bluuebunny/crossref_metadata_2025 huggingface dataset:
The ‘‘Concerto for Conductor:’’ A new musical form
Authors: Nakra Teresa Marrin
Published: October 2013

In May of 2001, at Boston’s Symphony Hall, conductor Gil Rose walked out onto an empty stage with a coil of wire trailing from the back of his jacket. As he raised his hands in a starting gesture, the first chords of the Grieg Piano Concerto rang out. Subsequent gestures finished the initial flourish of the Grieg, and after several more bars of sampled orchestral and environmental music, orchestral musicians started slowly filtering onto the stage. The rest of the performance featured some very fun and energetic music making, reflecting both a sense of humor and a sense of inventiveness with a completely new form. This was the premiere performance of the world’s first ‘‘Concerto for Conductor.’’ The new musical form was the brainchild of this author, who wanted to develop a way to combine the ‘‘Conductor’s Jacket’’ sensor interface with live musicians on-stage. Composer John Oswald, whose imaginative setting was highly praised by the Boston press, was chosen and commissioned because of his reputation for inventive use of sampled sound. Aspects of his composition, the electronic systems behind it, and the possibilities for future Conductor Concertos will be discussed in the public presentation of this paper.
New performance techniques using Max/MSP and Csound
Authors: Lowe Arran
Published: October 2013

New musical developments have often come about with the discovery or invention of new techniques. Software programming in the Max environment and the language of Csound can allow one to develop new techniques for real-time performance. Using the computer as a compositional tool, sound design device, signal processing source, and performer, one is able to accomplish musical goals that were not possible due to the limitations of human performance with previous tools. Combining live human performers and dynamically controllable software synthesis, it is possible to attain a synergy of very familiar and very new ideas. This lecture and performance demonstration will feature some of the new musical possibilities that have resulted from undergraduate research and a dissertation in software synthesis.
The integration of computer-generated sounds and acoustic sources during live electro-acoustic improvisation
Authors: Cluett Seth A. , Smallwood Scott
Published: October 2013

A performance duo specializing in live electro-acoustic improvisation sought to create a balanced orchestration between live sound sources and computer generated sound. The sound sources were a Trinidadian steel-pan and four sheets of lead plate glass. The improvisation was limited to controlled, disciplined movements whose minimal nature exploited the natural acoustic properties of the sound sources. The sounds of the steel-pan and the glass were analyzed and algorithms were written that extracted acoustic information from the live sound. The analyzed sounds were then processed and re-introduced into the improvisation with dynamic control of the amplitude, parameters for, and amount of processing. Spatialization and integration of the acoustic and computer-generated sounds was considered and a multi-channel speaker system was used to introduce both into the performance space. This performance was undertaken for the 2001 International Computer Music Conference, in Havana, Cuba.
A practical side of M. C. Junger
Authors: Kleinschmidt Klaus
Published: October 2013

This is a chapter in the life of a man whose mind is in part filled with a mist of symbols and equations but which has another part that can create very practical applications of theoretical acoustics. I am fortunate enough to have shared for many years in Miguel’s prodigious intellectual output as well as his kindness and generosity. I will summarize the story of how he invented a product, basically made of dirt, about 50 years ago and of his participation in creating a unique and commercially successful acoustical material called SOUNDBLOX.
A new model for an underwater explosion bubble
Authors: Geers Thomas L. , Hunter Kendall S.
Published: October 2013

A new model for a moderately deep underwater explosion bubble is developed that integrates the shockwave and oscillation phases of the motion. A hyperacoustic relationship is formulated that relates bubble volume-acceleration to far-field pressure profile during the shockwave phase, thereby providing initial conditions for the subsequent oscillation phase. For the latter, new equations are derived that include wave effects in both the external liquid and the internal gas. The equations are then specialized to the case of a spherical bubble, and bubble–surface displacement histories are calculated for dilational and translational motion. Agreement between these histories and experimental data is found to be good. [Research sponsored by the DTRA and ONR.]
Miguel C. Junger, an inspirational mentor in structural acoustics
Authors: Feit David
Published: October 2013

When Lord Rayleigh wrote his book, The Theory of Sound in the 19th century, he treated vibrations of structures and sound radiation in two separate volumes. In the last half of the 20th century, the field of structural acoustics, i.e., the theory of acoustic radiation and scattering from elastic structures, was developed in response to Navy needs. Miguel C. Junger is one of the seminal contributors to this field of structural acoustics, and has been the inspirational mentor to myself and others associated with him at Cambridge Acoustical Associates. This presentation discusses how this mentoring proceeded, the resulting research derived from this, and the circumstances leading to our book Sound, Structures and their Interaction originally published by MIT Press, and now published by the Acoustical Society of America.
Sound and structural destruction
Authors: Barger James E.
Published: October 2013

Our honoree is well known for his, and David Feit’s, book on the interaction of sound with structures. In this work, equations representing both sound and structure are linearized. Results apply to most cases, even when sound pressures exceed safe hearing levels. But there are occasions when it is wanted to destroy the functionality of a structure by a directed shock wave in its surrounding fluid. This type of interaction exceeds yield stress in the structure, causing permanent deformation. This paper describes both an explosive and a nonexplosive underwater shock generation device and shock propagation to a 0.8 m diam metal sphere. The damage is computed by finite element methods, and compared to actual damage. Insights are found from the linear analysis.
Inexpensive laboratory experiments for nonscience students
Authors: Hansen Uwe J.
Published: October 2013

Students who experience acoustics rather than merely being exposed to concepts universally gain insights not otherwise available. The experience of doing rather than simply hearing greatly enhances the excitement associated with learning. With that understanding, it seems almost imperative to include a laboratory component in every acoustics course. Frequently cost precludes the use of sophisticated equipment in multiple sets of identical experiments, however, sequential use of different laboratory setups provides a simple solution to that problem. Furthermore, there are many simple devices which lend themselves to quantitative measurements, and there is available relatively low-cost computer software for rather sophisticated experiments. Among experiments to be discussed and illustrated are graphic wave addition, complex wave synthesis using a polyphonic keyboard and a computer based digital oscilloscope, standing transverse waves on a spring, standing longitudinal waves in an air column, spectral analysis using inexpensive computer software with a sound card in a PC, normal mode mapping with Chladni patterns and phase shift observation in Lissajou figures, and sound pressure level measurements.
Determining the temperature dependence of Young’s modulus using a tuning fork
Authors: Blodgett Earl D.
Published: October 2013

We describe a simple experiment that illustrates the use of acoustic resonance to determine the temperature dependence of an elastic constant. Instead of a traditional crystal that has been carefully cut and polished to provide a high Q, the specimen is an ordinary tuning fork. The resonant frequency of a tuning fork changes with temperature because of changes in Young’s modulus [D. W. Schindel et al., J. Acoust. Soc. Am. 102, 1296–1308 (1997)]. In the stainless steel fork used in a previous undergraduate research study [L. Bates et al., J. Undergrad. Res. Phys. 18, 9–13 (1999)], the resonant frequency decreased by 0.01854 Hz for each 1°C increase in temperature. That experiment was carried out over a range of temperature from 25°C to 80°C using a simple oven. As the frequency change is not very dramatic, it is very important to have either a method of very precisely measuring the resonant frequency or one must extend the temperature range to get a sufficiently large total shift in frequency. We describe several options for tracking the resonant frequency.
Overview of predicting community noise from industrial facilities using ray-tracing software
Authors: Brittain Frank H.
Published: October 2013

Predicting community noise from industrial facilities is vital to both assessing the environmental impact and designing plants to meet community noise limits. Predicting noise levels with sufficient accuracy requires a thorough understanding of not only the software package used, but also the whole process. Just knowing how to input data to the software is never sufficient. Atmospheric effects, noise sources, the modeling process, and the assumptions built into the software must also be clearly understood. Until recently, community noise predictions have most commonly been made using a spreadsheet. This is convenient and simple, but it is difficult to adequately include many effects, such as screening and reflection of noise by both barriers and other equipment. Commercially available ray-tracing software allows more precise predictions of community noise, including screening and reflections. However, the accuracy of predictions depends primarily on the quality of the input to the software. As a start to the process of developing the understanding needed, this paper reviews the basic approach used for all community noise predictions, alternative prediction methodologies, capabilities of typical software packages, and the technology typically built into ray-tracing software. Developing models, and some of the problems often encountered are also identified and reviewed.
Industrial noise and noise maps for cities—An application of ray tracing techniques
Authors: Probst Wolfgang
Published: October 2013

It is shown how extended sources like radiating openings or surfaces, large area sources or extended line sources can be modeled for prediction purposes even if pure geometric models based on ray tracing are used. The limit of ray tracing technology comes into play where wavelengths and the dimension of reflecting or radiating objects are similar. Examples are presented using conical beam method and projection method. Diffraction is described by a barrier attenuation of the direct ray that is frequency dependent and that is based on the well known and experimentally adapted Maekawa formulas. If many arbitrary oriented diffracting and reflecting objects are crossed by the ray it may be necessary to add the contribution of more possible paths. Ray tracing models have their limitations like all other models used for noise prediction. On the other side it is not feasible to solve the wave equation using the environment as it exists in large and complex models. With this contribution some of these limitations are outlined and it is shown that these models can be used effectively for the prediction of noise levels in the vicinity of industrial sites.
Elements of accuracy/inaccuracy in outdoor sound level predictions using ray-tracing models
Authors: Putnam Robert
Published: October 2013

Sound emissions play a vital and often pivotal role in a broad range of issues in the design of modern power generating facilities. The modeling of those sound emissions must be as accurate as possible in order to minimize the cost of noise control measures. This paper presents an overview of the principal components of the expected accuracy in modeling the sound emissions of sources to far field outdoor positions, including source data bounds. The relative magnitudes of the various elements of this accuracy will be discussed, and an assessment of practical expectations of achievable accuracy will be included. A comparison will be presented of preliminary results of a round robin survey involving several different computer models and a proposal will be offered for additional round robin testing.
Measured and predicted acoustic attenuation in binary gas mixtures
Authors: Ejakov Sally G. , Phillips Scott , Dain Yefim , Lueptow Richard M. , Visser Jacobus H.
Published: October 2013

Acoustic attenuation in a gas mixture results from the combined effects of molecular relaxation and the classical mechanisms of viscosity and heat conduction. Acoustic attenuation was measured in methane–nitrogen mixtures for a wide range of concentrations in a large vessel using a pulsed technique. The signals from four pairs of transducers, each operating at a different frequency, were measured as a function of the distance between the transducers. The pressure in the vessel was varied to cover a wide range of f/p. A correction for diffraction for each transducer pair was applied to the data resulting in overlap between the data from different transducers at the same f/p. The pure methane measurements are in good agreement with published results. Measurements for mixtures of methane and nitrogen agree well with calculations that include both relaxational and classical attenuation [J. Acoust. Soc. Am. 109, 1955 (2001)]. Similar measurements were completed for mixtures of carbon dioxide and nitrogen. Calculations to predict the attenuation for these mixtures are ongoing. [This work was funded in part by the State of Oklahoma.]
Backscattering of acoustic waves in a cavity with random variations in area and sound speed
Authors: Beran Mark J. , Frankenthal Shimshon
Published: October 2013

The transmission of an acoustic signal in a cavity with random variations in area and sound speed is discussed. We first review the case of a single propagating mode and study the statistical properties of the forward and backward propagating waves in a cavity with only random sound-speed fluctuations. It is then shown that adding the effect of random variations in cavity area does not change the form of the basic statistical equations and previously obtained solutions may be used. The only change is in the characteristic length scale of the solution. We next consider the case of two propagating modes when the intermodal coupling is small. It is shown how the statistical hierarchy obtained in the single mode case may be used to obtain the effects of mode interaction.
The complex phase gradient method: A new tool for the investigation of immersed elastic plate angular resonances
Authors: Lenoir Olivier , Conoir Jean-Marc , Izbicki Jean-Louis
Published: October 2013

The Phase Gradient Method applied to the complete characterization of the angular resonances of an immersed elastic plate, i.e., the angular poles of the plate reflection coefficient, was proven to be efficient, as far as the pole imaginary parts are not too large when compared to their real parts. This method consists of plotting the reflection coefficient phase partial derivative with respect to the sine of the incidence angle, considered as real, vs incidence angle. At the vicinity of an angular resonance, the plot exhibits a Breit–Wigner shape, whose minimum is located at the pole real part and whose amplitude is the inverse of its imaginary part. However, when the imaginary part is too large, this method does not give its value with a sufficient accuracy, compared to the exact calculation of the root in the complex angle plane. An improvement consists in plotting in 3D, in the complex angle plane, the angular phase derivative with respect to the real part of the sine of the incidence angle, considered as complex. When an angular pole is reached, the 3D curve shows a clear cut transition of very large amplitude, whose position is easily obtained.
Introduction of frequency, angular, longitudinal, and transverse quality factors to characterize the resonances of a water-loaded elastic plate
Authors: Lenoir Olivier , Conoir Jean-Marc , Izbicki Jean-Louis
Published: October 2013

The frequency derivative of the phase of the immersed elastic plate reflection coefficient is related to its derivatives with respect to the longitudinal and transverse phase velocities in the plate and to the phase velocity in the surrounding fluid. In this relation, products, composed of one of these variables and of the corresponding phase partial derivative, appear. At a resonance frequency, the frequency phase derivative amplitude corresponds to the inverse of the resonance half-width; the frequency-frequency phase derivative product can be identified to a frequency quality factor, denoted as Qx. By analogy, all the other products correspond to quality factors. It is shown that the product assigned to the fluid phase velocity corresponds to an angular quality factor, denoted as Qy. The products assigned to the longitudinal and tranverse phase velocities are naturally qualified as longitudinal and transverse quality factors, denoted as Ql and Qt. It is established that the sum of Qx and Qy equates the sum of Ql and Qt. Moreover, each of these quality factors is shown to be related to a stored kinetic energy, associated either to a normal displacement, to a parallel displacement, to a longitudinal or to transverse displacement.
Directions with negative Poisson’s ratio in crystals
Authors: Tokmakova Svetlana
Published: October 2013

Materials with negative Poisson’s ratio are peculiar in that they expand laterally when stretched. The Poisson’s ratio is the ratio of lateral strain in the direction n to the longitudinal strain during the stretching of a cylindrical rod along rod axis m. In the paper the stereographic projections of Poisson’s ratio for a set of acoustic crystals, metals, alloys, binary compounds, and for the elements of periodic system were computed. From these stereographic projections the cuts with extreme values of Poisson’s ratio were determined. Elastic modules of crystals from the manual [Landolt-Bornstein, Numerical Data and Functional Relationships in Science and Technology, New Series, Group III, Vol.18, Berlin (1984)] were applied in calculations. Our evaluations have shown that for most fcc crystals the Poisson’s ratio receives negative values for directions of a stretch vector m located inside a cone with an axis [110], relevant to the Euler angles (45,0,90). The parameters of cone were spotted for a set of crystals. For beta cristobalite SiO2 a decrease of rod cross-section under the uniaxial compression was revealed for the directions of vector m oblique to [111]. Elastic modules of SiO2 have been taken from Kimizuka et al., Phys. Rev. Lett. 84, 5548–5551 (2000)]. Some possible applications of materials with a negative Poisson’s ratio basing on their unusual acoustic properties are discussed. For the elements of periodic system the results of calculations will also be submitted on the Web-site: www.akin.ru as the color table.
Speech prosody in cerebellar ataxia
Authors: Casper Maureen A. , Raphael Lawrence , Harris Katherine S.
Published: October 2013

Ataxic dysarthria has been investigated both acoustically and perceptually without correlation to neurological imaging. The present study sought an acoustic signature with correlation to neurological degeneration for the speech disturbance recognized in cerebellar degeneration. Acoustic measures and magnetic resonance imaging were used to measure speech disturbance in ataxic speakers. The spatial-temporal properties of syllable production in ataxic and normal speakers were examined in twelve speakers (six ataxics and six normals). The speaking task was designed to elicit six different prosodic conditions and four contrastive prosodic events. The normal speakers showed statistically significant differences for all four prosodic contrasts. The cerebellar speakers showed a different pattern of lengthening and syllable reduction from the normal speakers. These differences were found in both syllable duration and F1. An estimate of speech deterioration as determined by individual differences between cerebellar and normal subjects’ acoustic values of the four prosodic contrasts was then used in correlation analyses with MRI ratings. Moderate correlations between speech deterioration and cerebellar atrophy were found in the measures of syllable duration and f0. A strong negative correlation was found for F1. The normal model described by the prosodic contrasts provided a sensitive index of cerebellar pathology with quantitative acoustic analyses.
Training a vowel contrast using visual articulatory feedback
Authors: McGowan Richard S. , Ferrier Linda , Chenausky Karen , MacAuslan Joel
Published: October 2013

The /i/–/I/ distinction can be difficult to make in speech for deaf, dysarthric, and many non-native English speakers. A computer program was designed that prompted speakers, with orthograpraphy, to produce a simple single syllable word containing either vowel and recorded the speakers response. The program provided feedback in one of two forms: either auditory (AF) or auditory and visual articulatory feedback (VAF). The auditory feedback was the actual and correct pronunciation of the word. VAF provided schematic representations of where the tongue was according the speaker’s actual production of the vowel in relation to where it would be placed for the best production of the target vowel. Articulatory representations were inferred automatically based on the measured formant frequencies of the speaker’s production. Four subjects who were particularly poor at making the vowel distinction were recruited to test VAF in a single subject case study design. After baseline scores for the vowel distinction were established in four sessions, each subject was given training using each of AF and VAF, with no words the same for each of the types of training. There was more improvement in the vowel distinction for the auditory and visual feedback compared to the auditory feedback alone.
The relationship between auditory temporal resolution and auditory object formation
Authors: Dunn Camille C. , Carrell Thomas D.
Published: October 2013

The goal of the present experiment was to determine whether a relationship exists between auditory temporal resolution and the ability to use amplitude modulation for auditory object formation in sentence perception. A standard gap detection task was used to evaluate temporal resolution in listeners [D. P. Phillips, T. L. Taylor, S. E. Hall, M. M. Carr, and J. E. Mossop, J. Acoust. Soc. Am. 101, 3694–3705 (1997)]. Each stimulus consisted of a leading element, a silent duration, and a trailing element. Both within- and between-channel detection was measured. An adaptive tracking procedure (PEST) was used to determine the 70%-correct gap durations for each subject. Next, a sentence identification task was used to evaluate listeners’ abilities to use amplitude modulation to extract speech from noise. Time Varying Sinusoidal (TVS) sentences were created for this purpose [T. D. Carrell and J. M. Opie, Percept. Psychophys. 52, 437–445 (1992)]. Half of the TVS sentences were amplitude modulated at 100 Hz and half remained unmodulated. The difference in intelligibility between the modulated and unmodulated sentences was used as a measure of auditory object formation. No correlation was found between gap discriminability and auditory object improvement among the subjects we tested. A wider range of subjects is currently being investigated.
Experimental confirmation of time reverse operator eigenvalues on target scattering moments
Authors: Meyer Alan W. , Chambers D. H.
Published: October 2013

Laboratory experiments confirm multiple distinct, scatterer dependent, eigenvalues of the time reverse operator (TRO) for a linear time reverse mirror (TRM). Prada and Fink [Wave Motion 20, 151–163 (1994)] discuss a one-to-one correspondence between the eigenvalues of the TRO and each scatterer. Chambers and Gautesen [J. Acoust. Soc. Am. 109, 2616–2624 (2001)] extend this theory to equate the TRO eigenstates to functions of the induced scattering moments of the target object. Each scatterer has a monopole moment associated with the compressibility contrast between the object and the surrounding medium. Likewise, a density contrast will induce multiple dipole moments. Each of these moments results in an eigenstate of the TRO. Experimentally the TRO was determined for two cylindrical scatters in two different media: glass and aluminum. Procedurally, in each case the eigenstates for the TRO were first determined. The DORT method was then applied and the focal point determined. An association between the scattering moment and an eigenstate is confirmed when more than one eigenstate focused the TRM to the same scatter. [This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under Contract No. W-7405-ENG—48.]
Spatial and frequency selectivity of a matched filter array in a conference room
Authors: Grove Deborah M. , French Joseph C.
Published: October 2013

Matched filter array (MFA) processing uses impulse responses (IRs) in its algorithm to provide high signal-to-noise and 3-D spatial selectivity. The spatial and frequency selectivity of the MFA is shown for an array of eight randomly placed microphones in a 0.7-s reverberant conference room. The IRs were measured using nine averages of a 16383 sample maximum length sequence at a 16-kHz sample rate from a loudspeaker representing on- and off-focus conditions. The MFA response was formed offline by convolution of the time-reversed IR with an IR representing the incoming source position to each microphone, with a final summation over the array. Truncation of the impulse responses is applied to remove anticausal echo. The spatial selectivity of this array is on the order of 25 cm from the focus. The influence of the room transfer function on the frequency response of the MFA is shown. It is seen that the frequency focal volume immediately degrades off-focus for the high frequencies first and that the off-focus condition causes a time-delay in the array response. The influence of individual matched filters versus the array response on the spatial selectivity is explained. [Work supported by Intel and Texas Instruments.]
Transmission mode acoustic time reversal imaging with application to geophysical vertical seismic profiling
Authors: Lehman Sean K. , Devaney Anthony J.
Published: October 2013

We develop the theory of transmission mode time reversal imaging for arbitrary transducer geometry. Although it is not possible to implement such a system in practice, we prove that transmission mode time reversal imaging is achievable a posteriori from the scattered field time series as measured at the receivers. The theory is developed for any arbitrary geometry in which the transmitters and receivers are not colocated. We provide simulated proof-of-principle and finite-difference time-domain (FDTD) examples designed to model the case of geophysical vertical seismic profiling in which a series of sources are excited on the surface and the scattered fields are measured on a chain of receivers in a bore hole.
Laboratory experiments of time reversed acoustics applied to sonar in shallow water waveguides
Authors: Shipley Mitchell N. , Stokely John , Smith Kevin B. , Larraza Andres
Published: October 2013

Active sonar research at the Naval Postgraduate School Advanced Acoustic Research Laboratory (AARL) has focused on real time adaptation of the active sonar transmit signal. Recent work with Time Reversal Acoustics (TRA) has demonstrated the ability of this approach to adapt in real time to complex environments with little knowledge of the environmental parameters. The present work applies TRA techniques to shallow water active sonar to improve target echo SNR. The approach is to conduct scaled laboratory tank experiments of the TRA sonar and compare results to standard matched filter active sonar processing techniques. Results of laboratory TRA sonar experiments will be presented, to include the high SNR case, the effects of increasing noise levels, and the TRA sonar approach as applied to an active barrier concept.
Decision-directed passive phase conjugation: A robust and simple architecture for array receivers in the underwater communications channel
Authors: Flynn John A. , Ritcey James A. , Fox Warren L. J.
Published: October 2013

A decision-directed extension to the passive phase conjugation (PPC) technique of array demodulation for underwater communications channels is presented. The PPC method utilizes a probe signal from the transmitter to exploit the time-reversal concept in a one-way fashion at the receiver on subsequent unknown data signals [D. R. Jackson et al., Conf. Rec. 34th Asilomar Conf. on Signals, Syst., and Comp., Vol. 1, 680–683 (2000)]. PPC demonstrated excellent equalization of communication bursts in shallow water with sparse array reception. The decision-directed extension to PPC presented here virtually eliminates the need for repeated channel probing, while improving channel estimation in rapidly varying, noisy environments. The technique utilizes decision-directed channel modeling in a fixed-window linear statistical framework, a deterministic least squares optimization criteria, and robust conjugate-gradient numerical methods driving the PPC demodulator. The resulting architecture scales linearly with the number of sensors, has a per-sensor complexity competing with fast-RLS algorithms, and avoids performance limitations of both LMS and E-RLS. Three difficult shallow water demonstrations at 1–5 km show robust channel tracking with good BER and excellent equalization performance. [Work supported by ONR.]
Marine Mammal Protection Act (MMPA), Endangered Species Act (ESA), and regulations for Scientific Research Permits
Authors: Nitta Gene , Terbush Ann
Published: October 2013

The MMPA, ESA, and Fur Seal Act, mandate the protection and conservation of marine mammals and other protected species, and prohibit the taking, importation, and export of protected species. Exceptions for scientific research, enhancement, public display, and commercial and educational photography, are allowed under special exception permits or other appropriate authorizations issued under Section 10 of the ESA and Section 104 of the MMPA. Permit issuance must also meet NEPA, ESA Section 7, CITES, and where necessary, CZMA requirements. NOAA Fisheries develops and implements policies and regulations for issuance of permits and authorizations to take marine mammals for the activities noted above, and organizes and executes the national program for tracking captive marine mammals. Marine mammal permits are coordinated with NOAA Regional Offices, the Marine Mammal Commission, the Fish and Wildlife Service, and the Animal and Plant Health Inspection Service. Input on permit applications is received from other Federal, State, and local agencies, the academic community, public display institutions, nongovernmental organizations, and the general public. NOAA fisheries coordinates national policy for minimizing harassment from human recreational activities directed at marine mammals and conducts outreach to the public about the permit program and responsible wildlife viewing practices.
Regulating underwater sound in Eastern Canada: An operational perspective from the Department of Fisheries and Oceans
Authors: Macnab Paul A.
Published: October 2013

Fisheries and Oceans in Canada are responsible for policies and programs that support economic, ecological and scientific interests in Canada’s marine waters. Central to the Department’s mandate is the conservation of living marine resources, including mammals. Canadian regulations, permits and approval processes will be discussed with an emphasis on acoustic devices and related noise issues on the Scotian Shelf. Commercial seismic research on the Shelf has added considerably to the sound dependent marine research typically undertaken by government and naval scientists. This increase in noise has prompted calls for cumulative environmental assessments that address additive and synergistic effects. Existing mitigation measures include sensitive area avoidance and coordination to avoid spatial and temporal overlap. Operations are restricted near the Sable Gully, a large canyon recognized as the most significant cetacean habitat on the Scotian Shelf. Evolving nonregulatory approaches include codes of conduct, precautionary buffer zones and voluntary compliance with operational guidelines. Work conducted by Defence Research Establishment Atlantic on historical levels of ambient noise has been especially instructive in these matters. Additional measurement and modeling expertise is needed to help establish safe operating distances and environmental quality standards that could be applied to all anthropogenic sound sources near the Sable Gully.
Sound insulation performance in shipboard
Authors: Kang Hyun-Ju , Kim Sang-Ryul , Kim Jae-Seung
Published: October 2013

This work deals with correlation between the field sound transmission loss (FSTL) in cabins and the sound transmission loss (STL) in reverberation chambers. To this end, experimental investigations are carried out on various ships such as a passenger, a plant ship, and a container ship. Comparisons of FSTLs and STLs indicate that a passenger ship shows the best performance in sound insulation over the other ships, with equal or greater than STL. This is because the factory made unit cabins in the passenger ship are free from sound leakage, while the common partitions between cabins in other ships cannot be free from flanking transmissions. It is found that FSTL can be degraded up to 15 dB in comparison with STL, mainly because of sound leaks. Numerical predictions are carried out in order to identify each sound leak between structural members such as wall and ceiling. Agreement between experiments and predictions is reasonably good with the discrepancy up to 3 dB in general, which validates the proposed scheme for evaluating FSTL.
The acoustic design for theaters on cruise ships: The differences between land and sea
Authors: Cooper Russell
Published: October 2013

Theater design for cruise ships presents many challenges that are different than building designs on land. The acoustic challenges include a limited palette of material choices based on weight, space, and fire restrictions, room adjacency issues, and coordination with shipyard construction methods. We will discuss the program uses of the spaces and the acoustic criteria, architectural treatments, room shaping and volume, sound isolation utilizing sandwich and floating floor constructions, and HVAC noise control without the use of fiberglass. We will specifically focus on the design for Royal Caribbean Cruise Lines Voyager, Millennium, and Radiance class ships. Information will be presented that could be transferable to land based designs to solve acoustic problems that involve similar weight, space, and fire restrictions.
Shipboard noise prediction algorithms
Authors: Fischer Raymond W.
Published: October 2013

For new ship designs to have acceptable noise environments, it is imperative that effective acoustical prediction tools be used. Accurate prediction tools can be used to optimize the selection of treatments and aid in trade-off studies. In this manner the typical adverse impact of noise control treatments on space, weight, cost, and operation of the vessel can be minimized. This paper describes the algorithms used in a hybrid Statistical Energy Analysis (SEA) airborne noise prediction program specifically geared for marine applications. The program combines the elements of architectural acoustic, energy analysis and empirical data collected over many ship projects. It accounts for the unique features involved with marine structures and is applicable to most types of large and small vessels mono-hulls, catamarans, surface effect ships (SESs) or Small Water Area Twin Hulls (SWATHs). Not only does the program predict the noise levels it can be used to determine the primary transmission paths, vibration levels, and radiation efficiency of any structural component, and composite panel transmission loss. The program has been employed with great success on over a dozen projects. Comparison of predicted and measured noise levels will be presented.
Interpreting research results: Government regulation of anthropogenic noise sources
Authors: Rose Naomi A.
Published: October 2013

The Precautionary Principle, which advocates taking anticipatory management action in the absence of complete proof of harm, is embedded in several U.S. environmental laws, including the Marine Mammal Protection Act and the Endangered Species Act. However, in practice it is often ignored. Recent U.S. regulatory actions addressing the following anthropogenic noise sources are evaluated as cases in point: the North Pacific Acoustic Laboratory (NPAL), the U.S.S. Winston S. Churchill ship shock trials, and the Surveillance Towed Array Sensor System (SURTASS) Low Frequency Active (LFA) sonar. The impact of anthropogenic noise on marine mammals is poorly understood. Therefore, establishing adequate mitigation measures for noise sources is difficult. In an effort to increase knowledge and build toward certainty regarding the impacts of anthropogenic noise on the marine environment, recent research on low-frequency noise has focused on behavioral responses of large whales. These studies address limited hypotheses, but their results have been broadly interpreted to justify regulatory decisions. The pursuit of carefully designed research on the impacts of noise on the marine environment and the refinement of noise source mitigation is important, but interpreting research results is subject to political and economic pressures, casting doubt on the research conservation value.
A journalist’s perspective on noise and marine mammals
Authors: Russell Dick
Published: October 2013

In the course of several years researching and writing Eye of the Whale (Simon & Schuster, 2001, 688 pages), the author interviewed a number of marine scientists about this subject and described at some length scientific findings over the past several decades. These pertained to California gray whales, their vocalizations, and the impact of various acoustical ‘‘playbacks’’ upon this species at different locations. In particular, the author described studies of Navy LFA sonar in California and of seismic oil exploration off Russia’s Sakhalin Island. Scientific opinion appeared divided over whether LFA sonar, especially, would pose a substantial threat to marine mammals. However, as regarding both LFA sonar and seismic testing, gray whales were observed to avoid certain regions they would otherwise normally inhabit. Subsequent interviews have confirmed the possibility of a severe threat to marine mammal habitat. During this process, much has also been learned about the ways and means to improve communication between journalists and scientists.
Environmentally robust nulling applied to rank-N stochastic matched field processing
Authors: Daly Peter M. , Baggeroer Arthur B.
Published: October 2013

Passive source localization in shallow water is complicated by both the uncertain propagation environment and the presence of strong interferers. Traditional spatial nulling techniques fail to accommodate environmental variability, while principle component methods neglect energy that has spread beyond a rank-1 signal characterization. One can accommodate environmental variability by treating the parameters of a propagation environment as random quantities. This yields a random acoustic pressure field at a receiver, which can be approximated by a Gaussian random vector, represented by a spatial covariance matrix. To mitigate these nulling problems, one can characterize the interfering signal in this manner. With such a model, a whitening filter can be calculated and applied to the received signal. This provides a spatial null that removes the multiple-component energy contributed by the interferer in an uncertain propagation environment. Rank-N localization techniques can then be applied, robustly estimating a target source location in the presence of environmental uncertainty. [Work supported by the DARPA Advanced Technology Office.]
Quantitative ambiguity analysis for matched-field parameter estimation
Authors: Xu Wen , Baggeroer Arthur B.
Published: October 2013

Matched-field methods concern the estimation of source location and/or ocean environmental parameters by matching the measured signal field with the modeled signal field. The resulted ambiguity output is often characterized by a multimodal structure since the typical signal field is a highly nonlinear function of the embedded parameters. In the high signal-to-noise ratio (SNR) region, the peak of the true parameter protrudes prominently above the noise and can be located accurately; below some SNR, the true peak often falls below the noise level and is obscured by other ambiguous peaks, leading to a larger estimation error and the well-known threshold phenomenon. Therefore, issues on the output ambiguity structure are very important for the development of any matched-field algorithm operated in low SNR scenarios (e.g., passive source localization). To understand some fundamental ambiguity behaviors, a quantitative approach for error analysis is developed in the context of the maximum likelihood estimate. The derived probabilistic error at each scanning parameter point is determined by the signal ambiguity level, the distance to the true parameter point, and the SNR. Accordingly, the threshold SNR can be located by comparing the relative size of the main lobe and side lobe error contributions.
A test of autonomous matched-field tracking with a sparse seafloor array
Authors: Stevenson J. Mark , Bucker Homer , Briest Susan G. , Klausen Mike , McDonald Vincent K.
Published: October 2013

A recent experiment demonstrated the feasibility of using input from a sparse seafloor array of hydrophones [Stevenson and Bucker, J. Acoust. Soc. Am. 108, 2645 (2000)] into a matched-field tracking algorithm [Bucker, J. Acoust. Soc. Am. 96, 3809–3811 (1994)] to return tracks of submerged sound sources. In previous work, the algorithm was tested using recorded data. This paper describes a near real-time implementation of this processing. The tracking algorithm operates in near real-time in a DSP (digital signal processor) running autonomously inside the unit. The procedure is to select N Fourier frequency bins based on S/N ratios after CFAR normalization, and then to determine the best tracks using M-of-N processing. Observations over 3–6 min tracks are matched against the calculated sound field stored in a look-up table [Bucker and Baxley, J. Acoust. Soc. Am. 106, 3226–3230 (1999)]. We compare near real-time results obtained autonomously with those obtained in post-experiment analysis. [Work supported by ONR, Code 321-SS.]
Shallow water localization of targets in range rate by use of sequential importance sampling
Authors: Kraut Shawn , Krolik Jeffrey
Published: October 2013

We examine the problem of localization of targets in shallow water environments. In contrast to standard matched field processing (MFP) approaches, we propose a method based on range-rate, rather than range. We call this approach moving target range-rate estimation (MOTRE). It is more robust with respect to environmental uncertainty. This is because range-rate localization depends on the product of the horizontal wave numbers of the channel modes times the differential distance the target travels in a sampling interval, rather than the baseline distance to the sensor array. Our technique assumes some knowledge of target dynamics (constant velocity) and the physics of the channel modes to hypothesize candidate sequences of mode coefficients. A likelihood surface in range-rate and depth is computed using a nonlinear state-space model, related to a Kalman filter, to constrain the evolution of the unknown mode coefficients. We update the likelihood as new data is received by using a method of sequential importance sampling (SIS), a topic of interest in recent statistics literature. Our results indicate that MOTRE outperforms conventional MFP in its ability to produce easily identifiable, unambiguous peaks in the likelihood surface, using a vertical line array in a shallow-water channel.
The effect of wall angles near a speech source on hearing comfort
Authors: Stefaniw Abigail , Shimizu Yasushi
Published: October 2013

This study will involve a controlled experiment to determine the correlation between hearing comfort and lateral energy fraction (LEF). (Hearing comfort has also been described as ease of hearing, and is a measure of speech intelligibility.) LEF is dependent on the geometry of surfaces near the source. Therefore, in order to study the effect of the angle of reflective walls near a speech source on hearing comfort, rooms with identical reverberation time, noise level, and volume are modeled. The angle between walls near the speaker is the only physical variable. The RT in every room will be 0.6 s and the background noise will be exactly NC 25. The angle between reflective walls on either side of the speaker will be changed in 5° increments. The speaker is always located 3 ft. in front of the varying corner, and the listener is always located 15 ft. from source. This ensures that the signal to noise ratio can also be held constant. The data from this modeling experiment should explain the relationship between hearing comfort and room geometry, as measured by the lateral energy fraction.
A completed study of the architectural repair of the acoustics in Koubek auditorium at the Catholic University of America
Authors: Ellis Donna A.
Published: October 2013

Koubek Auditorium is used for architecture classes and guest lectures in the School of Architecture and Planning at the Catholic University of America in Washington, DC. Inadequate acoustics in this space result in ineffective use of the space as well as a poor teaching environment. The main problem areas are excessive background levels and reverberation times. Using a 1/3-octave band, background levels range from 47.6 dB–56.5 dB, reverberation times range from 0.9–1.6 s, and the noise criteria (NC) is anywhere from NC40 to as high as NC60, depending on where one is seated. The intent of this paper is to discuss the analysis and implementation of the acoustical corrections, as well as the end result of the changes and how those results improve the learning environment in the space.
Speech listening difficulty and word intelligibility of aged listeners in reverberant sound fields
Authors: Sato Hiroshi , Sato Hayato , Yoshino Hiroshi , Morimoto Masayuki
Published: October 2013

The experiment was performed to present the effect of hearing loss on listening difficulty and word intelligibility with aged subjects in same sound fields of the previous work [M. Morimoto et al., J. Acoust. Soc. Am. 108, 2633 (2000)], and the result of this experiment is compared with this previous work. In the test, both the listening difficulty and the intelligibility were assessed using word lists based on word familiarity. The results demonstrate that (1) The relation between listening difficulties of young subjects and aged subjects is highly correlated. The range of scores of aged subjects is half of that of young subjects. (2) This word intelligibility score of young subjects is higher than that of aged subjects by 25% in all conditions. This result is the same as the previous work [H. Sato et al., J. Acoust. Soc. Am. 108, 2634 (2000)]. (3) The relation between listening difficulty and word intelligibility shows the same tendency for the both aged and young subjects. (4) Hearing level has a good correlation with listening difficulty and word intelligibility scores.