bluuebunny/crossref_metadata_2025 huggingface dataset:
Effective area of acoustic lure surveys for Mexican spotted owls (Strix occidentalis lucida)
Authors: Denes Samuel L. , Bowles Ann E. , Plotkin Kenneth , Hobbs Chris , Kern John , Pruitt Elizabeth
Published: October 2013

During acoustic lure surveys for birds, topography and ambient noise are likely to be important determinants of detectability. Examinations of propagation were conducted for acoustic lures (human-made calls) and owl responses recorded during acoustic surveys for Mexican spotted owls in the Gila National Forest (2005). Lure surveys were designed based on formal agency protocols, which assumed a 0.43-km detection range under typical conditions. A total of 558 points was called over a heavily forested, topographically complex 20×24-km area. Real-time measurements of owl calls and lures were made with a calibrated recording system. Ambient noise was collected using an array of 39 Larson-Davis 820 and 824 sound-level meters. The NMSIM (Wyle Laboratories) single-event propagation simulator was used to model propagation of both owl and human calls. The resulting model of survey effort was compared with a simple two-dimensional statistical model. Probability of detecting owls did not fit the expectations of the agency protocol, suggesting that acoustic propagation should be considered during owl surveys. [Work supported by U.S. Air Force ACC/CEVP; USFWS Permit No. TE024429]
Phase aberration correction for a linear array transducer using ultrasound radiation force and vibrometry optimization: Simulation study
Authors: Urban Matthew W. , Greenleaf James F.
Published: October 2013

Diagnostic ultrasound images suffer from degradation due to tissues with sound speed inhomogeneities causing phase shifts of propagating waves. These phase shifts defocus the ultrasound beam, reducing spatial resolution and image contrast in the resulting image. We describe a phase aberration correction method that uses dynamic ultrasound radiation force to harmonically excite a medium using amplitude-modulated continuous wave ultrasound created by summing two ultrasound frequencies at f0=3.0 MHz and f0+Δf=3.0005 MHz. The phase of each element of a linear array transducer is sequentially adjusted to maximize the radiation force and obtain optimal focus of the ultrasound beam. The optimization is performed by monitoring the harmonic amplitude of the scatterer velocity in the desired focal region using Doppler techniques. Simulation results show the ability to regain a 3.0-MHz focused field after applying a phase screen with an rms time delay of 95.4 ns. The radiation force magnitude increased by 22 dB and the resolution of the field was regained. Simulation results show that the focus of the beam can be qualitatively and quantitatively improved with this method. [This study was supported in part by Grants EB002640 and EB002167 from the NIH.]
A meta-analysis of acoustic correlates of timbre dimensions
Authors: McAdams Stephen , Giordano Bruno , Susini Patrick , Peeters Geoffroy , Rioux Vincent
Published: October 2013

A meta-analysis of ten published timbre spaces was conducted using multidimensional scaling analyses (CLASCAL) of dissimilarity ratings on recorded, resynthesized, or synthesized musical instrument tones. A set of signal descriptors derived from the tones was drawn from a large set developed at IRCAM, including parameters derived from the long-term amplitude spectrum (slope, centroid, spread, deviation, skewness, kurtosis), from the waveform and amplitude envelope (attack time, fluctuation, roughness), and from variations in the short-term amplitude spectrum (flux). Relations among all descriptors across the 128 sounds were used to determine families of related descriptors and to reduce the number of descriptors tested as predictors. Subsequently multiple correlations between descriptors and the positions of timbres along perceptual dimensions determined by the CLASCAL analyses were computed. The aim was (1) to select the subset of acoustic descriptors (or their linear combinations) that provided the most generalizable prediction of timbral relations and (2) to provide a signal-based model of timbral description for musical instrument tones. Four primary classes of descriptors emerge: spectral centroid, spectral spread, spectral deviation, and temporal envelope (effective duration/attack time). [Work supported by CRC, CFI, NSERC, CUIDADO European Project.]
Mapping soundscapes in urban quiet areas
Authors: Licitra Gaetano , Memoli Gianluca , Cerchiai Mauro , Nencini Luca
Published: October 2013

Innovative action plans in noise-polluted environments require the description of the existing soundscape in terms of suitable indicators. The role of these indicators, giving the ‘‘fingerprint’’ of a fixed soundscape, would be not only to measure the improvement in the sound quality after the action taken, but also to guide the designer in the process, providing a reference benchmark. One of the open questions on new indicators is the way they relate to existing ones and to people’s perception. The present work will describe a ‘‘Sonic Garden’’ in Florence, using both the ‘‘slope’’ indicator (constructed from the LAeq time history and related in previous studies to people’s perception) and classical psychoacoustical parameters (level, spectral structure, and perceived characteristics such as loudness, sharpness, fluctuation, and roughness). The latter parameters will be acquired using a binaural technique.
Acoustics of the Great Ball Court at Chichen Itza, Mexico
Authors: Lubman David
Published: October 2013

The ball game has played a central role in Mayan religion and culture for 5000 years. Thousands of ball courts have been discovered. The Great Ball Court (GBC) at Chichen Itza is a late development and is architecturally unique. Two remarkable acoustical features were noticed during excavation in the 1920s, but never explained or interpreted. A whispering gallery permits voice communication between temples located about 460 feet (140 m) apart. A profound flutter echo is heard between the two massive parallel walls of the playing field, about 270 ft (82 m) long, 28 ft (8.5 m) high, and 119 ft (36 m) apart. Until recently, most archaeologists dismissed acoustical features at Mayan sites as unintended artifacts. That is now changing. Stimulated by archaeological acoustic studies and reports since 1999, eminent Mayanists Stephen Houston and Karl Taube have reinterpreted certain Mayan glyphs as vibrant sounds and ballcourt echoes, and have famously called for a new archaeology of the senses, especially hearing, sight, and smell [Cambridge Archaeol. J. 10 (2) 261–294 (2000)]. By interpreting architectural, psychoacoustic, and cognitive features of the GBC in the context of ancient Mayan culture, this paper speculates that acoustical effects at the GBC may be original design features.
Probability characteristics of neural coincidence detectors in the brainstem
Authors: Krips Ram , Furst Miriam
Published: October 2013

Auditory neural activity in the periphery is usually described as nonhomogeneous Poisson process (NHPP), characterized as either EE or EI, which operates as a coincidence detector. In order to apply a general probabilistic analysis of those brainstem nuclei activity, the stochastic properties of the axons that exit the EE and EI nuclei is essential. An analytical analysis of the probability characteristics of the output of an EE nucleus (EEout) will be presented. Assuming that an EE nucleus receives inputs from two neurons, each behaves as an NHPP with instantaneous rates λ1 and λ2, and an output spike is generated if both spike at a coincidence window (Δ) which is relatively small (this matches biological findings). Then EEout is also a NHPP with instantaneous rate r(t)=λ1(t)∫t−Δtλ2(ζ)dζ+λ2(t)∫t−Δtλ1(ζ)dζ. A similar derivation was applied for an EI nucleus. We found also that the output activity is NHPP for a relatively small coincidence window (Δ). The obtained IR is r(t)=λe(t)[1−∫t−Δtλi(ζ)dζ], where λE and λI are the excitatory and inhibitory input IRs. On the other hand, for larger Δ, the output activity is not a Poisson process. Those derivations enable theoretical analysis and performance evaluation of large neural networks, which perform binaural tasks as ITD and ILD.
Flexural component and extensional component of vibration energy in shell structure
Authors: Ogushi Taito , Yahara Manabu , Mikami Masato , Kojima Naoya
Published: October 2013

In this research, the behavior of the flexural component and the extensional component of vibration intensity and their transmission in curved shells are presented. L-shaped shell model was employed as an analysis model of FEM. As FEM analysis methods, both the frequency response analysis and the transitional response analysis were employed. The flexural component and the extensional component of vibration intensity (VI) were calculated by the results of FEM analysis. In the flexural component of the VI, the vibration energy supplied in the flat part decreased at the boundary from the flat part to the curved part and VI vectors flew in circumferential direction in the curved part. In the extensional component of the VI, the vibration energy appeared at the boundary from the flat part to the curved part and most VI vectors flew parallel to the shell axis in the curved part. The total vibration energy of the flexural component and the extensional component was conserved. So, the vibration energy transformed to each other between the flexural component and the extensional component in L-shaped shell.
Speech style and stereotypical character in Japanese
Authors: Nakagawa Akiko , Sawada Hiroko
Published: October 2013

This study shows that ‘‘stereotypical character’’ is necessary to understand Japanese speech communication in addition to existing conceptions such as emotion, communicative strategy, register, and so on. Stereotypical character is here defined as a complex entity, consisting of information about gender, age, social status, physical features, characteristics, and speech style. The necessity of stereotypical character was shown through an auditory experiment involving a total of 70 speech sounds comprised of 15–19 short phrases (mean duration 1.4) selected from recordings of spontaneous speech of four adult female speakers of Japanese. Ten participants were asked to listen to these speech sounds randomly, and to classify them into four speakers. Each of the resulting auditory-perceptual categories was found to contain speech sounds from more than one speaker. Further analyses of these results suggested that the participants classified the speech sounds not according to invariant speaker characteristics but according to virtual stereotypical characters that are common in Japanese society. Therefore, such changeable speaker characteristics as ‘‘busybody’’ ‘‘thoughtful,’’ ‘‘high-handed,’’ and so on, can be elicited through speech sounds by Japanese speakers. [This work was partially supported by the Ministry of Education, Science, Sport, and Culture, Grant-in-Aid for Scientific Research (A), 16202006.]
Auditory-visual integration and lipreading abilities of older adults with normal and impaired hearing
Authors: Sommers Mitchell S. , Tye-Murray Nancy , Spehar Brent
Published: October 2013

The current study investigated how age-related hearing impairment affects lipreading and auditory-visual integration in older (above age 65) individuals. The performance of 53 normal-hearing and 24 mild-to-moderate hearing-impaired older adults was compared on auditory-only (A), visual-only (V), and auditory-visual (AV) speech perception, using consonants, words, and sentences as stimuli. All testing was conducted in the presence of individually specified multi-talker background babble, to obtain approximately equivalent A-only performance across the groups. In addition, we compared normal-hearing and hearing-impaired individuals on measures of auditory enhancement, visual enhancement, and auditory visual integration that were derived from the A, V, and AV performance scores. In general, normal-hearing and hearing-impaired older adults performed similarly on measures of visual-only and auditory-visual speech perception. The one exception to this finding was that hearing-impaired adults performed significantly better than normal-hearing participants on visual-only identification of words. Measures of visual enhancement, auditory enhancement, and auditory-visual integration did not differ as a function of hearing status. Overall, the results of the current study suggest that despite increased reliance on visual speech information, hearing-impaired older adults do not exhibit better visual-only speech perception or auditory-visual integration than age-matched normal-hearing individuals.
Human voice phoneme directivity pattern measurements
Authors: Katz Brian F. G. , Prezat Fabien , d’Alessandro Christophe
Published: October 2013

The application of directivity patterns to radiating sources into computer simulations and auralizations is common for loudspeaker models. Few applications include the directivity patterns of natural sources, partly due to the lack of sufficient data. This work presents the results of a detailed measurement study on human voice directivity in three-dimensions. Unlike previous studies that have used average directivity data over read phrases, this work presents results that are measured for a number of sustained individual phonemes. Details of the measurement protocol and posttreatment processing are presented. Comparisons are made relative to phoneme, f0, spectral characteristics, and associated mouth geometry for several talker subjects. Studies have also been made on the directivity of the singing voice. Specifically, the variations in directivity relative to level (piano, fortissimo, etc.) and projection as controlled by the singer have been investigated. Results of this work are applicable to speech production research, talker simulator design, room acoustic sound field prediction, and virtual reality systems with talking avatars.
Slowed speech spreading into reverberant environments; steady-state suppression improves speech intelligibility
Authors: Nakata Yuki , Murakami Yoshiaki , Hodoshima Nao , Arai Takayuki
Published: October 2013

Speech intelligibility is often decreased in reverberant environments. For improving speech intelligibility under reverberant environments, Arai et al. [Acoust. Sci. Technol. 23, 229–232 (2002)] suggested steady-state suppression, which suppresses steady-state portions of speech to reduce overlap-masking (causing degradation intelligibility) and improves speech intelligibility as preprocessing. Previous studies showed that speech intelligibility was improved through this processing under some reverberant environments [Hodoshima et al., J. Acoust. Soc. Am. 119(6), 4055–4064 (2006)]. On the other hand, speech intelligibility is known to be increased greatly by speaking slowly [Bolt and MacDonald, J. Acoust. Soc. Am. 21(6), 577–580 (1949)]. However, it is not optimal for improving speech intelligibility in terms of reducing overlap masking because vowels causing major parts of overlap masking are expanded by speaking slowly. Therefore, in the current study, we investigated the effects of steady-state suppression on speech perception with a decreased speech rate from 6 to 4 and 5 morae/s. Results showed that the slowest speech (4 morae/s) with steady-state suppression was the most intelligible. Also, steady-state suppression improved speech intelligibility at a speech rate of 4 morae/s in each reverberant condition (reverberation times of 1.5, 2.0, and 2.5 s). [Work partially supported by JSPS.KAKENHI (16203041).]
Consumers, products, and noise: The economic, social, and political barriers to reducing noise in consumer products sold in North America
Authors: Blomberg Leslie
Published: October 2013

The paper examines the economic, social, and political barriers to reducing noise in consumer products sold in North America. Included in the economic issues are the cost of noise control and whether or not consumers are willing to pay more for a quieter product. An equally important economic barrier, however, is that the marketplace currently does not have an effective mechanism to reward builders of quieter products, even if noise treatments were cost effective. There is very little information available to consumers about the noise levels of consumer products. Without their informed decisions in the marketplace, no signal reaches the manufacturers. Complicating this problem is the consolidation of the consumer product manufacturing sector and the consolidation in the retail sector. The social barriers include the public’s attitude towards noise (that it is an unavoidable cost of living in a technologically advance society) and the failure to see noise as a pollutant (that it is merely something unwanted). Political barriers include an absence of government involvement in consumer product noise, in terms of regulation, labeling, as well as a general concern for the issue.
Ultrasonic scattering in polycrystalline material with elongated grains
Authors: Ghoshal Goutam , Turner Joesph A.
Published: October 2013

The scattering of elastic waves in polycrystalline materials is relevant for ultrasonic materials characterization and nondestructive evaluation (NDE). Ultrasonic attenuation and diffuse backscatter measurements have been especially useful for extracting microstructural information such as grain size and for detecting flaws in materials. Accurate interpretation of experimental data requires robust scattering models. Such models often assume constant density and uniform grain size such that the scattering for grains with mainly spherical geometry is well understood. However, many structural materials are processed in such a way that the microstructure has grain elongation (e.g., from rolling). The scattering of elastic waves in such media must be understood well for design of effective materials inspection methods and for quantitative data analysis. For materials with grain elongation, the appropriate spatial correlation function is no longer isotropic such that closed-form solutions for attenuation cannot be achieved. Here, attenuation and diffuse backscatter expressions are derived as a function of wave propagation direction with respect to the axis of grain elongation. Numerical results are presented for materials of common interest under assumptions of statistical homogeneity. These results are anticipated to impact ultrasonic nondestructive evaluation of polycrystalline media. [Work supported by U.S. DOE.]
Finite-element method analysis of acoustic characteristics of the vocal tract with the nasal cavity during phonation of Japanese /a/
Authors: Matsuzaki Hiroki , Motoki Kunitoshi
Published: October 2013

For this study, the transfer functions and active sound intensities of a vocal tract model with and without a nasal cavity were computed using a three-dimensional finite-element method (FEM). The models were based on vowel data obtained by magnetic resonance imaging (MRI) of the vocal tract with a nasal cavity during phonation of the Japanese /a/. The oral cavity was also coupled with the nasal cavity in a three-dimensional volume of radiation. Effects of wall impedance were also examined. Coupling of the nasal cavity to the oral cavity indicated the following aspects. Additional peaks appeared below 3 kHz for the lossless condition. However, they disappeared in the simulation for the soft wall condition. The sound energy circulation did not occur in the simulation for the soft wall condition. Regarding effects of the wall boundary condition on the spectral envelope, three-dimensional simulations confirmed the upward shift of lower formant frequencies. However, disagreement of the formant frequencies between simulated and real speech should be investigated further by adjusting the wall boundary condition to a more realistic one.
Determining Bayesian evidence and decay time estimates in acoustically coupled volumes
Authors: Jasa Tomislav , Xiang Ning
Published: October 2013

Sound energy decay analysis is an important element in understanding acoustical properties of coupled volumes in architectural acoustics. A Bayesian model formulation using Monte Carlo algorithms [Xiang and Goggans, J. Acoust. Soc. Am. 110 1415–1424 (2001); Jasa and Xiang, ibid. 117, 3707(A) (2005)] has been applied to estimating both the decay times and decay order required in sound energy decay analysis. The need to focus on model selection in a Bayesian model formulation of sound energy decay analysis was presented by Jasa and Xiang [J. Acoust. Soc. Am. 119, 3343(A) (2006)] along with a discussion of the limitations of the existing Monte Carlo algorithms used for this purpose. This paper will present some recent algorithms that can overcome the limitations of a Monte Carlo approach to model selection and show how these algorithms can be applied to determining both the proper model and decay time estimates for acoustically coupled rooms.
Tongue dorsum location and tongue root retraction in alveolar and palatal clicks in the endangered language N/uu
Authors: Miller Amanda L. , Brugman Johanna , Howell Jonathan , Sands Bonny
Published: October 2013

Traill (1985) describes Xoo clicks as having velar posterior constriction locations (PCL). Miller et al. (to appear) show that the PCLs of Khoekhoe alveolar and palatal clicks are uvular and uvulo-pharyngeal. Ladefoged and Maddieson (1996) discuss clicks involving a uvular posterior release location (PRL) (and an implied velar PCL). An ultrasound investigation of velar and uvular pulmonic stops, alveolar and palatal velar clicks, and palatal uvular clicks, in the endangered language N/uu is presented. Results are for 15 repetitions of each consonant in the u context by four of the remaining speakers. The alveolar click has the tongue dorsum (TD) between the velar and uvular stops, and tongue root retraction (TRR) like the uvulars. The TD in the palatal click is also similar to the velar and uvular stops, but there is no TRR. The TD in the uvular palatal click is at the uvulo-phrayngeal location, and there is TRR similar to the uvular stop, in both the closure and the release. TRR in the alveolar-uvular and palatal-uvulo-pharyngeal clicks explains their phonological patterning with uvulars. The lack of TR retraction in the palatal click explains its patterning with velars. [Work supported by NSF, BCS ♯0236735.]
Quantifying the Lombard effect in different background noises
Authors: Giguère Christian , Laroche Chantal , Brault Émilie , Ste-Marie Julie-Catherine , Brosseau-Villeneuve Marianne , Philippon Bertrand , Vaillancourt Véronique
Published: October 2013

The Lombard effect of increasing one’s vocal effort in the presence of background noise has been quantified by Pearsons et al. (1977) as a 0.6-dB increase in speech levels for each dB increase in the background noise up to a ceiling level. Lombard speech has also been investigated in other studies with variable results. This study reports data on the effect of different noises on (1) the slope of the function relating speech levels and noise levels and (2) the spectral structure of speech. Twenty normal-hearing adults were asked to read aloud ten sentences from the hearing in noise test (HINT) to an experimenter seated 1 m away, in quiet and in various noises (white, speech spectrum, babble, and restaurant) presented in the sound field at 60 and 75 dBA. Preliminary findings show that increases in speech levels in natural environmental noises (restaurant and babble) most closely follow Pearsons’ data, with a slope of 0.6 dB. In contrast, artificial noises (speech spectrum and white) were associated with lower slopes (0.2 and 0.4 dB, respectively). Findings of this study could be useful in a wider context of modeling the complete speech communication process from talker to listener.
Therapeutic ultrasound
Authors: Crum Lawrence
Published: October 2013

The use of ultrasound in medicine is now quite commonplace, especially with the recent introduction of small, portable, and relatively inexpensive, hand-held diagnostic imaging devices. Moreover, ultrasound has expanded beyond the imaging realm, with methods and applications extending to novel therapeutic and surgical uses. Among these applications are tissue ablation, acoustocautery, lipoplasty, site-specific and ultrasound mediated drug activity, extracorporeal lithotripsy, and the enhancement of natural physiological functions such as wound healing and tissue regeneration. A particularly attractive aspect of this technology is that diagnostic and therapeutic systems can be combined to produce totally noninvasive, image-guided, bloodless surgery. This general lecture will review a number of these exciting new applications of ultrasound and address some of the basic scientific questions and future challenges in developing these methods and technologies for general use in our society. We shall particularly emphasize the use of high-intensity focused ultrasound (HIFU) in the treatment of benign and malignant tumors as well as the induction of acoustic hemostasis, especially in organs that are difficult to treat using conventional medical and surgical techniques. [Work supported in part by the NIH, NSBRI, ONR, and DARPA.]
Edge diffraction in computer modeling of room acoustics
Authors: Svensson U. Peter , Calamia Paul T.
Published: October 2013

Computer modeling in room acoustics is typically based on geometrical acoustics techniques. Limitations with such methods include, among other things, a lack of diffraction modeling, which primarily leads to inaccuracies at low frequencies. The inclusion of diffraction modeling is quite straightforward for first-order diffraction, which can be combined with specular reflections of any order. One impractical aspect, however, is that the number of diffraction components can be extremely high, and grows faster (with the reflection order) than the number of specular reflections does. At the same time, the importance, or magnitude, of the diffraction components will differ over an immense range. This variation can be exploited by estimating the importance of each diffraction contribution by the magnitude of its onset, and skipping the remainder of the calculations for those that are deemed too weak. This will be demonstrated for some typical geometrical cases including a set of overhead reflectors, an orchestra pit, and a convex hall shape for which diffraction is less critical. Results indicate that ‘‘diffraction culling’’ can provide a significant reduction in computation time with only small effects on the overall responses for the tested geometries. [This research has been supported by the Research Council of Norway].
Detection distances of the sounds of large whales recorded on hydrophones in the offshore Gulf of Alaska
Authors: Stafford Kathleen , Moore Sue , Mellinger David
Published: October 2013

The current status of most species of endangered baleen whales, including blue, fin, and humpback whales, in the Gulf of Alaska is unknown due to a lack of basic information on distribution and seasonal abundance. Remote passive acoustic monitoring can provide this information for vocal whales. However, to begin to estimate an index of abundance of calling animals, the distance at which they can be detected needs to be determined. In order to estimate transmission loss, a parabolic equation acoustic propagation model was used to provide mean loss estimates along four transects at 0.1a intervals to 5a to the N, E, S, and W from each of four receivers moored in the sound channel for species-specific frequencies and at depths at which the animals are thought to produce sound. For all species and locations, the detection range was largely determined by the choice of ambient noise levels. This suggests that masking due to anthropogenic noise could limit the range over which these animals can be detected by the moored instrument and, more importantly, the range over which they might communicate.
Cetacean vocalization tracking using an adaptive Poisson rate estimator
Authors: Kenny Owen P. , McPherson Craig R.
Published: October 2013

This paper presents algorithms for tracking the formant structure of cetacean vocalizations using auditory modeling and adaptive filtering to estimate the Poisson intensity of nerve firing rates. These rates are in turn related to the instantaneous frequency of the formant vocalisation. The auditory model considered in this paper produces a process described as a spike train representing the auditory nerve firing, the Poisson intensity of which is determined by an underlying modulation process. Previous work [Kenny et al., Adaptive Filter for Speech Enhancement Using Poisson Rates from an Auditory Model, paper presented at the WESPAC VIII, Melbourne, Australia (2003); C. McPherson, Development of a Toolkit for Analysing and Localising Underwater Acoustic Signals (James Cook University, Townsville, 2005)] has shown that this modulation process can be evaluated from the conditional expectation of the Poisson rate given interspike arrival time observations. The paper also addresses the application of adaptive filters to update the estimator parameters for different acoustic environments, which is unknown. These algorithms have been applied to real field recordings of interacting false killer whales (Pseudorca crassidens) and results from experiment of shown individualisation and extraction of individual narrow-band vocalizations.
Ocean acoustic tomography using high-frequency systems
Authors: Porter Michael B. , Kim Katherine H. , Siderius Martin , Badiey Mohsen , Folegot Thomas , Group the KauaiEx
Published: October 2013

New system concepts have emerged in which large numbers of acoustic and environmental sensors are networked together in littoral areas. The spatial scales for these networks are much finer—features such as linear and nonlinear internal waves/tides can affect both network and sensor performance. A vision readily comes together in which ocean acoustic tomography is used to monitor the finescale, using the network to relay travel-time information in real time and also to probe the environment. Further, travel-time information may be assimilated into an ocean circulation model together with direct current and temperature measurements from fixed and mobile platforms to provide nowcasts and forecasts of the local ocean weather. The acoustic tomography in this vision uses a much higher frequency band (e.g., 8–16 kHz) than has traditionally been used and there has been some skepticism about the feasibility of doing tomography in this band. Using data from two large experiments in Hawaii (KauaiEx and MakaiEx), we show that (1) HF signals can be used to clearly measure the channel impulse response, (2) changes in the impulse response are directly linked to changes in the oceanography, and, therefore, (3) HF signals can be used to invert for the ocean structure.
Ultrasound-enhanced thrombolysis
Authors: Holland Christy K. , Datta Saurabh , Vaidya Sampada S. , Meunier Jason M. , Shaw George J. , Coussios Constantin-C.
Published: October 2013

Substantial enhancement of recombinant tissue plasminogen activator (rt-PA) thrombolysis can be achieved with ultrasound, suggesting its use as an adjunctive treatment in thrombolytic therapy for stroke. This enhancement may be due to acoustic cavitation, thermal effects, forced convection of rt-PA, or biochemical enhancement. The effect of US duty cycle on the lytic efficacy of pulsed 120-kHz ultrasound in a human in vitro clot model was investigated, using a time-lapse microscopic imaging technique. The initial lytic rate increased linearly with duty cycle. In addition, a passive cavitation detection scheme was used to explore stable and inertial cavitation as potential mechanisms for ultrasound-enhanced thrombolysis. Porcine clots were exposed to pulsed ultrasound and rt-PA in vitro for 30 min using four separate ultrasound treatment regimes: (i) no cavitation (0.15 MPa); (ii) stable cavitation alone (0.24 MPa), (iii) stable and inertial cavitation combined (0.36 MPa); or (iv) no ultrasound. Percent clot mass loss after each treatment was used to determine thrombolysis efficacy. Clots exposed to stable cavitation and rt-PA exhibited the highest mass loss. Significant enhancement of thrombolysis correlates with presence of cavitation and stable cavitation appears to play a more important role in the enhancement of thrombolysis.
Developing novel therapeutic strategies through biological effects of ultrasound
Authors: Paliwal Sumit , Mitragotri Samir
Published: October 2013

Ultrasound-mediated cavitation has been shown to facilitate delivery of drugs across biological barriers in cells and tissues. However, these nonthermal mechanisms can also trigger various biochemical pathways in the biological milieu, opening up doors to interesting ultrasonic therapeutic applications. For example, a brief application of ultrasound followed by treatment with quercetin (a poorly potent chemotherapeutic drug) becomes selectively cytotoxic towards prostate and skin cancer cells. As opposed to the increased delivery of drugs to cancer cells, this treatment methodology is hypothesized to be mediated through inhibition of heat shock protein-hsp72, a vital stress-protein essential for the survival of cancer cells. Additional examples demonstrating the use of ultrasound’s biological effects for therapeutic applications will be discussed. For example, ultrasound is demonstrated to work as a vaccination adjuvant by activating the Langerhans cells (immune cells present in skin) and leading to a robust immune response against tetanus toxoid. Overall, this presentation will demonstrate the increasing importance of ultrasound’s role as a biological sensitizer enabling novel therapeutic strategies, a role which is beyond its conventional use as a drug delivery tool.
Effects of altered auditory feedback on piano performance
Authors: Takahashi Noriyuki , Tsuzaki Minoru
Published: October 2013

Some studies in the field of developmental psychology have suggested that a complex task executed by an expert includes the automated and sequential execution of some subordinate skills. In this study, we regard the development of musical performance as the length of motor control of a musical instrument carried out with a feedforward process. We then verify this assumption through a performance experiment using skilled and unskilled pianists. Both pianists play one musical figure repeatedly in the experiment. In the middle of the performance, a mapping function between the key velocity and its sound output is altered. It is expected that pianists would try to correct their performance when receiving this altered auditory feedback. By checking the point at which they start to correct, we can infer the length of the unit used with the feedforward process. It is expected that the correction would occur at a specific point in the musical figure if skilled pianists have a certain length unit of automated motor control. On the other hand, the point of correction would have less consistency in the case of unskilled pianists. [Work supported by the Grant-in-Aid for Scientific Research A, No. 16200016, JSPS.]
A jazz arrangement system yielding a guitar chord-form sequence
Authors: Sawayama Koji , Emura Norio , Yanagida Masuzo , Miura Masanobu
Published: October 2013

Many guitar scores of rock or pop music arranged in jazz style are available all over the world. The amount of software for arranging given sequence of chord names and books of arrangement in jazz style has been growing for these past decades. Using this software, even amateur guitarists can play their favorite tunes in jazz style without knowledge of jazz theory. Most of these software systems, however, do not take musical appropriateness into account. So, sounds of chord-form sequence output by these software systems often mismatch the input melody. Proposed here is a system that generates a chord-form sequence in jazz style for a given set of melody and chord-name sequence. The system analyzes an input set of given melody and chord-name sequence based on jazz theory, and yields the chord-form sequence considering the melody line. It is confirmed that the chord-form sequence yielded by this system meets user requirements and is more preferable than that by software systems on the market. [Work supported by Academic Frontier Project, Doshisha Univ., Knowledge Cluster Project, MEXT, Grant-in Aid for Scientific Research (No.16700154), MEXT, HRC, Ryukoku Univ.]
Applications of large-scale finite-element sound-field analysis utilizing Architectural Institute of Japan-benchmark platform
Authors: Otsuru Toru , Okamoto Noriko , Okuzono Takeshi
Published: October 2013

A computational system, namely large-scale finite-element sound-field analysis(LsFE-SFA), has been developed by the authors. It is based on the finite-element method (FEM) with an iterative solver of linear equation that can reduce memory requirement of the system drastically. To show the effectiveness of LsFE-SFA, sound fields in a reverberation room and in a music hall were analyzed. The problem settings are provided by the web site of ‘‘AIJ-Benchmark Platform for Computational Acoustics,’’ which is run by a subcommittee of Architectural Institute of Japan (AIJ). First, sound-pressure level distribution maps at about 300 points in the reverberation room computed by LsFE-SFA were compared with those by measurement to show the accuracy of LsFE-SFA to be within 1-dB difference. The frequencies investigated were in 1/3-octave bands with the center frequency raging from 63 to 250 Hz. In the computations, boundary absorption is modeled by use of normal impedance that was measured in situ by use of the authors’ newly proposed method, or EA-Noise method. Next, the diffuser shapes on the walls in the music hall were examined by LsFE-SFA to give better diffuseness. The investigations showed the effectiveness of LsFE-SFA.
The program battle at Ganz Hall
Authors: Tillery Candice , Pleckham Jay
Published: October 2013

Current modeling programs offer a wide range of analysis and prediction tools, as well as detailed modeling capabilities and user friendly formats. However, these tools are only useful if they can do their job correctly. The accuracy of the program, its cost, and its relevance to the environment in question are all vitally important when selecting software for a project. This paper addresses these issues through a comparison of two of today’s most popular modeling programs: CARA and EASE. An acoustical analysis was performed on Roosevelt University’s Ganz Hall, which seats 195 people and is used primarily for student recitals. Data were acquired concerning the hall’s reverberation and frequency response. Numerous calculations were performed to determine the room’s musical clarity, speech clarity, and early decay time. The hall was then modeled in the two programs in question, and the results were compared to determine each program’s accuracy.
Humpback whale social sounds: Sources levels and response to playback
Authors: Noad Michael J. , Dunlop Rebecca , Cato Douglas H. , Stokes Dale , Miller Patrick , Biassoni Nicoletta
Published: October 2013

Humpback whale ‘‘social sounds’’ appear to be used in communication when whales interact but they have received little study in comparison to the song. During experiments as part of the Humpback whale Acoustics Research Collaboration (HARC), whales migrating past the study site on the east coast of Australia produced a wide range of social sounds. Whales were tracked visually using a theodolite and singers were tracked acoustically using an array of five widely spaced hydrophones. Source levels of social sounds were calculated from the received level of the sounds, corrected for measured propagation loss. Playbacks of social sounds were made using a J11 transducer and the consequent reactions were recorded in terms of the change in direction of the migrating whales in relation to the playback position. In one playback, a DTAG was place on a female with calf. Playback of social sounds resulted in significant changes in the course of the migrating whales, in some cases towards the transducer while in others it was away from the transducer. From the estimates of source levels it is possible to assess the effectiveness of the playback and the range of influence of social sounds. [Work supported by ONR and DSTO.]
Megapclicks: Tagged humpback whales produce click trains and buzzes during foraging
Authors: Stimpert Alison K. , Au Whitlow W. L. , Johnson Mark P. , Wiley David N. , Arsenault Roland
Published: October 2013

Mysticetes and odontocetes differ in many morphological and behavioral aspects related to feeding. Odontocetes echolocate using clicks to localize prey, while the mechanism through which mysticetes orient and find food is unknown. In this study, DTAGs were deployed on four humpback whales (Megaptera novaeangliae) observed feeding off the northeastern United States. From two of the four tagged whales, bouts of clicks produced with a temporal pattern resembling odontocete echolocation were recorded and 102 bouts of megapclicks were identified. Spectrally, megapclicks were unlike previously reported humpback sounds or odontocete clicks, and also had much lower amplitudes (peak frequency ∼1700 Hz, RL 148±6 dB Re: 1 uPa peak). Interclick intervals (ICI) were bimodally distributed (peaks at 25 and 80 ms), with shorter ICIs occurring at the end of megapclick bouts, in a pattern similar to an odontocete terminal buzz used in foraging. Behavioral sensor data supported a possible foraging function for megapclicks. All megapclick bouts occurred during nighttime hours, and the terminal buzz was associated with a sharp body roll of greater than 70 deg. Low source levels, among other characteristics, contraindicate an echolocation function; however, further analysis and research is required to distinguish among this and other hypotheses for sound function.
On the use of the Teager energy operator for the detection of clicks in free-ranging dolphins
Authors: Roch Marie A. , Soldevilla Melissa S. , Burtenshaw Jessica C. , Henderson E. Elizabeth , Wiggins Sean M. , Hildebrand John A.
Published: October 2013

The detection of individual clicks produced by odontocetes is useful for many bioacoustic tasks such as the analysis of interclick interval, classification of odontocete species, etc. Automation of this task is required for the large data sets gathered by remote instruments that can collect terabytes of information over short time periods. A method is presented that locates individual clicks using the Teager energy operator, which is a time-domain metric designed to measure fast variations in signal energy. The Teager energy of a high-pass filtered signal is analyzed by a rule-based classifier that determines the location of individual clicks. The click start can be determined with very high accuracy. Click ends are reasonably well characterized, but the ends of clicks are difficult to determine, even by human experts, due to the influence of external factors such as acoustic reflections. The proposed method is compared with existing techniques and is demonstrated on the calls of several species of free-ranging odontocetes resident in the Southern California Bight and the Gulf of Mexico: bottlenose dolphins (Tursiops truncatus), short and long beaked common dolphins (Delphinus delphis, Delphinus capensis), Pacific white-sided dolphins (Lagenorhynchus obliquidens), and Risso’s dolphins (Grampus griseus).
First data from sea trials with the new MS70 multibeam sonar
Authors: Ona Egil , Dalen John , Knudsen Hans Petter , Patel Ruben , Nonboe Andersen Lars , Berg Sverre
Published: October 2013

The new multi-beam sonar, MS70, is a horizontally observing sonar yielding very high spatial resolution when operating all 500 beams, covering the frequency band 75–112 kHz. The sonar has undergone sea trials from R/V G. O. Sars from December 2005. The presentation includes preliminary results obtained during this period. Topics covered will be sonar performance objectives, calibration methods, and preliminary results from calibration and school data acquisition. Examples of raw and processed 3-D and 4-D data from a stationary and surveying vessel on small sprat schools and large herring schools will be shown.
Measurement of scattering directivity and behavior of fish schools using multibeam sonar
Authors: Cutter George , Demer David
Published: October 2013

Fish dispersion and abundance are commonly estimated from volume backscattering coefficients (sv) of animals located directly beneath the survey vessel, inside a narrow transducer beamwidth. Fish density (♯/m2) is estimated from a ratio of integrated sv and a representative backscattering cross-sectional area. Fish biomass is estimated from the product of fish density and the area sampled. Uncertainty in biomass estimates can arise from small sampling volumes, and the scattering directivities of the fish coupled with their orientations relative to the acoustic beam. Multibeam sonars can be used to increase the observational volumes, but add the complexity of a wider range of incident angles. If fish size and packing density are constant throughout a school, then the variation in sv versus aspect angle can be attributed to fish orientation. With modeling and multibeam sonar measurements, the following null hypotheses are explored: (1) The variability of sv versus roll angle is nearly uniform; (2) For measurements made with beams at or near vertical, sv variability is primarily due to the pitch angle; (3) For measurements with nonvertical beams, such as the outer beams of multibeam echosounders, sv variability is primarily due to the yaw angle.
The Long-range Ocean Acoustic Propagation EXperiment (LOAPEX): An overview
Authors: Mercer James A. , Howe Bruce M. , Andrew Rex K. , Wolfson Michael A. , Worcester Peter F. , Dzieciuch Matthew A. , Colosi John A.
Published: October 2013

The Long-range Ocean Acoustic Propagation EXperiment (LOAPEX), conducted in the NE Pacific Ocean, provided acoustic transmissions from a ship-suspended source at eight widely separated stations, and from a cabled acoustic source near the Island of Kauai, HI. The transmissions were received on several bottom-mounted horizontal hydrophone arrays distributed about the NE Pacific Ocean Basin and two, nearly colocated, vertical hydrophone line arrays spanning roughly 3500 m of the water column. Ranges varied from 50 km to several Mm. The goals of the experiment are (i) to study the evolution, with distance (range), of the acoustic arrival pattern and in particular the dependence of the spatial and temporal coherence; (ii) to investigate the nature of the deep caustics and the associated arrivals well below their turning depths; (iii) to analyze the effects of the ocean bottom near the bottom-mounted acoustic source cabled to Kauai; and (iv) to produce a thermal snapshot of the NE Pacific Ocean. The experiment goals, design, and methods are described as well as preliminary data results. [Work supported by ONR.]
Ray and finite frequency kernel stability in the presence of realistic eddies
Authors: Cornuelle Bruce D. , Dzieciuch Matthew A.
Published: October 2013

Many recent studies have focused on the instability of ray paths (and therefore ray sampling kernels) in an ocean sound-speed field perturbed by internal waves. In many parts of the world’s oceans there is synoptic scale eddy and planetary wave activity that produces sound-speed anomalies of larger scale than the internal waves, and of equal or larger magnitude. These are the features to be imaged by ocean tomography experiments, but the linearized forward problem that relates the travel time anomaly of the observed rays to the sound-speed anomalies may be invalid for realistic levels of eddy variability. This problem has been studied in the past for ray kernels by a number of authors, some of whom have concluded that nonlinearity requires iteration of the inversion process. We will compare and contrast the linearity of ray travel time kernel, finite frequency travel time kernels, and finite frequency kernels for other observables, such as pulse shape, in the presence of realistic variability for the N. Philippine sea, as estimated by ocean models and historical data. The travel time signals and nonlinearity due to the synoptic variability will be compared to that for internal waves. [Work supported by ONR.]