bluuebunny/crossref_metadata_2025 huggingface dataset:
Audible-frequency medical diagnostic methods: Past, present and future
Authors: Sarvazyan Armen
Published: October 2013

From time immemorial, the medical practitioners used audible-frequency diagnostic methods (percussion, pulse tone analysis, lung, heart and abdominal sound listening) for diagnosing and treatment of ailments without much help from other tests. During the last century, despite the fact that the stethoscope became the sign of the physician, auscultatory techniques are becoming outmoded and are often considered of little clinical value in comparison with many other modern diagnostic technologies. But obviously, there is rich information on the normal and diseased states of human organs in audible-frequency signals since characteristic times for many physiologic processes and resonance frequencies of anatomical structures are in that frequency range. In recent years, numerous emerging technologies started to bring new life into the ancient diagnostic approaches using low-frequency signals. Significant part of these new technologies are based on ultrasonic methods such as remote detection of tissue oscillation using the Doppler technique and especially on emerging ultrasonic technologies based on the use of acoustic radiation force. This talk presents an overview of current trends in the development of methods realizing the tremendous untapped medical diagnostic potential of sonic range acoustics.
Feasibility of shear-mode transcranial ultrasound imaging
Authors: Clement Greg T. , White P. Jason , Hynynen Kullervo
Published: October 2013

Despite ultrasound’s potential to provide a low cost method for imaging blood flow and diagnosing certain brain disorders, distortion and low signal to noise ratios caused by the skull have severely limited the use of existing clinical devices, such as trancranial Doppler sonography. Presently we investigate the potential to propagate ultrasound through the skull with reduced distortion and higher signal amplitudes by using high incident angles. In such cases the ultrasound angle of entry is set beyond Snell’s critical angle for the longitudinal pressure wave, so that propagation in the bone is purely due to a shear wave. This wave then converts back to a longitudinal acoustic wave in the brain. This conversion from a longitudinal wave (skin) to a shear wave (skull) and again to a longitudinal wave (brain) does not necessarily produce a highly distorted or small-amplitude wave. Basic images and measurements of shear speed-of-sound and attenuation values for ex vivo human skull bone will be presented for frequencies between 0.25 MHz and 2 MHz. Similar measurements with porcine samples will also be shown, indicating the large discrepancy between shear characteristics of the two species; the porcine samples showing no detectable shear mode.
Tuning the lower resonances of carved Baltic psalteries by adjusting the areas of the sound holes
Authors: Peekna Andres , Rossing Thomas D.
Published: October 2013

Previous work has shown that with carved Baltic psalteries it is highly desirable to have a body-resonance with high radiating efficiency between the keynote and the tone above. In many cases, it is also desirable to have a body-resonance close to the low dominant. The frequencies of the two lowest body-resonances can be adjusted, to some extent, by adjusting the areas of the sound holes. We describe two trials. In one case, the instrument started out with no sound holes, and their areas were increased step by step, mostly according to listening trials, but the results were also verified by electronic TV holography. In the second case, the instrument started with excessive sound hole area. In this case, the listening tests first determined the extent of sound holes to be covered by sufficiently stiff material. The findings were subsequently confirmed by electronic TV holography. In both cases, a point was reached below which (smaller areas) the sound quality became less bright and more dull, and above which the sound quality was perceived as good. In each case, an optimum was reached.
Soundscape assessment
Authors: Axelsson Osten , Berglund Birgitta , Nilsson Mats E.
Published: October 2013

In order to improve the quality of the soundscape it is necessary to know its descriptive and evaluative properties, and the relationships between these properties. This was explored in a listening experiment with 100 participants (48 women, 52 men; mean age 25.6 years). Each participant scaled 5 out of 50 soundscapes with regard to 116 single verbal attributes, using a visual analogue scale of agreeableness. In addition, acoustical properties of the soundscapes were assessed. A principal component analysis identified two major evaluative components, labeled Hedonic Tone and Eventfulness. Furthermore, it was found the mere presence of common sound sources, regardless of sound level, correlated significantly with these evaluative components. Technological sounds (e.g., traffic noise) were negatively associated with both Hedonic Tone and Eventfulness, while a positive association was found between Hedonic Tone and sounds of nature (e.g., bird song), and a positive association was found between Eventfulness and human sounds (e.g., human voices). These relationships lead to the hypothesis that introduction of nature and human sounds, in combination with the reduction of technological sounds may improve the quality of soundscapes considerably.
Parabolic approximation versus geometrical acoustics for describing nonlinear acoustic waves in inhomogeneous media
Authors: Khokhlova Vera A. , Averianov Mikhail V. , Cleveland Robin O. , Blanc-Benon Philippe
Published: October 2013

Propagation of intense periodic acoustic waves in inhomogeneous media is studied in the nonlinear geometrical acoustics (NGA) approximation and using nonlinear parabolic equation (NPE). Various types of 2-D inhomogeneities are considered, such as a phase screen, single Gaussian inhomogeneities, and random inhomogeneous media. Distributions of acoustic rays are obtained by numerical solution of the eikonal equation. Pressure field patterns are calculated numerically with account for nonlinear effects and diffraction using a frequency-domain algorithm for the NPE. The location of caustics and shadow zones in the ray patterns are compared with the results of the parabolic model for the areas of increased and decreased sound pressure. Both linear and nonlinear propagation is investigated in order to reveal the validity of NGA in predicting the acoustic field structure and to better understand how the combined effects of inhomogeneities, diffraction, and nonlinearity determine the overall peak and average parameters of the acoustic field. It is shown that NGA does not accurately represent all the locations of enhanced or reduced acoustic pressure even for single scattering inhomogeneities, and the discrepancies become larger for smaller size inhomogeneities and at longer distances in random inhomogeneous medium. [Work supported by CNRS, RFBR, and NIH Fogarty.]
Comparing linear regression models applied to psychophysical data
Authors: Tang Zhongzhou , Richards Virginia M. , Shih Andrew
Published: October 2013

Relative weights for a profile analysis task were obtained using four regression/classification models; correlation coefficients, linear regression, logistic regression and probit regression. The aim of the study was to examine the impact of the choice of model on the accuracy and the efficiency with which the relative weights were determined. A yes/no task was used with observers indicating whether or not there was an increment in level to the central component of an 11-component standard. On each presentation the amplitudes of the individual components of the complex were randomly perturbed using draws from a normal distribution. When a large number of trials (1250) were used to estimate the relative weights, the four methods generated nearly identical weight estimates. When smaller numbers of trials were used (112), the different methods generated patterns of relative weights that were largely similar, and the patterns deviated only modestly from the large-number solution. In terms of efficiency, the error boundaries of the different methods were nearly indistinguishable. All in all, the number of trials needed to obtain statistically significant weights is sufficiently large that there is no apparent advantage of using one method over the others. [Work supported by NIH/NIDCD.]
Differences in loudness of tone complexes with positive and negative Schroeder phase
Authors: Mauermann Manfred , Hohmann Volker
Published: October 2013

Tone complexes with positive (m+) and negative Schroeder phase (m−) have an identical long-term spectrum, the same temporal envelope but are inverted in time. They show large differences in masking efficiency most probably being related to a different cochlear representation. The current study investigates to which extent loudness perception is affected similarly by the different phase characteristic of m+/m− stimuli. Therefore, the loudness of m+/m− stimuli (1.6 octave bandwidth) was matched in seven normal hearing and three hearing impaired subjects. In the first experiment the fundamental frequency f0 of the tone complexes was varied from 2–1536 Hz for different center frequencies at a soft level of the reference signal (m−). In normal hearing subjects the m+ stimuli need a 6 dB higher level to be perceived as equally loud as the respective m− stimuli (for f0 in the range of 24–96 Hz). In the second experiment the difference in loudness of m+/m− was investigated as function of the of the reference-stimulus level (5–80 dB SL) at a center frequency of 2660 Hz and f0 at 48 Hz. The largest differences in loudness were found for levels between 40–60 dB, clearly reduced for higher and lower levels of the reference stimulus.
Evidence for a cancellation mechanism in perceptual segregation by differences in fundamental frequency
Authors: Culling John F. , Linsmith Gareth M. , Caller Tracy L.
Published: October 2013

Identification of target speech material is better when it differs in fundamental frequency (F0) from interfering speech material. Two experiments tested the idea that this effect is mediated by a cancellation process that perceptually removes sound on one F0. Expt. 1 used monotonized target speech at 112.5 Hz F0 against two monotonized interferers. The F0s of the interferers were either both 112.5 Hz, both 126 Hz, or 100 and 126 Hz. Speech reception thresholds (SRTs) were about 3.5 dB lower when the two interferers shared a 126 Hz F0 than in the other two conditions, which differed by only 0.3 dB. These results are consistent with a cancellation mechanism that is able to remove sounds at only a single F0. Expt. 2 replicated and extended Expt. 1, testing whether the results were affected by the allocation of the target and interferers to particular F0s. When all sentences shared a common F0, SRTs were now 1–1.5 dB higher than when they were all different. However, all 4 SRTs for interferers sharing the same F0 (differing from that of the target by 2 or 4 semitones) were lower than all three of the SRTs for interferers with independent F0s.
Comparison of speech intelligibility measures
Authors: Laures Jacqueline S. , Weismer Gary G.
Published: October 2013

The speech intelligibility of dysarthric speakers is perceptually measured by one of the following four techniques: direct magnitude estimation with a modulus, free modulus magnitude estimation, interval scaling, and transcription. Weismer and Laures (2002) suggest that magnitude estimates may provide a more complete representation of speech intelligibility than other methods of measurement because it may be more sensitive to non-segmental aspects of speech, such as prosody. However, the empirical data supporting such a statement is quite limited. The purpose of the current study is to explore the relationship of the four different measurement techniques to determine if one approach may provide a more accurate determination of the speech intelligibility of dysarthric speakers. Twelve listeners measured the speech of six dysarthric speakers and two healthy control speakers using the four different measurement techniques. Each speaker produced three sentences twice. The sentences were presented via a loudspeaker in a sound attenuated booth. Listeners rated the sentences using the four techniques. The order of techniques used was counterbalanced. A correlation analysis revealed that the four techniques were highly related. Implications of this finding are discussed.
Perceptual, acoustic, and tongue shape measures during /r/ production pre- and post-treatment using visual feedback from ultrasound: case studies of two adolescents
Authors: Adler-Bock Marcy , Bernhardt Barbara , Bacsfalvi Penelope , Gick Bryan
Published: October 2013

This study examined the effectiveness of using visual feedback from ultrasound in remediation of persistent /r/ errors. Ultrasound provided the participants and the clinician with a dynamic sagittal or coronal image of the tongue during speech production. The participants in this study were two adolescent boys ages 12 and 14 who were not able to produce an on-target North American /r/. Both participants had received at least one year of traditional /r/ therapy without improvement. Treatment was provided over 13 one-hour sessions using visual feedback from ultrasound. Initially, /r/ was broken down and rehearsed as individual motor targets (tongue tip, body, root); these components were then practiced in combination to produce /r/ in isolation, then in syllables, words, and phrases. Post-treatment changes in /r/ production were captured through transcription, acoustic analysis, and tongue shape measurement. Both participants /r/ productions were rated as having more tokens of on-target /r/ post-treatment. Acoustic results supported these findings with the third formant lowering post-treatment. Tongue shape measures indicated that the participants tongue shapes were more similar to the modeled /r/ tongue shape post-treatment. These case studies suggest that visual feedback as provided by ultrasound may be a useful adjunct to speech (re)habilitation.
The influence of severity of speech involvement on acoustic measures in dysarthria
Authors: Kim Yunjung , Weismer Gary , Kent Ray D.
Published: October 2013

Several different acoustic measures have described the articulatory deficit and predicted the overall speech intelligibility deficit in speakers with dysarthria. The articulatory basis of acoustic variables that predict speech intelligibility variations across speakers have been thought to be the ones that should be manipulated clinically for maximum therapeutic effect. For example, F2 extent and slope are known to have strong correlations with speech intelligibility measures, across dysarthric speakers. This may suggest that within-speaker manipulation of magnitude and/or speed of articulatory movements will, if successful, result in improved speech intelligibility. Some of our previous work [Weismer et al., 2001, Folia Phoniat. Logopaed.] indicates, however, that these measures may not be predictive of within-speaker fluctuations in intelligibility, but rather are indices only of across-speaker variation in severity. The large data base of dysarthric speakers at UW-Madison permits us to begin to determine how much variability exists for measures like F2 slope in a relatively large group of speakers with homogeneous speech severity. This paper will report results of F2 extent and slope measures for speakers with relatively mild speech involvement. If the measures are primarily tied to severity, they should not vary much within a homogeneous group of speakers. [Work supported by DC00319.]
Perception of coarticulation in gated words by dyslexic and non-dyslexic children
Authors: Keating Patricia , Manis Frank , Bruno Jennifer , Nakamoto Jonathan
Published: October 2013

In an auditory word gating task, listeners are presented with portions of words, and try to identify these acoustic fragments as lexical items. It has been shown that children need more acoustic information than adults to succeed, and that dyslexic children can require more information than other children. It is also known that adults can use early acoustic cues to identify features of upcoming segments. For example, in English anticipatory vowel nasalization implies that a nasal consonant will follow, and similarly anticipatory lateralization. Our study asked whether dyslexic children are impaired in their perception or use of such anticipatory coarticulatory information. Successive gates from test words that ended in a nasal (8 words) or /l/ (4 words), or control words with final oral stops, were blocked by length and presented to 26 dyslexic and 26 non-dyslexic children. Responses were audiorecorded and later transcribed; responses were scored re both the full word and the nasality/laterality of the final consonant. Dyslexics as a group required more gates to identify nasality, but not whole words. Language-impaired dyslexics required more gates to identify whole words as well as nasality. Performance on the gating task significantly predicted reading ability when age and IQ were controlled.
Driving performance and auditory distractions
Authors: Slawinski Elzbieta B. , MacNeil Jane F. , Motamedi Mona , Zendel Benjamin R. , Dugdale Kirsten , Johnson Michelle
Published: October 2013

Driving performance depends on the ability to divide attention during different tasks. In spite of the fact that driving abilities are associated with visual stimulation, driving performance depends on attention to stimulation and/or auditory distraction. Research shows that listening to the radio is a principal auditory distracter during the time of driving (Brodsky, 2002). In the laboratory a few experiments were conducted on the auditory distraction (e.g., music, stories) and signal processing by young and older drivers. Results show that older subjects involved in listening to the stream of information (independent of the hearing status) require higher intensity of the auditory stimulation than younger drivers. It was shown that cognition plays a role while listening to auditory stimuli. Moreover, it was demonstrated that driving performance was influenced by the type of performed music. A portion of these experiments and their results were presented at the Annual Meetings of CAA in 2002 and 2003 as well as being published in the Journal of Psychomusicology 18, 203–209. Complete results of the experiments will be discussed.
Nonlinear scattering of acoustical waves on sphere after passing the obstacle
Authors: Zagrai Nickolay , Zagrai Andrey , Starchenko Irene
Published: October 2013

The problem of nonlinear interaction of acoustical waves in the system medium-obstacle-medium-sphere was considered. The expressions for secondary field of parametric array were obtained. The contributions of components were evaluated on separated processes of non-linear interaction before and after the obstacle as for the primary signals field as for the secondary fields of combinational frequencies waves. The possible practical applications were also discussed.
A system to evaluate and compare transducers used for lung sound research
Authors: Kraman Steve S. , Wodicka George R. , Pressler Gary A. , Pasterkamp Hans
Published: October 2013

Since lung sounds were first recorded and analyzed in the 1960s, a variety of custom made or adapted transducers have been used for detecting these sounds. There is no standard lung sound transducer nor have those in use been adequately compared. To address this problem, a test platform was constructed that provides a stable and reproducible sound source coupled to a viscoelastic surface that is mechanically and acoustically similar to human skin and subcutaneous tissue as judged from comparisons with similar thicknesses of fresh meat and fat. The device was designed to be equally suitable for air-coupled microphones and for accelerometers. When driven by a broadband noise source, the acoustic amplitude at the surface of the platform was found to be relatively uniform from 100 to 1200 Hz. The system was used to evaluate a variety of lung sound transducers. They were found to vary significantly in frequency response with no device appearing to be adequate as an all-purpose lung sound sensor. It is concluded that lung sound characteristics are likely to be significantly affected by the type of sensor used to acquire the sound. This makes comparisons between differently equipped laboratories difficult.
Recent developments in the characterization of anisotropic, biological media utilizing magnetic resonance elastography
Authors: Romano Anthony J. , Valdivia Nicolas P. , Abraham Philip B. , Bucaro Joseph A. , Rossman Philip J. , Ehman Richard L.
Published: October 2013

In this paper, we present recent developments in the characterization of anisotropic, biological media utilizing displacements measured with dynamic MRE. In one approach, a waveguide constrained analysis is applied to physical structures (such as muscle), which evaluates the velocities of wave propagation along arbitrarily oriented fibers or fiber bundles in a local fashion, utilizing a spectral filter and a sliding window, spatial Fourier transform. In a second approach, the anisotropic equations of elasticity, in variational form, are inverted for a determination of the complex moduli comprising the medium. Issues concerning ill-conditioning, the effects of boundary conditions, and multiaspect excitation requirements will be addressed, as well as a discussion concerning the models which are appropriate for various physical situations. These two complementary methods of analysis will be demonstrated utilizing both phantom as well as in vivo dynamic displacement measurements.
Local inversion of transient shear-wave propagation for elasticity and viscosity mapping in soft tissues
Authors: Bercoff Jeremy , Tanter Mickael , Fink Mathias
Published: October 2013

Observation of transient shear-wave propagation in soft tissue is of great interest for the study of tissue viscoelastic properties. In previous work, we introduced a technique, called Supersonic Shear Imaging (SSI), able to generate transient shear waves using the acoustic radiation force and image their propagation in real time in soft tissues. In this work, a local inverse problem of the shear wave propagation permitting the recovery of shear elasticity and viscosity is presented. Compressional and shear waves are decoupled by applying the curl operator to the experimental 2-D displacement field. The role of viscosity on the accuracy of the elasticity estimation is studied. The influence of out of plane shear propagation on the inversion algorithm is discussed. Finally, in media presenting shear viscoelasticity heterogeneities, finite difference simulations are used to study the spatial resolution of the algorithm and its sensitivity to the signal-to-noise ratio. Experiments on calibrated tissue-mimicking phantoms presenting different viscoelastic properties are presented validating the simulation results. First in vivo results on female breasts are presented.
Analysis of vowel and speaker dependencies of source harmonic magnitudes in consonant-vowel utterances
Authors: Iseli Markus , Shue Yen-Liang , Alwan Abeer
Published: October 2013

It is assumed that voice quality characteristics are mainly manifested in the glottal excitation signal. As [Holmberg et al., J. Speech Hear. Res. 38, 1212–1223 (1995)] showed, there is a correlation between low-frequency harmonic magnitudes of the glottal source spectrum and voice quality parameters. In this study, we assess the influence of vowel and speaker differences on the difference between the first and the second harmonic magnitudes, H1−H2. The improved harmonics correction formula introduced in [Iseli et al., Proceedings of ICASSP, Vol. 1 (2004), pp. 669–672] is used to estimate source harmonic magnitudes. H1−H2 is estimated for consonant-vowel utterances where the vowel is one of the three vowels /a,i,u/ and the consonant is one of the six plosives in American English /b,p,d,t,g,k/. Several repetitions of each of the utterances, spoken by two male and two female talkers, are analyzed. Other measurements, such as fundamental frequency, F0, and energy are estimated pitch synchronously. Results are compared to current literature findings. [Work supported by NSF.]
The effect of spatial frequency information in central and peripheral vision on natural gaze patterns and audiovisual speech perception
Authors: Buchan Julie N. , Wilson Amanda , Paré Martin , Munhall Kevin G.
Published: October 2013

It has been known for some time that visual information plays an important role in how we perceive speech. The present research examines how this visual information is processed in central and peripheral vision. The perception of visual images is carried out in the nervous system by a set of spatial frequency-tuned channels and the sensitivity to spatial resolution varies across the retina. The experiment was conducted using a gaze-contingent display system that records a person’s eye position and then displays different information to their peripheral and central vision. The amount of high spatial frequency information presented in the central and peripheral visual fields was manipulated and the effect on both audiovisual speech perception and natural gaze patterns was measured. Preliminary results show that when peripheral information is no longer adequate, gaze patterns become altered to gather important visual information. This suggests that information across the whole visual field influences audiovisual speech behavior.
An autonomous underwater vehicle towed hydrophone array for ocean acoustic measurements
Authors: Holmes Jason D. , Carey William M. , Lynch James F. , Newhall Arthur E. , Kukulya Amy
Published: October 2013

An autonomous underwater vehicle (AUV) with a towed hydrophone array (THA) can provide the capability of mobile-single-ship operation for both short-range single path and long range synthetic aperture experiments. A low noise towed array for an AUV (REMUS) has been developed to demonstrate the feasibility and utility of such measurements. Previous measurements of AUV radiated noise indicated levels that would limit measurements by hull arrays providing a rational for a THA. A small-diameter fluid-filled prototype hydrophone array was developed and tested to ensure adequate sensitivity and system noise levels. The digital recording system (DRS) consisted of mini-disc recorders with a band width of 20 kHz housed in a tube attached to the AUV. This combined system (REMUS, DRS, and THA) was used to conduct a proof of concept test in Dodge Pond. This paper presents the results that show, in the Sea State 0 noise field of Dodge Pond, array system self noise was less than the ambient and vehicle noise was manageable. The test included three pingers and a beacon sound source. The acoustic results were at a high signal-to-noise ratio and show the array tow stability and coherent processing capability. [Work supported by Boston University, Woods Hole, and ONR.]
Response pattern control in spite of failed array elements
Authors: Cox Henry , Lai Hung
Published: October 2013

Large arrays of many elements usually are shaded to achieve low sidelobes. However, in practice these arrays typically operate with some element failures that significantly degrade sidelobe performance. First, the effects of different numbers of failed elements on sidelobe levels are analyzed and illustrated with simulations. Statistics and bounds for sidelobe levels with failed elements are presented. The inability and limitations of conventional shading modifications to compensate for failed elements is discussed and illustrated. Missing elements give rise to large inter-element spacings that in turn result in grating effects that cannot be compensated for using modified shading weights. An adaptive compensation approach for failed elements is then presented. This involves narrowband interpolation from nearby elements to estimate the missing data prior to applying the original shading weights. Failures of both isolated and neighboring elements are considered. When there is a strong source present it is relatively easy to estimate its value on missing elements. But this is exactly the case of interest, when sidelobe levels are important. The adaptive interpolation approach provides good bearing response patterns so that strong signals are well isolated in bearing. Results are illustrated with large array simulations with different failure patterns and multiple strong sources.
Acoustics and sociolinguistics: Patterns of communication in hearing impairing classrooms
Authors: McKellin William , Shahin Kimary , Jamieson Janet , Hodgson Murray , Pichora-Fuller Kathleen
Published: October 2013

In elementary school classes, noise during student led activities is often taken as evidence of successful interaction and learning. In this complex social environment of elementary school classrooms, acquisition of complex language and social skills—the focus of activities in early education—is expected to take place in hearing-hostile environments. Communication and language processing in these contexts requires interactive strategies, discourse forms, and syntactic structures different from the educationally desired forms used in acoustically advantageous environments. Recordings were made of the interaction of groups of students in grades 1–3, 5, and 7 during collaborative group work in their regular classrooms. Each student wore microphones at the ear level and head-mounted video cameras. Each group as a whole was also audio- and videotaped and noise level readings were recorded. Analysis of the acoustical and phonological properties of language heard by each student has demonstrated that the language variety used in these noisy and reverberant settings is similar to that of individuals with hearing impairments. This paper reports similarities between the syntactic structures and pragmatic strategies used by hearing impaired children and normally hearing children in noisy contexts. [Work supported by Peter Wall Institute for Advanced Studies, University of British Columbia.]
Effects of road traffic and aircraft noise upon children’s academic attainments
Authors: Shield Bridget , Dockrell Julie , Vilatarsana Gael
Published: October 2013

The effects of environmental noise upon the academic performance of children aged 7 and 11 years in primary schools in London (UK) have been investigated. Noise surveys were carried out to measure levels of environmental noise during the school day outside 175 schools across London. The majority of the schools were in densely populated areas within 5 miles of central London, where road traffic was the dominant noise source. Thirty three of the schools were in a less densely populated area to the west of London near Heathrow Airport, and were subject to predominantly aircraft noise. The noise levels measured outside each school have been correlated with the results of standard tests in Reading, Writing, Mathematics, English, and Science, which are taken by all children aged 7 and 11 in England and Wales. Significant negative correlations were found between noise levels and many of the test scores, the correlations being stronger in the central London areas than in the schools around Heathrow. These results show that environmental noise has a detrimental effect upon childrens’ academic performance, the effect remaining apparent when data were corrected for socio-economic factors such as social deprivation.
Fisheries management applications of riverine hydroacoustics: 30 years’ experience with applied technology in the practical arena
Authors: Lapointe Michael F.
Published: October 2013

Some examples of the successes and challenges encountered by the Pacific Salmon Commission in the application of riverine hydroacoustics to fisheries management of Fraser River sockeye salmon are reviewed. Riverine hydroacoustics estimates have been an integral part of the fisheries data collected by the Pacific Salmon Commission for over 30 years. Real time estimates of fish passage provide intra-seasonal feedback on the progress toward escapement targets and information about changing total abundance levels. This information has allowed managers to adjust fisheries schedules and improved their ability to meet catch and escapement objectives. Despite these successes, application of technology has encountered a number of challenges including: (1) the interpretation of acoustics data in determining fish targets, (2) quantification of accuracy of hydroacoustic estimates in large rivers, (3) misperceptions about estimation methods by the public, and (4) inevitable comparisons with estimates from other sources and their effect on perceived accuracy of the hydroacoustic estimates. Lessons learned from the Pacific Salmon Commission experience are summarized with the objective of helping others engaged in the application of riverine acoustics technology to fisheries management problems.
Survey of dual frequency identification sonar (DIDSON) applications in fisheries assessment and behavioral studies
Authors: Belcher Edward O.
Published: October 2013

The Dual Frequency Identification Sonar (DIDSON) is a forward-looking sonar that operates in shallow riverine environments with rocky, uneven substrates and near concrete structures such as dams. This allows a number of fisheries applications in environments previously too hostile for reliable sonar operation. Currently 35 DIDSONs have been obtained by 16 groups to accomplish a variety of fish assessment and behavioral studies. This paper surveys the work of these groups and highlights novel assessments allowed by this new acoustic tool. The groups include Alaska Department of Fish and Game, U.S. Fish and Wildlife Service, NOAA, USGS, Bureau of Reclamation, California Department of Water Resources, Pacific Northwest National Laboratories, Nez Perce Tribal Fisheries, Puyallup Tribal Fisheries, Department of Fisheries and Oceans Canada, and Fisheries Engineering Japan. Assessments include: (1) Counting fish migrating up rivers of various sizes, bottom substrates, turbidity, and velocity; (2) Analysis of fish behavior at (A) prototype fish protection devices on dams, (B) irrigation intakes along muddy rivers, (C) intakes of trawl nets; and (3) Detection and measurement of redds in alluvial riverbeds. [Work for the survey supported by Sound Metrics Corp.]
Differentiating fish targets from non-fish targets using an imaging sonar and a conventional sonar: Dual frequency identification sonar (DIDSON) versus split-beam sonar
Authors: Xie Yunbo , Gray Andrew P. , Martens Fiona J.
Published: October 2013

A key requirement in applying acoustic techniques to estimating fish abundance is the removal of non-fish targets from the database. In a riverine environment, debris, entrained air bubbles, bottom objects are common ambient targets which can effectively scatter the probing sound from a fisheries sonar system, and cause strong echoes for the system. A conventional sonar system provides limited and highly simplified information for a detected target, which results in difficulty in separating fish from other targets. Recently developed DIDSON sonar utilizes imaging sonar technology to provide photo-quality images of underwater objects, making possible the visual interpretation of targets. A DIDSON system was deployed in the Fraser River at Mission, British Columbia during the salmon migration in 2004. Data were collected simultaneously from the DIDSON sonar and from a 200-kHz split-beam sonar. These data allow for comparisons of estimates of upstream salmon flux acquired concurrently by the imaging and the split-beam sonar systems.
Echoview software for tracking and counting fish detected with a dual frequency identification sonar (DIDSON) imaging sonar: A flexible approach to signal enhancement and object detection prior to target tracking
Authors: Higginbottom Ian
Published: October 2013

The data from the DIDSON (Dual frequency IDentification SONar) are of startling resolution, and show swimming fish in unprecedented detail. Although the fish objects are visually striking, object detection must be achieved in post processing and is a challenge when compared with conventional split beam systems. Data processing can be applied to automatically remove static objects and noise and to enhance the signal from moving objects in DIDSON data. Moving objects are then detected as targets within individual DIDSON frames and converted to X−Y−Z-time position data suitable for input to a tracking algorithm. The initial data manipulation for noise removal and object detection is achieved through the application of successive modular operators. The results of each operation can be viewed as a ‘‘virtual variable’’ enabling each step to be scrutinized and optimized by the operator. This modular approach to data manipulation, target detection, and fish tracking will enable the rapid development of new techniques and tools. It is a ‘‘future-proof’’ data processing solution.
Extracorporeal shock wave therapy in orthopedics, basic research, and clinical implications
Authors: Hausdorf Joerg , Jansson Volkmar , Maier Markus , Delius Michael
Published: October 2013

The molecular events following shock wave treatment of bone are widely unknown. Nevertheless patients with osteonecrosis and non unions are already treated partly successful with shock waves. Concerning the first indication, the question of the permeation of the shock wave into the bone was addressed. Therefore shockwaves were applied to porcine femoral heads and the intraosseous pressure was measured. A linear correlation of the pressure to the intraosseous distance was found. Approximately 50% of the pressure are still measurable 10 mm inside the femoral head. These findings should encourage continued shock wave research on this indication. Concerning the second indication (non union), osteoblasts were subjected to 250 or 500 shock waves at 25 kV. After 24, 48, and 72 h the levels of the bone and vascular growth factors bFGF, TGFbeta1, and VEGF were examined. After 24 h there was a significant increase in bFGF levels (p<0.05) with significant correlation (p<0.05) to the number of impulses. TGFbeta1, and VEGF showed no significant changes. This may be one piece in the cascade of new bone formation following shock wave treatment and may lead to a more specific application of shock waves in orthopedic surgery.
Cavitation, membrane transfer, and molecular response
Authors: Delius Michael , Adams Gerhard
Published: October 2013

Two topics are discussed in the following. First, red cell lysis and membrane transfer are primarily caused by cavitation since they are suppressed by excess hydrostatic pressure in the exposure vessel. It was additionally proposed that shock waves destroyed red blood cells directly at excess pressure above 10 MPa when cavitation was absent. When this was re-examined with a different pressure chamber with 10 and 20 MPa excess pressure, there was no increased red cell lysis and no direct action of shock waves was found. Second, it was long thought that the transfer of fluorescein dextran into cells was a good method to co-transfer another molecule. Dextran and the other substance had to be dissolved well in a defined molecular ratio and cells with a defined number of dextran molecules recovered by flow sorting contained also a defined number of the other molecule. The attempt to apply this approach for various numbers of molecules of a ribosome inactivating protein revealed, however, an inconclusive result.
Hair cell regeneration: Look to the future
Authors: Rubel Edwin W.
Published: October 2013

Less than 2 decades ago it was discovered that birds can regenerate hair cells in the auditory and vestibular parts of the inner ear after the native hair cells are destroyed by exposure to excessive noise or by mechanical trauma of aminoglycoside antibiotics. This discovery issued in a new era of hearing research—it suggested that some day it may be possible to actually restore hearing in people with congenital or acquired hearing loss due to the degeneration of sensory cells or supporting cells in the inner ear. Fifteen years is a very short time in the history of science. Consider the fact that we have actively sought chemical treatments to prevent or cure cancers for well over a half century and the ‘‘war on Cancer,’’ resulted in enormous public and private support. Progress has been great, and some forms of cancer can be treated with great success, but the overall 5-year survival rates have only risen from about 50% to 63%. Progress will continue and many more forms of cancer will be cured and prevented during the next half century. Similarly, during the first 15 years of hair cell regeneration research enormous progress has been made, and we now know that postnatal mammalian ears have the capacity to produce new hair cells. We are indeed a long way from restoring hearing through hair cell regeneration, but the future is pretty clear. I will review the progress of this field with an eye toward the future and what it means for treatments of today. In particular, I will address the potential cost versus benefits of bilateral implantation when applied to babies and young children.
Integrated building design
Authors: Sanguinetti Jennifer
Published: October 2013

For many years, building design has been a very linear process with owners speaking to architects who then design building shells that they pass along to sub-consultants who must fit their systems into the allotted spaces. While this process has some advantages, it provides little opportunity to optimize systems based on such factors as energy use or occupant comfort. This presentation will focus on the evolution and implications of integrated building design, a method that has provided greater opportunities for interaction between design disciplines and with building users early on in the design process. Integration has resulted in buildings that are more sustainable than typical buildings and that can respond better to the needs of the owner and users. Examples of the application of the process and the resulting buildings will be presented from the view of a design engineer with experience of both processes. Specifically, the potential contribution of an acoustical consultant in the integrated process will be explored.
Green buildings: Implications for acousticians
Authors: Noble Michael R.
Published: October 2013

This presentation will deal with the practical implications of green design protocols of the US Green Building Council on interior acoustics of buildings. Three areas of particular consequence to acousticians will be discussed. Ventilation Systems: reduced energy consumption goals dictate reliance on natural cooling and ventilation using ambient air when possible. The consequent large openings in the building envelope to bring fresh air into rooms, and similar sized openings to transfer the mixed air out, can severely compromise the noise isolation of the rooms concerned. Radiant Cooling: the heavy concrete floors of buildings can be used as a thermal flywheel to lessen the cooling load, which forces the concrete ceilings to be exposed to the occupied rooms for heat transfer, and strictly limits the application of acoustical absorption on the ceilings. This challenges the room acoustics design. Green Materials: the LEED protocols require the elimination of potentially harmful finishes, including fibrous materials which may impact air quality or contribute to health problems. Since the backbone of sound absorption is glass and mineral fibres, this further challenges provision of superior room acoustics. Examples and commentary will be provided based on current and recent projects.
Estimating biomass of densely populated fish schools from low-frequency acoustic scattering
Authors: Hahn Thomas R.
Published: October 2013

Fish schools of sufficient size and density can be efficient scatterers of low-frequency sound. This results from the large response of the fishes’ swim bladders to incoming acoustic waves at frequencies at or close to their natural resonance frequencies. Acoustically, these fish schools can be viewed as a single object with acoustic bulk parameters determined from the properties of the individual fish. This effective medium approach incorporates the acoustical coupling of all fish due to multiple scattering and works for a wide range of fish-sizes, -numbers and -densities. If the contrast between the effective medium and the surrounding water is large enough, resonant enhancement occurs. These modes of collective oscillations have been conclusively observed by many authors in the context of bubble clouds. A study of the analytical structure of the effective-medium scattering amplitude reveals simple expressions relating the center frequencies and widths of low-frequency collective resonances to the overall size and fish number density of the fish school. If observed, these resonances might yield stable information that together with the mean resonance frequency of individual fish could lead to simple and practicable estimates of the total school biomass.
Reorganization of pathological control functions of memory—A neural model for tissue healing by shock waves
Authors: Wess Othmar
Published: October 2013

Since 1980 shock waves have proven effective in the field of extracorporeal lithotripsy. More than 10 years ago shock waves were successfully applied for various indications such as chronic pain, non-unions and, recently, for angina pectoris. These fields do not profit from the disintegration power but from stimulating and healing effects of shock waves. Increased metabolism and neo-vascularization are reported after shock wave application. According to C. J. Wang, a biological cascade is initiated, starting with a stimulating effect of physical energy resulting in increased circulation and metabolism. Pathological memory of neural control patterns is considered the reason for different pathologies characterized by insufficient metabolism. This paper presents a neural model for reorganization of pathological reflex patterns. The model acts on associative memory functions of the brain based on modification of synaptic junctions. Accordingly, pathological memory effects of the autonomous nervous system are reorganized by repeated application of shock waves followed by development of normal reflex patterns. Physiologic control of muscle and vascular tone is followed by increased metabolism and tissue repair. The memory model may explain hyper-stimulation effects in pain therapy.
Investigations on stone fragmentation in different extracorporeal shock wave lithotripsy sound fields in vitro
Authors: Dreyer Thomas , Liebler Marko , Riedlinger Rainer
Published: October 2013

The mechanism of stone fragmentation in ESWL applications is still under investigation. Devices showing a wide focal area and comparably low focal pressure amplitudes have been reported to disintegrate stones more efficiently as current clinical devices with high amplitudes and small focal areas. From this the question is raised whether the underlying different physical mechanisms or treatment issues, like stone localization and movement, are responsible for these results. In this paper fragmentation experiments in vitro with different stone types (e.g., HMT and BegoStone, 15 mm diam.) under different sound fields are presented. A self focusing piezoelectric transducer with a small focal area and peak pressure amplitudes of up to 125 MPa is used. The number of pulses was counted until a complete fragmentation through a 2 mm wire mesh is reached. In order to simulate wide-focus low-pressure conditions, the stones were placed in the prefocal region. Fragmentation results are compared to the case of focal placement. Initial breakage occurs earlier in the prefocal region for the HMT stones, whereas complete fragmentation is reached significantly earlier in the focus for all stone types.