncertainties for assemblies within multi-family dwellings in the United States
Authors: Dong David W. , LoVerde John
Published: May 2013

Over the last several years, the authors have demonstrated that the uncertainties in the methods of acoustical testing are much larger than realized by professionals and lay people [LoVerde and Dong, J. Acoust. Soc. Am. 125, 2629 (2009); J. Acoust. Soc. Am. 126, 2171 (2009); J. Acoust. Soc. Am. 130, 2355 (2011)]. Acceptance of the large uncertainty immediately raises many practical questions. How much of the uncertainty is inherent in the test procedure and how much is due to differences between laboratories, installation methods, contractors, materials, etc.? Is the data hopelessly chaotic, or is there “true value” that can be obtained by suitable data processing? How many tests are required to feel confident in the characterization of an assembly? Some rules of thumb have been developed based on our experience [LoVerde and Dong, J. Acoust. Soc. Am. 131, 3319 (2012)], but these questions have not yet been systematically addressed before. A statistical analysis has been performed using a database of thousands of laboratory and field noise isolation tests. Results are presented that address these questions.
Building information modeling and the consultant: Managing roles and risk in an evolving design and construction process
Authors: Philipp Norman H.
Published: May 2013

Paramount changes are occurring within the building and construction industries, fueled by the ever expanding abilities of computer modeling technologies. This revolution not only impacts our approach to and execution of the physical design of a building, but also the construction and the day to day management of the facilities. Current technologies have allowed the Building Information Modeling (BIM) process to replace many of the time tested design methods of the past. With this shift to new technologies also come new risks which require recognition by the acoustical consultant to ensure our evolution to meet the new paradigm of the current design environment. In this paper the importance of understanding the purpose and role of a BIM implementation/execution plan will be covered inclusive of defining the role, responsibilities, and risks associated with the acoustical consultant.
Toward subsurface positioning of gliders using fixed acoustic tomography sources
Authors: Van Uffelen Lora J. , Nosal Eva-Marie , Howe Bruce M. , Carter Glenn S. , Worcester Peter F. , Dzieciuch Matthew A. , Heaney Kevin D. , Campbell Richard L. , Cross Patrick S.
Published: May 2013

Acoustic Seagliders can be positioned precisely using GPS at the surface, but are underwater and unable to utilize GPS for up to 9 h at a time as they dive to depths of up to 1000 m. During this time, a kinematic model estimates the position of the glider. Four acoustic Seagliders were deployed in the Philippine Sea November 2010–April 2011, and received transmissions from five broadband acoustic tomography sources moored in the region. Over 2000 acoustic receptions were recorded at ranges up to 700 km from the moored sources. Measured acoustic arrival peaks were unambiguously associated with ray arrivals predicted using the model-estimated glider position at the time of reception and a mean sound-speed profile. Estimates of source-receiver range uncertainty were calculated from statistics of travel-time offsets between the measured arrivals and the eigenray dispersion patterns. The uncertainty in range between the source and the modeled glider position during a dive is estimated to be 639 m (426 ms) rms disregarding the effects of ocean sound-speed variability, which are anticipated to be on the order of 70 ms rms.
RoBin - A one-man measurement system for standard acoustic emission measurement according to IEC 61400-11
Authors: Vaucher de la Croix Daniel , Klaas Timo
Published: May 2013

Wind turbines are built at more and more locations—which makes their noise emission an important subject. The international standard IEC 61400-11 and the German Technische Richtlinie fur Windenergieanlagen, Teil of the FGW were set up in order to unify the evaluation of noise emission. Measurement of noise emission according to these standards is linked to formidable challenges, especially for the installation of testing equipment and evaluation of data. After a short reminder on the ISO 61400 standard, the proposed paper will discuss the details of operational constraints linked with on-site measurements and how modern communication technologies help in an easy system deployment and most efficient operation for the benefits of its users.
A review of road traffic barriers for low frequency noise
Authors: Fard Samaneh M. , Kessissoglou Nicole , Samuels Stephen , Burgess Marion
Published: May 2013

Australia relies heavily on road transport due to its large area and low population density in many parts of the country. Trucks and heavy vehicles are commonly used for road freight. In addition to their normal vehicle brakes, heavy vehicles are typically fitted with release engine brakes which operate by causing the engine to act as a compressor when braking. Compression braking generates a distinct low frequency rumble that can heard at large distances and is a major source of community annoyance reactions against the heavy vehicle industry. Noise from compression brakes is an on-going cause of complaint from many Australian residents, particularly in rural areas and at night-time. Noise barriers can be used to reduce the spread of general traffic noise and their effectiveness is determined by many factors. This paper presents a review of barriers optimized for road traffic noise and the frequency ranges at which the various barrier designs are most efficient, with a view to selecting the barriers that may be more effective at reducing the low frequency noise from compression brakes.
Engine sounds of small boats at night transmitted to room in apartment built along canal
Authors: Muto Kenji , Akahira Toru
Published: May 2013

In this paper, we show the measurement results of the engine sounds of small boats that cruise in a canal. The canal that is called an Toyosu canal is in the residential area in Tokyo in Japan. It is a canal with the role of the waterway traffic in Tokyo. The engine sounds were measured there from October to November in 2011. There were a lot of tugboats or tugboats pulling a freighter in daytime. There were a lot of fishing boats day and night, and there were a lot of houseboats at night. Many of engine sounds were sound exposure level around Lae = 80 dB. The level of the the greatest was more than sound exposure level Lae = 90 dB. Especially, the most of boats were passed in the morning and evening. They passed in the early morning when the background noise was 50 dB. They passed while obstructing the conversation or waking up. It was a sound with the influence for the inhabitant by the canal. It was shown the result of the engine sound transmitted to the room. The engine noise of the boat was transmitted to the canal side room with high level. These results was described in this paper.
Improvement of the acoustic environment inside the high-speed train stations depending on the increase of the speed
Authors: Haan Chan Hoon , Park Chan Jae
Published: May 2013

The speed of trains has been increased due to the development of railway technologies. Recently, operation speed up to 400 km/h is come to effect in Korea. But, it can be easily predicted that noise and vibration could be increased depending on the speed of trains. Especially, train stations are exposed to much noises for 24-h at the nearest place when high-speed trains stop or pass the terminals. In the present study, noise levels of the passing high-speed trains were measured in four different stations and noise levels at the speed up to 400 km/h were calculated. Also, the predicted noises were analyzed and compared with the interior noise criteria (NC-curve). As a result, it was found that the noise levels exceed 10 dB higher than the noise standards in average when train speed was 350 km/h. Based on the results, some design proposals are suggested to satisfy with the noise standards including reinforcement of walls and ceilings, change of finishing materials, which can improve the sound insulation of rooms in the train stations.
Possibility of sound environmental design by introducing wave sound into the indoor space
Authors: Terashima Takane , Shimahashi Kazuhiro
Published: May 2013

The purpose of this study is to develop the means of designing sound environment of waterfront area. As one of the means of improving sound environment in the campus space of our university, introducing wave sound from the adjoining seashore into campus area has been proposed and its feasibility have been studied. But wave sound reaches 300 m inland at most and cannot be listened in the most of campus area outdoor. So we plan to introduce wave sound by picking up through microphone and steaming over the campus LAN. In this report, if wave sound is streamed and broadcasted to indoor spaces, the influence of wave sound as background/masking noise on the mental state of users in the space is studied. The samples of various wave sound recorded at seashore near the campus are broadcasted in indoor spaces, such as cafeteria, learning spaces, etc. And subjects are asked to answer the questionnaire about preference and subjective impression for indoor environment. The results show that wave sound is almost accepted by users, but to be recognized by uses, output level must be high and could be harmful. The optimum level of wave sound in the space is discussed.
A design of control signal in reducing discomfort of the dental treatment sound based on auditory masking
Authors: Suhara Yuko , Ikefuji Daisuke , Nakayama Masato , Nishiura Takanobu
Published: May 2013

In dental treatment, patients feel a strong discomfort feeling by the treatment sounds which arise by a tooth grinding. In order to add comfort to quality of life, we aim to reduce the discomfort feeling with dental treatment sounds. We previously proposed the unpleasantness reduction method based on auditory masking to reduce discomfort feeling of noise. The previously proposed method can reduce discomfort feeling by emitting a control signal to a listener, but we had focused on unpleasantness reduction to noise which has a peak frequency. Meanwhile, dental treatment sounds tend to consist of multiple spectral peaks. Therefore, in the present paper, we propose the design method of control signals for reducing discomfort feeling of dental treatment sounds which have multiple spectral peaks. More specifically, we detect the main spectral peaks, which bring a discomfort feeling, and design the control signal, which can mask these spectral peaks. Also, we employ the sound of running water as a source for the control signal. We carried out subjective evaluation experiments to confirm the effectiveness of the proposed method. As a result of evaluation experiments, we confirmed the effectiveness of the proposed method.
Noise in hospitals as a strain for the medical staff
Authors: Siegmann Silvester , Notbohm Gert
Published: May 2013

Noise research in hospitals focuses mainly on the harmful effects on patients. But at least in intensive care units and operation theaters, also the staff is exposed to high levels of noise during considerable portions of working time. Evidence from literature is summarized here. During operation sessions lasting from 30 min to several hours, reported average Leq values range from 58 to 72 dB(A) with maximum levels above 105 dB(A). Similar noise levels are reported from emergency departments. As concentration, precise communication, and fast decisions are necessary in these situations, the acoustical environment has to be considered an enormous strain for the staff and a potential risk with regard to faults at work. But also during normal day and night shifts in intensive care units, noise is mentioned as an important disturbance by the medical staff. Most disturbing are noises from telephones and other communication tools and the signals and sounds from medical devices. Questionnaire surveys result in 80 to 91% of the staff reporting negative effects of noise in their daily work. A variety of measures for noise reduction and prevention in hospitals is suggested in literature emphasizing that the staff plays a decisive role in such projects.
Green cork-based innovative resilient and insulating materials: Acoustic, thermal, and mechanical characterization
Authors: Caniato Marco , Orfeo Sbaizero , Kaspar Jan , Di Monte Roberta
Published: May 2013

Nowadays, efficient thermal insulation is a principal requirement for buildings and, accordingly, huge amounts of insulators are applied in the constructions, particularly for external walls, radiant floor, etc. Acoustic insulation is another of the most stringent parameters to be taken into account both in the construction of new buildings or their rejuvenation in order to obtain good internal comfort. On the other hand, the use of bio-derived construction materials is gaining stronger and stronger interest. Cork has a low density (120–240 kg m3) and can be regarded as a hydrophobic and viscoelastic material, with good thermal and acoustic insulation properties. With respect to wood, it presents good resistance to microbial activity and water. Last but not least is the negative carbon fingerprint of cork-based materials. Here we will describe a new class of polymer—inorganic oxides—cork composites that feature enhanced thermal and acoustic properties with respect to traditional commercial composites and maintain, at the same time, all the favorable properties of conventional cork-base composites.
Impulse response measurement in public space using musical signal including swept-sine signals
Authors: Satoh Fumiaki , Mori Junichi , Nishii Tomoya , Tachibana Hideki
Published: May 2013

In design of public spaces, e.g., railway stations, airport terminal buildings, and underground shopping centers, careful attention should be paid from an acoustical viewpoint. It is not only for acoustical comfort but also for safety ensured by a public address system with high intelligibility. As a study for this aim, we have been investigating acoustical characteristics of various public spaces. In these studies, it is strongly desired to measure impulse responses in the spaces under live condition with occupants but the usual measurement method using Swept-Sine signals are not applicable because the signals sound very peculiar to the occupants. To mitigate such a problem, we are trying a method using test music signals in which Swept-Sine signals are inserted. In this paper, the availability of this measurement technique is outlined and some measurement results are introduced.
Unrelaxed drained bulk modulus for fluid-saturated rocks on full frequency range
Authors: Song Yong J. , Hu Hengshan , Li Changwen
Published: May 2013

Local flowing between cracks and pores is called squirt-flow that usually induce elastic moduli dispersion and waves attenuation. Expression of unrelaxed drained bulk modulus on full frequency range is derivated in this paper when liquid pressure in soft crack is unrelaxed. Unrelaxed drained bulk modulus’s real part increases with frequency, and unrelaxed drained bulk modulus’s imaginary part is nonzero. This studies also show that liquid pressure in cracks equals to zero at he low frequency limitation, that is to say liquid pressure in cracks have sufficient time to relax and in this case the drained bulk modulus correspondents to Biot’s static drained bulk modulus.At the high frequency limitation, the unrelaxed drained bulk modulus approximate to Mavko-Jizba’s expression. The expression of drained modulus in this paper also degenerates to Biot theory’s drained bulk modulus when crack density equals zero, but the latter is just a modulus on a hypothetical state and is not the true static experiment data when rocks contain soft cracks. Unrelaxed drained bulk modulus is used to calculate fast P-wave and slow P-wave velocities and attenuation instead of static drained or dry bulk modulus in Biot’s theory. Squirt-flow generates much more velocity dispersion and attenuation in fast P-wave than Biot flow. The magnitude of attenuation depends on crack density and the relaxation frequency depends on aspect ratio.
Compression of perceived auditory space during forward self-motion
Authors: Sakamoto Shuichi , Teramoto Wataru , Furune Fumimasa , Suzuki Yôiti , Gyoba Jiro
Published: May 2013

Humans can perceive a stable auditory environment and appropriately react to a sound source, even when they are moving. This suggests that the inputs are reinterpreted in the brain, while being integrated with information on the movements. Although several studies have shown the influence of the vestibular semicircular canal signals on auditory localization, it is not clear how auditory space representation is modulated by linear accelerations which are obtained from the macular receptors of the otolith system (utricle and saccule). We investigated the effect of the linear acceleration on auditory space representation. During the forward/backward self-motion, a short noise burst was presented from one of the loudspeakers which were aligned parallel to the motion direction when the listener's coronal plane reached the location of one of the speakers (null point). The results showed that the sound position aligned with the subjective coronal plane was displaced ahead of the null point only during forward self-motion. Moreover, all the sounds that were actually located in the traveling direction were perceived as being biased towards the null point. These results suggest a distortion of perceived auditory space in the direction of movement during forward self-motion.
Squeal noise generated by railway disc brakes: Experiments and stability computations on large industrial models
Authors: Chiello Olivier , Sinou Jean-Jacques , Vincent Nicolas , Vermot des Roches Guillaume , Cocheteux Franck , Bellaj Selim , Lorang Xavier
Published: May 2013

The squeal noise generated by railway disk brakes is an everyday source of discomfort for the passengers both inside and outside the trains in stations. The development of silent brake components is needed and requires a better characterization and understanding of the phenomenon. This is the aim of the experimental and numerical investigations performed in the framework of the French AcouFren project and presented in this paper. The first part is concerned with the analysis of experimental data coming from bench tests in a lot of braking configurations including different brake pads. In the second part, the measurements are compared with the results of a large FE model of the brake taking into account the mechanical complexity of each component, especially the brake pads. Components models have been previously updated using experimental modal analysis but the whole model is a direct assembling of it, without updating. The assumption of unilateral contact and Coulomb friction at the pad/disc interface is sufficient to destabilize the sliding equilibrium of the brake and lead to self-sustained vibrations. Complex vibrating modes are computed in order to describe and understand the dynamic instabilities.
Acoustical Society of America Helmholtz-Rayleigh Interdisciplinary Silver Medal in Biomedical Acoustics, Physical Acoustics, and Acoustical Oceanography
Authors: Leighton Timothy J.
Published: May 2013

The Silver Medal is presented to individuals, without age limitation, for contributions to the advancement of science, engineering, or human welfare through the application of acoustic principles, or through research accomplishment in acoustics.
Sensory evaluation of concert hall acoustics
Authors: Lokki Tapio
Published: May 2013

Consumer products can be perceived in many ways, and individual taste influences quality judgments. Sensory evaluation techniques have been developed to reveal detailed information about perception of products; recently, sensory evaluation has also been shown to be very useful in subjective evaluation of concert hall acoustics. In particular, individual vocabulary based methods have helped to disentangle the detailed perceptual differences between the different seats within a hall and between different halls. For simultaneous and accurate comparison of acoustics, a symphony orchestra needs to play identically in each hall. Therefore, a symphony orchestra simulator has been developed. It consists of 34 loudspeakers reproducing synchronized recordings of individual musicians playing parts of symphonies in an anechoic chamber. In addition, an advanced spatial sound recording technique via impulse responses from a 3D microphone array is applied to reproduce the acoustics of a concert hall in laboratory conditions. Analysis of spatial impulse responses also enables spatio-temporal visualization of sound energy distributions at measured seats, thus helping us to link the physical properties of the sound to the perception and architecture of concert halls. Finally, this paper highlights our recent results to explain which perceptual characteristics of acoustics drive preference ratings.
Toward a full-bandwidth numerical acoustic model
Authors: Hargreaves Jonathan , Lam Yiu W.
Published: May 2013

Prediction models are at the heart of modern acoustic engineering. Current commercial room acoustic simulation software almost exclusively approximates the propagation of sound geometrically as rays or beams. These assumptions yield efficient algorithms, but the maximum accuracy they can achieve is limited by how well the geometric assumption represents sound propagation in a given space. This comprises their accuracy at low frequencies in particular. Methods that directly model wave effects are more accurate but they have a computational cost that scales with problem size and frequency, effectively limiting them to small or low frequency scenarios. This paper will report the results of initial research into a new full-bandwidth model which aims to be accurate and efficient for all frequencies; the name proposed for this is the “Wave Matching Method.” This builds on the Boundary Element Method with the premise that if an appropriate interpolation scheme is designed then the model will become “geometrically dominated” at high frequencies. Other propagation modes may then be removed without significant error, yielding an algorithm which is accurate and efficient. This paper will present the general concepts of wave matching and the results from some numerical test cases.
Simulation of non-locally reacting boundaries with a single domain boundary element method
Authors: Opdam Robertus , de Vries Diemer , Vorländer Michael
Published: May 2013

The significance of taking into account non-locally reacting behavior of boundaries compared to the often-used locally reacting assumption in room acoustics has not been extensively investigated. To make this possible a boundary element method is developed, inspired on a seismic simulation method known as the WRW method. The novelty of this method compared to other boundary element methods (BEM) is that the calculation is performed in only one domain. There is no need for a fluid-structure coupling, which in general allows faster simulation times. The theory of the method is presented and some example structures are simulated with both locally and non-locally reacting behavior. The results are shown and discussed.
A diffusion equation model for investigations on acoustics in coupled-volume systems
Authors: Jing Yun , Xiang Ning , Navarro Juan M. , Jing Yun
Published: May 2013

Coupled-volume rooms remain as one of the most exciting and challenging research lines in room acoustics. Their benefits lie on their multiple-slope energy decay profiles, being of interest in many current concert halls. However, so far there is no consistent predictive model being able to help architects and acousticians in selecting appropriate design parameters. This work is devoted to studying effects of aperture-size and source/receiver positions on the energy decay characteristics. For this purpose, a diffusion equation model is used to model a coupled-volume system, providing an effective tool for analysis. The diffusion equation model is first validated by experimental investigations using scale models. Bayesian energy decay analysis is applied to the results of both the acoustical scale model and the diffusion-equation model to provide deeper insight in the energy decay characteristics and their dependence on the aperture sizes and the sound source/receiver positions.
The contributions of pairs of parallel surfaces in a simple analytical model of room reverberation
Authors: Embrechts Jean-Jacques
Published: May 2013

In a recent paper [Embrechts, “Searching for a theoretical relation between reverberation and the scattering coefficients of surfaces in a room,” in Proceedings of the Acoustics 2012 Nantes Conference (2012), 2397–2402], we derived an analytical model of the sound energy decay in a room from the acoustic radiative transfer equation. This model includes the surfaces' scattering properties and it is presently valid for rooms in which the cloud of image sources is approximately isotropic and constant for all receptor's positions. Its validity is extended in this paper by the inclusion of a pair of parallel surfaces. Indeed, it is known that parallel surfaces can introduce significant anisotropy in the cloud of image sources. We show that the room reverberation can be represented by a sum of exponential decays (except in its early part), each decay having its specific slope and amplitude depending on the surfaces' absorption and scattering properties. It is also shown how this simple model can be applied to speed up geometrical acoustics computer simulations.
Achieving optimal reverberation time in a room, using newly patented tuning tubes
Authors: Schnitta Bonnie
Published: May 2013

The aging population has several acoustic requirements in order to optimize their ability to hear better, as well as feel better, in a room. First, there is the requirement that the reverberation time of the room must be reduced in order to assist in hearing. Secondly, there needs to be a lowering of the NC in order to increase the SNR. Increasing the SNR not only helps to assist in hearing, but also reduces some hearing aid problems. In addition to these two standard room requirements, there is also a need for the reduction of lower frequency sounds within a room, such as sounds typical of mechanical equipment. Recent data support the fact that there is a correlation between certain diseases and low frequency intolerance. Since standard products used to absorb sound have a greater absorption in speech frequencies there is a need for products that have greater absorption in lower frequencies. Ideally, these products should also be washable. This paper presents detail on each of this requirements, as well as recommendations on methods to achieve each requirement.
Optimizing the signal to noise ratio in speech rooms using passive acoustics
Authors: D'Antonio Peter
Published: May 2013

Adults with normal hearing require roughly a 0 dB signal-to-noise ratio for good speech intelligibility. However, significantly higher values may be needed to compensate for neurological immaturity, sensorineural and conductive hearing losses, language proficiency and excessive reverberation. ANSI 12.60 addresses ways to lower the noise interference due to background levels and reverberation time. However, it is also possible to increase the signal, by reflecting or diffusing early reflections. Speech intelligibility is delivered in the consonants, which occur in the 2–6 kHz frequency range. Therefore, intelligibility can be enhanced by incorporating scattering surfaces, rather than solely surfaces that absorb sound in the 2–6 kHz region, on the front wall, lower side walls, and central ceiling areas, to increase the speech signal by temporal fusion. The decay time can be controlled with broadband absorption on the perimeter of the ceiling and upper wall surfaces. Since ceiling diffusion is an important design ingredient and the ceiling plane is coveted by many trades, including lighting, HVAC, speakers, sprinklers, etc., we will describe a 24 VDC combined LED lighting and sound diffusor, with a 24 VDC emergency lighting central battery system, dynamic lighting capability, and the ability to incorporate sonic actuators for announcements.
A holistic approach to room design for hearing impaired populations
Authors: Levins Jennifer
Published: May 2013

Acoustic design considerations for hearing impaired populations are widely misunderstood outside of the acoustics community. Some clients have even expressed the sentiment that room acoustics are not important because their patrons are hard of hearing. Contrary to this widely held belief, acoustical design is more critical for these populations. To properly design spaces for these communities, it is imperative to take a holistic approach, which considers not just architectural acoustics, but incorporates an understanding of the biological and psychological components of hearing impairment. It is also important to consider how room systems can be integrated with modern hearing technology. Addressing room acoustics, background sound levels, and audio technology should all be considered in the strategy of designing for hearing impaired persons. This is important not only for their comfort, but also for their health. Strategies and implications for a holistic approach will be discussed.
The effects of sound in the marine environment workbench: A simulation tool to predict the impact of anthropogenic sound on marine mammals
Authors: Mountain David C. , Anderson David , Voysey GraHam , Brughera Andrew
Published: May 2013

The Effects of Sound in the Marine Environment (ESME) Workbench is a software tool designed to predict the impact of anthropogenic sounds on marine mammals. The ESME Workbench (http://esme.bu.edu) allows the user to use site-specific environmental data such as bathymetry and sound-speed profiles to predict sound propagation in a wide range of scenarios and to record the sound exposures received by virtual animals. The acoustic propagation models use range-dependent depth profiles and depth dependent sound speed profiles to compute the received sound level for simulated animal from each simulated source. The propagation models use bottom and sea surface characteristics to account for losses that occur during reflection at these boundaries. Sound sources are specified through parameters such as source location, frequency, intensity, and beam pattern. The animal behavior is simulated using the 3 MB animal movement model. We will provide hands-on demonstrations at the meeting for those interested in learning more about the ESME Workbench. [Funded by ONR.]
Prediction of noise of moored ships
Authors: Di Bella Antonino , Remigi Francesca
Published: May 2013

The European Directive 2002/49/CE suggests to map noise in harbor areas with methods mainly used for industrial noise, in accordance with ISO standards. Nevertheless, in many cases, these methods do not seem suitable to describe the effects of noise due to moored cruise ships. For noise measurements of ships, it is possible to refer to ISO 2922 standard, but it results ineffective for the estimation of noise levels at distances bigger than 25 m from the sound source and to obtain reliable information about sound power level of big vessels. The aim of this study, performed by the University of Padova on behalf of Venice Port Authority, is to improve a procedure for predicting noise of moored ships in the harbor area by the means of measures and reverse analysis with numerical models.
Size effect of complexed plasmid DNA to gene transfection efficiency of microbubble-mediated sonoporation
Authors: Matsumoto Yoichiro , Zhang Yiwei , Azuma Takashi , Yoshinaka Kiyoshi , Osada Kensuke , Kataoka Kazunori , Takagi Shu
Published: May 2013

Ultrasound-mediated gene transfection in the presence of microbubbles is a recently developed promising nonviral gene delivery method. Detailed dynamics of pore opening on the cell surface has not been clarified. Especially, the pore size is one of the most essential parameters. In this study, we investigated the size effect of the complexed plasmid DNA (pDNA) on the transfection efficiency by packaging within the polyplex micelles. Both naked pDNA and complexed pDNA were transfected into cultured NIH3T3 cells using ultrasound in the presence of microbubble contrast agent, Sonazoid. The both size of the hydrodynamic diameter of naked and complexed pDNA estimated by a dynamic light scattering measurement were 600 and 120 nm, respectively. The transfection rates of the complexed pDNA evaluated by counting the number of cells that exhibited green fluorescent was 1.67%, while that of the naked pDNA was 0.92%. This efficiency enhancement depending on the size reduction showed that the pore sizes were distributed in the range of pDNA diameters. Since complexation changes the structure of pDNA in size and stability, more detailed study will be discussed in the presentation.