bluuebunny/crossref_metadata_2025 huggingface dataset:
Acoustic and other factors relating to the use of sound field systems in classrooms
Authors: Carey Anne , Shield Bridget , Dockrell Julie , Rigby Kate
Published: October 2013

A study has been made of thirty-five primary school classrooms which have Sound Field Systems (SFS) installed. Acoustic surveys of the classrooms have been undertaken and detailed observations made of the physical characteristics of each room such as its construction and design, plus any acoustic treatment. The positioning and type, e.g., column or separate speakers, of SFS installed were also noted. Details of the procedures for purchasing, installing, and maintaining the SFS were obtained where possible, together with information concerning training of teachers in their use. Results from these surveys suggest that in many cases SFS are installed in rooms where their performance may be compromised because of inadequate acoustic conditions. Additionally problems may arise due to inappropriate installation, choice of system, poor maintenance, or lack of training. The effectiveness of acoustic treatment such as absorption applied to ceilings and walls has also been investigated in a range of classrooms and its impact on the use of SFS considered.
Auditory evoked potential measurements in elasmobranchs
Authors: Casper Brandon , Mann David
Published: October 2013

Auditory evoked potentials (AEP) were first used to examine hearing in elasmobranchs by Corwin and Bullock in the late 1970s and early 1980s, marking the first time AEPs had been measured in fishes. Results of these experiments identified the regions of the ear and brain in which sound is processed, though no actual hearing thresholds were measured. Those initial experiments provided the ground work for future AEP experiments to measure fish hearing abilities in a manner that is much faster and more convenient than classical conditioning. Data will be presented on recent experiments in which AEPs were used to measure the hearing thresholds of two species of elasmobranchs: the nurse shark, Ginglymostoma cirratum, and the yellow stingray, Urobatis jamaicencis. Audiograms were analyzed and compared to previously published audiograms obtained using classical conditioning with results indicating that hearing thresholds were similar for the two methods. These data suggest that AEP testing is a viable option when measuring hearing in elasmobranchs and can increase the speed in which future hearing measurements can be obtained.
Single beam echosounding: Considerations of depth and seabed slope
Authors: Biffard Ben R. , Chapman N. Ross , Bloomer Steve F. , Preston Jon M.
Published: October 2013

The topic of depth compensation of single beam echo time series for seabed classification is fairly well studied. The effect of seabed slope has not been publicized. In applications for seabed classification, seabed slope is observed to be associated with classification inaccuracy and failure. In cases of higher slope, single beam bathymetry also becomes inaccurate. A survey of 2 fjords with extreme variation in slope is presented as a representative example and testing bed for investigating slope. The direct effect on seabed echoes is investigated and explained in reference to a simple model of beam-echo geometry. Survey bathymetry is compensated for slope; inaccuracies of up to 5% of depth are corrected, however bottom picking accuracy is diminished in areas of slope and cannot be improved. Surveys of a gas hydrate site and a river will also be presented as applications of these ideas. Early results from BORIS model studies of methods for compensation of slope and depth may also be presented.
A method for obtaining the geoacoustic properties of marine sediments using sound generated by aircraft
Authors: Giddens Eric M. , Buckingham Michael J.
Published: October 2013

A low-frequency geoacoustic inversion method has been developed for an isovelocity waveguide using light-aircraft as a source of sound. The high Doppler shift of the acoustic field facilitates the inversion, allowing directional information to be gathered by a single, omnidirectional receiver. The inversion method has been applied to simulations and to field experiments conducted in shallow water (14.4 m depth) off the coast of La Jolla. The inversion results will be discussed along with an error analysis using the Cramer-Rao Lower Bounds. [Work supported by ONR and the ARCS Foundation.]
Tissue-type imaging (TTI) based on ultrasonic spectral and clinical parameters for detecting, evaluating, and managing prostate cancer
Authors: Feleppa Ernest J. , Ketterling Jeffrey A. , Dasgupta Shreedevi , Kalisz Andrew , Ramachandran Sarayu , Porter Christopher R.
Published: October 2013

This study seeks to develop more-sensitive and -specific ultrasonic methods of imaging cancerous prostate tissue and thereby to improve means of guiding biopsies and planning, targeting, and monitoring treatment. Ultrasonic radio-frequency, echo-signal data, and clinical variables, e.g., PSA, voiding function, etc., during biopsy examinations were acquired. Spectra of the radio-frequency signals were computed in each biopsied region, and used to train neural networks; biopsy results served as the gold standard. A lookup table gave scores for cancer likelihood on a pixel-by-pixel basis from locally computed spectral-parameter and global clinical-parameter values. ROC curves used leave-one-patient- and leave-one-biopsy-out approaches to minimize classification bias. Resulting ROC-curve areas were 0.80±0.03 for neural-networks versus 0.66±0.03 for conventional classification. TTIs generated from data acquired pre-surgically showed tumors that were unrecognized in conventional images and during surgery. 3-D renderings of prostatectomy histology and TTIs showed encouraging correlations, which shows promise for improving the detection and management of prostate cancer, e.g., for biopsy guidance, planning dose-escalation and tissue-sparing options for radiation or cryotherapy, and assessing the effects of treatment. Combining MRS parameters with US spectral parameters appears capable of further improving prostate-cancer imaging. [Work supported by NIH.]
Injection-molded 1-3 piezocomposite sensor development: The last ten years
Authors: Benjamin Kim C.
Published: October 2013

The past ten years have seen several interesting demonstrations of 1-3 piezocomposite when used as the active component in sonar sensors. Initially considered receive only by most in the field, piezocomposite has evolved into a proven broadband transducer material with both receive and transmit capability. From large aperture single element calibration transducers, to parametric mode projectors, the material has surprised many experts with its power handling capability. Its polymer constituent provides an amazing degree of versatility by allowing the thermoforming and shaping of transducer substrates for packaging into todays undersea vehicles. This talk will review the last ten years of piezocomposite transducer and array development focusing on both the materials transmit behavior and fabrication benefits for future sonar applications. [Work supported by the U.S. Navy.]
Noise impact on community: A case study for power generation facility
Authors: Ma Yong , Chui Jonathan , Hertil Salem
Published: October 2013

Power generation plant will make noise impact on the surrounding communities and cause noise complaints from the residences. Noise mitigation treatment for plant is required to achieve the specified noise regulations. In this paper, a case study of the noise control design for a power generation facility is presented. Major noise sources included five engines and generators, five gas conditioning skids, five radiator coolers, and other accessory equipment. The acoustic modeling software Cadna/A was used to predict the noise contributions from sources and assess the noise impact on the nearby communities. During the acoustic modeling, alternative noise mitigation measures underwent two specific investigations before they were chosen as a noise solution recommendation. The first was to determine the technical feasibility of attenuating the source equipment. The second was to perform a cost benefit analysis, necessary to find the most cost-effective solution. For example, several acoustic wall and roof assemblies were entered into the acoustic model and the acoustic performance of the ventilation system was varied until we were able to achieve the most economical acoustic solution.
Acoustic observations of large earthquakes and associated phenomena
Authors: de Groot–Hedlin Catherine , McCormack David
Published: October 2013

Recent global events have renewed interest in acoustic observations of large earthquakes and associated phenomena such as landslides and tsunamis. In addition, the proliferation of global networks of atmospheric acoustic (infrasound) and hydroacoustic observing systems mean that signals from such events are captured in close to real-time more frequently and with better resolution than ever before. Such data provide a useful complement to more traditional seismological observations of such events. In this paper, recent acoustic and hydroacoustic observations from large earthquake events are presented. As well as the scientific insights provided by use of such monitoring systems, operational applications useful for hazard mitigation or hazard alerting are considered. Current plans to develop observing systems to perform systematic studies of areas susceptible to earthquake and tsunami hazard offshore western Canada, and the use of such proposed systems to make systematic studies of hydroacoustic signals from seismic events, underwater slumping and landslides are described.
Source localization of non-stationary acoustic data using time-frequency analysis
Authors: Stoughton Jack , Edmonson William
Published: October 2013

An improvement in temporal locality of the generalized cross-correlation (GCC) for angle of arrival (AOA) estimation can be achieved by employing 2-D cross-correlation of infrasonic sensor data transformed to its time-frequency (TF) representation. Intermediate to the AOA evaluation is the time delay between pairs of sensors. The signal class of interest includes far field sources which are partially coherent across the array, nonstationary, and wideband. In addition, signals can occur as multiple short bursts, for which TF representations may be more appropriate for time delay estimation. The GCC tends to smooth out such temporal energy bursts. Simulation and experimental results will demonstrate the improvement in using a TF-based GCC, using the Cohen class, over the classic GCC method. Comparative demonstration of the methods will be performed on data captured on an infrasonic sensor array located at NASA Langley Research Center (LaRC). The infrasonic data sources include Delta IV and Space Shuttle launches from Kennedy Space Center which belong to the stated signal class. Of interest is to apply this method to the AOA estimation of atmospheric turbulence. [Work supported by NASA LaRC Creativity and Innovation project: Infrasonic Detection of Clear Air Turbulence and Severe Storms.]
So/ren Buus’ contribution to speech intelligibility prediction
Authors: Müsch Hannes , Florentine Mary
Published: October 2013

In addition to his work in psychoacoustics, So/ren Buus also contributed to the field of speech intelligibility prediction by developing a model that predicts the results of speech recognition tests [H. Müsch and S. Buus, J. Acoust. Soc. Am. 109, 2896–2909 (2001)]. The model was successful in test conditions that are outside the scope of the Articulation Index. It builds on Green and Birdsall’s concept of describing a speech recognition task as selecting one of several response alternatives [in D. Green and J. Swets, Signal Detection Theory (1966), pp. 609–619], and on Durlach et al.’s model for discriminating broadband sounds [J. Acoust. Soc. Am. 80, 63–72 (1986)]. Experimental evidence suggests that listeners can extract redundant, independent, or synergistic information from spectrally distinct speech bands. One of the main accomplishments of the model is to reflect this ability. The model also provides for a measure of linguistic entropy to enter the intelligibility prediction. Recent model development has focused on investigating whether this measure, the cognitive noise, can account for the effects of semantic and syntactic context. This presentation will review the model and present new model predictions. [Work supported by NIH grant R01DC00187.]
Non-contact mode excitation of small structures in air using ultrasound radiation force
Authors: Huber Thomas M. , Purdham John C. , Fatemi Mostafa , Kinnick Randall R. , Greenleaf James F.
Published: October 2013

With the advent of MEMS, modal analysis of small structures is increasingly important. However, conventional excitation techniques normally require contact, which may not be feasible for small objects. We present a non-contact method that uses interference of ultrasound frequencies in air to produce low-frequency excitation of structures. Objects studied included hard-drive HGA suspensions and MEMS devices. The vibration induced by the ultrasound radiation force was varied in a wide range from 0 Hz to 50 kHz. Object motion was detected using a laser vibrometer; measured frequencies agreed with expected values. Also demonstrated was the unique capability to selectively enhance or suppress modes independently. For example, the ratio of the vibrational amplitudes of the 175 Hz first-bending and 1.33 kHz torsional modes of a small cantilever could be changed from in excess of 10:1 to less than 1:10 by shifting the ultrasound modulation phase 90 degrees. Similar changes were obtained for a 3 mm square MEMS mirror in the ratios of vibration amplitude around its two separate axes. Torsional modes of a hard-drive suspension could be selectively enhanced by over a factor of two by moving the ultrasound focus point from near the center to near the edge of the suspension.
Non-intrusive ground-contacting vibrometer for acoustic/ seismic landmine detection
Authors: Martin James S. , Larson Gregg D. , Scott Waymond R.
Published: October 2013

The detection of buried landmines using seismic waves and full wave-field measurements has been demonstrated. The technique requires a sensor that is non-intrusive with sufficient fidelity, reproducibility, and noise immunity for imaging processes. This has been accomplished in the past with non-contact techniques. For reasons of cost and scalability in large arrays, ground-contacting sensors are currently of interest as an alternative to these. A ground-contacting sensor configuration was studied in which an accelerometer was coupled to the ground through a viscoelastic layer with a bias force provided by a soft coil spring. This sensor was found to meet the noise, fidelity, and reproducibility requirements of a seismic landmine detection system operating in a laboratory experimental model. The fidelity of this sensor was found to vary with the bias force because of the nonlinear stiffness of the soil surrogate in the model. This dependence was sufficiently weak that no feedback of the bias force was necessary to reproducibly couple the sensor over a flat surface. The sensor offers the potential benefit of information that was not available from non-contact measurements regarding the in-plane motion of the soil surface. This data may provide additional cues for the detection of buried mines. [Work supported by ONR.]
Acoustic characteristics of Korean stops in Korean child-directed speech
Authors: Kim Minjung , Stoel-Gammon Carol
Published: October 2013

A variety of cross-linguistic studies have documented that the acoustic properties of speech addressed to young children include exaggeration of pitch contours and acoustically salient features of phonetic units. It has been suggested that phonetic modifications of child-directed speech facilitate young children’s speech perception by providing detailed phonetic information about the target word. While there are several studies reporting vowel modifications in speech to infants (i.e., hyper-articulated vowels), there has been relatively little research about consonant modifications in speech to young children (except for VOT). The present study examines acoustic properties of Korean stops in Korean mothers’ speech to their children aged 29 to 38 months (N=6). Korean tense, lax, and aspirated stops are all voiceless in word-initial position, and are perceptually differentiated by several acoustic parameters including VOT, f0 of the following vowel, and the amplitude difference of the first and second harmonics at the voice onset of the following vowel. This study compares values of these parameters in Korean motherese to those in speech to adult Koreans from same speakers. Results focus on the acoustic properties of Korean stops in child-directed speech and how they are modified to help Korean young children learn the three-way phonetic contrast.
Pacific northwest vowels: A Seattle neighborhood dialect study
Authors: Ingle Jennifer K. , Wright Richard , Wassink Alicia
Published: October 2013

According to current literature a large region encompassing nearly the entire west half of the U.S. belongs to one dialect region referred to as Western, which furthermore, according to Labov et al., ‘‘... has developed a characteristic but not unique phonology.’’ [http://www.ling.upenn.edu/phono—atlas/NationalMap/NationalMap.html] This paper will describe the vowel space of a set of Pacific Northwest American English speakers native to the Ballard neighborhood of Seattle, Wash. based on the acoustical analysis of high-quality Marantz CDR 300 recordings. Characteristics, such as low back merger and [u] fronting will be compared to findings by other studies. It is hoped that these recordings will contribute to a growing number of corpora of North American English dialects. All participants were born in Seattle and began their residence in Ballard between ages 0–8. They were recorded in two styles of speech: individually reading repetitions of a word list containing one token each of 10 vowels within carrier phrases, and in casual conversation for 40 min with a partner matched in age, gender, and social mobility. The goal was to create a compatible data set for comparison with current acoustic studies. F1 and F2 and vowel duration from LPC spectral analysis will be presented.
Identifying native Cantonese stops: Implication for native speakers perception
Authors: Gao Man
Published: October 2013

A series of perception tasks were conducted to probe Cantonese speakers ability to perceive their languages syllable-final unreleased stops. Stimuli consisted of minimal sets of monosyllabic words with contrasting codas produced by a speaker of Hong Kong Cantonese. Twelve Guangzhou Cantonese speakers and five Hong Kong Cantonese speakers performed the perceptual tasks which included: matching stimuli with the corresponding orthographic character; AXB discrimination; and identifying word-final [p], [t], [k] and vowel explicitly. Five native speakers of Mandarin (where final stops are not allowed) also took the AXB and identification tasks. Both Guangzhou and Hong Kong speakers scored high in matching task: 93 and 96 percent correct respectively; for AXB task, subjects from Hong Kong (93%) did slightly better than those from Guangzhou (85%), and Mandarin speakers scored the lowest (78%). The most interesting findings were in the identification tasks, although subjects from Hong Kong scored the highest (82%), the accuracy of Guangzhou Cantonese speakers was surprisingly low (49%)—even worse than Mandarin speakers (69%). Explanation for the observed discrepancy between Guangzhou and Hong Kong subjects will be discussed with respect to their different language education as well as their distinct language experience. Implications for phonological awareness will also be discussed.
Adapting a truly nonlinear filter to the ocean acoustic inverse problem
Authors: Ganse Andrew A. , Odom Robert I.
Published: October 2013

Nonlinear inverse problems including the ocean acoustic problem have been solved by Monte Carlo, locally-linear, and filter based techniques such as the Extended Kalman Filter (EKF). While these techniques do provide statistical information about the solution (e.g., mean and variance), each suffers from inherent limitations in their approach to nonlinear problems. Monte Carlo techniques are expensive to compute and do not contribute to intuitive interpretation of a problem, and locally-linear techniques (including the EKF) are limited by the multimodal objective landscape of nonlinear problems. A truly nonlinear filter, based on recent work in nonlinear tracking, estimates state information for a nonlinear problem in continual measurement updates and is adapted to solving nonlinear inverse problems. Additional terms derived from the system’s state PDF are added to the mean and covariance of the solution to address the nonlinearities of the problem, and overall the technique offers improved performance in nonlinear inversion. [Work supported by ONR.]
A neural network for mode space source depth estimation
Authors: Lee William , Lee Yung
Published: October 2013

A great deal of research in mode space source localization processing exists. One technique proposed by Shang performs mode filtering of the observed pressure field on a vertical line array, using the calculated mode amplitude distributions and phase differences to estimate source location. Ozard et al. proposed a feed forward neural network using input vectors of mode energy distribution for source localization, a dedicated neuron for each possible source location was employed in their study. Instead of employing a dedicated neuron for each possible search location, the interest of this study is to determine an efficient setup of neurons to properly sample the search space. In MATLAB neural network toolbox, the self-organizing-map function learns to classify input vectors according to how they are grouped in the input space, specifically their distribution and topology. We used this function to examine how input vectors of mode energy distribution for signals at different depths are grouped to determine the sampling grids of the search space in depth. We also compared the neural network performance using input vectors of mode amplitude distribution with those using input vectors of mode energy distribution.
ClassTalk system for predicting and auralizing speech in noise with reverberation in classrooms
Authors: Hodgson Murray , Graves Daniel
Published: October 2013

This paper discusses and demonstrates the ClassTalk system for predicting, visualizing and auralizing speech in noise with reverberation in classrooms. The classroom can contain a speech-reinforcement system (SRS). Male or female speech sources, SRS loudspeakers and overhead, slide or digital projectors, or ventilation-noise sources, can have four output levels. Empirical models are used to predict speech and noise levels, and Early Decay Times, from which Speech Transmission Index (STI) and Speech Intelligibility (SI) are calculated. ClassTalk visualizes the floor-plan, speech- and noise-source positions, and the receiver position. The user can walk through the room at will. In real time five quantities, background-noise level, speech level, signal-to-noise difference, STI and SI, are displayed along with occupied and unoccupied reverberation times. The sound module auralizes male or female speech mixed with the relevant noise signals, with predicted, frequency-varying reverberation superimposed using MaxxVerb. Technical issues related to the development of the sound module are discussed. The potential of the systems auralization module for demonstrating the effects of the acoustical environment and its control on speech is discussed and demonstrated.
Sound localization and auditory response capabilities in round goby (Neogobius melanostomus)
Authors: Rollo Audrey K. , Higgs Dennis M.
Published: October 2013

A fundamental role in vertebrate auditory systems is determining the direction of a sound source. While fish show directional responses to sound, sound localization remains in dispute. The species used in the current study, Neogobius melanostomus (round goby) uses sound in reproductive contexts, with both male and female gobies showing directed movement towards a calling male. The two-choice laboratory experiment was used (active versus quiet speaker) to analyze behavior of gobies in response to sound stimuli. When conspecific male spawning sounds were played, gobies moved in a direct path to the active speaker, suggesting true localization to sound. Of the animals that responded to conspecific sounds, 85% of the females and 66% of the males moved directly to the sound source. Auditory playback of natural and synthetic sounds showed differential behavioral specificity. Of gobies that responded, 89% were attracted to the speaker playing Padogobius martensii sounds, 87% to 100 Hz tone, 62% to white noise, and 56% to Gobius niger sounds. Swimming speed, as well as mean path angle to the speaker, will be presented during the presentation. Results suggest a strong localization of the round goby to a sound source, with some differential sound specificity.
Emotional learning modulates the rats sensitivity to transient changes in correlation between sounds
Authors: Huang Juan , Li Liang , Yang Zhigang , Ping Junli , Liu Xian , Chen Yixin , Wu Xihong
Published: October 2013

Humans are sensitive to small discrepancies between two sounds, and can detect a transient change in sound correlation. Here, prepulse inhibition of the startle reflex was used to examine rats sensitivity to transient changes in correlation between two correlated broadband noises, which were delivered by two spatially separated loudspeakers. The results show that either an uncorrelated noise fragment (UCNF, a drop of inter-sound correlation from 1.00 to 0 and then return to 1.00) or an anti-phase noise fragment (APNF, a drop of inter-sound correlation from 1.00 to −1.00 and then return to 1.00) could be detected by rats, since each of the changes in correlation could act as a prepulse stimulus to inhibit the startle reflex. The duration threshold for detecting the APNF was much lower than that for the UCNF. The detection of each of the changes in correlation was improved either by prolonged testing or by temporally pairing the UCNF or APNF with footshock. Thus similar to humans, rats also have the sensitivity to a sudden change in inter-sound correlation. Moreover, an increase of the sensitivity can be induced in rats either by repeated exposure to the change in correlation or by emotional learning.
The role of tragus on echolocating bat, Eptesicus fuscus
Authors: Chiu Chen , Moss Cynthia
Published: October 2013

Echolocating bats produce ultrasonic vocal signals and utilize the returning echoes to detect, localize and track prey, and also to avoid obstacles. The pinna and tragus, two major components of the bats external ears, play important roles in filtering returning echoes. The tragus is generally believed to play a role in vertical sound localization. The purpose of this study is to further examine how manipulation of the tragus affects a free-flying bat’s prey capture and obstacle avoidance behavior. The first part of this study involved a prey capture experiment, and the bat was trained to catch the tethered mealworms in a large room. The second experiment involved obstacle avoidance, and the bat’s task was to fly through the largest opening from a horizontal wire array without touching the wires. In both experiments, the bat performed the tasks under three different conditions: with intact tragus, tragus-deflection and recovery from tragus-deflection. Significantly lower performance was observed in both experiments when tragi were glued down. However, the bat adjusted quickly and returned to baseline performance a few days after the manipulation. The results suggest that tragus-deflection does have effects on both the prey capture and obstacle avoidance behavior. [Work supported by NSF.]
Real-time observations and predictions of scour burial at the Martha’s Vineyard Coastal Observatory
Authors: Richardson Michael D. , Traykovski Peter , Trembanis Arthur C. , Friedrichs Carl T.
Published: October 2013

Mine burial by scour was measured in real-time using cylindrical instrumented mines and rotary and two-axis pencil beam sonar. Two mines and the sonar were connected to a shore-based facility at the Martha’s Vineyard Coastal Observatory. Data on mine movement (heading, pitch, and roll), scour pit geometry, percent burial, and environmental processes responsible for scour burial including significant wave height, period, and tidal height were analyzed daily and presented on a mine burial web site. Sonar images show scour pits developing around the mines in response to storm generated significant wave heights greater than 2.0 m. Mines pitch, change heading as they roll into scour pits. A comparison of the observed mine burial and real-time predictions using a modified version of the Whitehouse equations for wave-induced scour model exhibited good agreement suggesting mine burial by scour in similar sandy environments is predictable from bathymetry, sediment type, and measured or predicted surface wave conditions. The Coastal Observatory at Martha’s Vineyard provided a unique opportunity for real-time data collection and analysis of both sediment transport events and seafloor-object interactions during storms. [Work supported by ONR.]
Remote acoustic observations from a real-time observing system of the response of a shallow coastal embayment to hurricane forcing
Authors: Schillinger Douglas J. , Hay Alex E.
Published: October 2013

Results are presented from the acoustic remote sensing component of Dalhousie University’s interdisciplinary Coastal Ocean Observatory in Lunenburg Bay, Nova Scotia, operational since June 2002 (www.cmep.ca/bay). Remote acoustic measurements of water column velocity and backscatter are made from bottom-mounted instruments hard-wired to surface buoys. The data are telemetered in near real-time to a shore station via wireless Ethernet, and to Dalhousie over the Internet. The fixed-point measurements from the bottom pods are augmented by a vessel-mounted profiling system, and by opportunistic deployments of internally-recording instruments. Highlights from the first three years of the observing system operation will be presented, including sediment suspension from the seabed and bubble penetration from the surface during Hurricane Juan.
Delivery of anticancer drugs and antibodies into cells using ultrasound
Authors: Wu Junru , Pepe Jason , Rincon Mercedes
Published: October 2013

It has been shown experimentally in cell suspensions that pulsed ultrasound (2.0 MHz) could be used to deliver an anti-cancer drug (Adriamycin hydrochloride) into Jurkat lymphocytes and antibodies (goat anti rabbit IgG and anti mouse IgD) into human peripheral blood mononuclear (PBMC) cells and Jurkat lymphocytes assisted by encapsulated microbubbles (Optison). When Adriamycin hydrochloride (ADR) was delivered, the delivery efficiency reached 4.80% and control baseline (no ultrasound and no ADR) was 0.17%. When anti-rabbit IgD was delivered, the efficiencies were 34.90% (control baseline was 1.33%) and 32.50% (control baseline was 1.66%) respectively for Jurkat cells and PBMC. When goat anti rabbit IgG was delivered, the efficiencies were 78.60% (control baseline was 1.60%) and 57.50% (control baseline was 11.30%) respectively for Jurkat cells and PBMC.
Modeling of initial bubble growth rates during high-intensity focused ultrasound
Authors: Kreider Wayne , Bailey Michael R. , Crum Lawrence A.
Published: October 2013

In therapeutic applications of biomedical ultrasound, it is important to understand the behavior of cavitation bubbles. For applications that use high-intensity focused ultrasound (HIFU), both large negative acoustic pressures and heating can independently lead to bubble formation. Although neglected previously, heating during HIFU is expected to affect the growth and dissolution of bubbles by both raising the vapor pressure and promoting outgassing from gas-saturated tissues. Herein, the dynamics of a single, spherical bubble in water have been modeled using the Gilmore equation closed with an energy balance on bubble contents for calculation of pressures inside the bubble. Moreover, heat and mass transfer at the bubble wall are incorporated using the Eller-Flynn zeroth-order approximation for gas diffusion, an estimation of non-equilibrium phase change based on the kinetic theory of gases, and assumed shapes for the spatial temperature distribution in the surrounding liquid [Yasui, J. Phys. Soc. Jpn. 65, 2830–2840 (1996)]. This model allows explicit coupling of the ambient heating during HIFU to the thermodynamic state of an oscillating bubble and is currently being used to explore the growth rates of initially small, undetectable bubbles exposed to various HIFU treatment protocols. [Work supported by NIH T32-EB-001650, NIH DK43881, and NSBRI SMS00203.]
Ultrasound contrast agents for bleeding detection and acoustic hemostasis
Authors: Zderic Vesna , Luo Wenbo , Brayman Andrew , Crum Lawrence , Vaezy Shahram
Published: October 2013

Objective: To investigate the application of ultrasound contrast agents (UCA) in improving both therapeutic and diagnostic aspects of ultrasound-guided High Intensity Focused Ultrasound (HIFU) therapy. Methods: Incisions (3 cm long, 0.5 cm deep) were made in rabbit livers (in anterior surface for HIFU treatment, or posterior surface for bleeding detection). UCA Optison (∼0.1 ml/kg) was injected into mesenteric vein or ear vein. A HIFU applicator (5.5 MHz, 6400 W/cm2) was scanned manually over the incision until hemostasis was achieved. Occult bleeding was monitored with Doppler ultrasound. Results: The presence of Optison produced 37% reduction in hemostasis times normalized to initial bleeding rates. Gross and histological observations showed similar appearance of HIFU lesions produced in the presence of Optison and control HIFU lesions. The temperature reached 100°C in both HIFU only and HIFU+UCA treatments. Tension strength of hemostatic liver incisions was 0.9±0.5 N. Almost no bleeding could be detected before Optison injection. First appearance of contrast enhancement localized at the bleeding site was 15 s after Optison injection, and lasted for ∼50 s. Conclusion: The presence of UCA during HIFU treatment of liver incisions resulted in shortening of HIFU application times and better visualization of bleeding sites.
Microrhythmic characteristics of musical instrument initial transients
Authors: Bader Rolf
Published: October 2013

A microrhythmic analysis of initial transients of the violin, the guitar, the saxophone, the clarinet, and percussion instruments has been performed. They show characteristic patterns between instrument families, concerning the derivation of microrhythmic intervals within the tonal frequency range compared to psychoacoustic discrimination tasks by listeners. Microrhythm here is defined as the temporal distance between two amplitude peaks. As initial transients are a crucial part of the sound in terms of identification of instruments and the initial is just in the range of the second integration time of the ear, where frequency components can just be identified, these microrhythmic patterns could be a possibility for listeners to identify the instrument families. This is because microrhythmic intervals are instantaneously present and do not need an integration time span.
Signal-to-background-ratio preferences of normal-hearing listeners as a function of music
Authors: Barrett Jillian G.
Published: October 2013

The primary purpose of speech is to convey a message. Many factors affect the listener’s overall reception, several of which have little to do with the linguistic content itself, but rather with the delivery (e.g., prosody, intonation patterns, pragmatics, paralinguistic cues). Music, however, may convey a message either with or without linguistic content. In instances in which music has lyrics, one cannot assume verbal content will take precedence over sonic properties. Lyric emphasis over other aspects of music cannot be assumed. Singing introduces distortion of the vowel-consonant temporal ratio of speech, emphasizing vowels and de-emphasizing consonants. The phonemic production alterations of singing make it difficult for even those with normal hearing to understand the singer. This investigation was designed to identify singer-to-background-ratio (SBR) prefer- ences for normal hearing adult listeners (as opposed to SBR levels maxi-mizing speech discrimination ability). Stimuli were derived from three different original songs, each produced in two different genres and sung by six different singers. Singer and genre were the two primary contributors to significant differences in SBR preferences, though results clearly indicate genre, style and singer interact in different combinations for each song, each singer, and for each subject in an unpredictable manner.
Effectiveness of the hearing conservation program: Change in hearing threshold shift incidence among industrial workers, 1978 to 2003
Authors: Davies Hugh
Published: October 2013

Hearing conservation programs (HCP) are widely employed in preventing noise-induced hearing loss, but studies of their effectiveness have been rare. The impact of the implementation of hearing conservation programs was assessed in a large group of highly noise-exposed blue-collar workers by investigating time-trends in hearing-threshold shift incidence. Serial annual audiograms for employees of 14 British Columbia lumber mills for the period 1978 to 2003 were obtained from local regulatory-agency archives. Audiograms and concomitant otological medical histories were linked to subjects’ work histories and noise exposure data. Multivariable Cox proportional hazard models were used to model the incidence of hearing threshold shift while controlling for age, baseline level of hearing loss, and other potential confounders. A total of 109257 audiograms were associated with 10590 subjects. Mean noise exposure in this group was 91.4 dBA(A). Mean interval between hearing tests was 566 days and mean age at first threshold shift was 44. Forty-six percent of subjects had at least one OSHA significant threshold shift during follow up. Preliminary analyses indicated a trend toward lower incidence of threshold shifts over the study period, with incidence in 5 approximately equal 5-year periods from 1978 to 2003 being 3.2%, 6.6%, 4.9%, 4.3% and 2.4%, respectively.
Alternative noise exposure metrics among construction workers
Authors: Seixas Noah , Neitzel Rick , Sheppard Lianne , Goldman Bryan
Published: October 2013

There continues to be some uncertainty in the choice of noise exposure metrics for assessing the risk of hearing damage. In particular, the Leq, based on a 3 dB exchange rate (ER) and the Lavg, which uses a 5 dB ER are both in use, as are various metrics representing exposure peaks. This paper presents an analysis of a large database of noise exposures among construction workers, comparing several noise metrics, and their application to a cohort of construction workers, followed audiometrically over a three year period. Metrics examined were the Lavg, Leq, and Lmax, expressing average levels. Two novel metrics were derived from these monitored metrics, Leq/Lavg, and Lmax/Leq, as measures of exposure variability and peakiness. A total of 730 workshifts, including data on 361 492 min of exposure to workers in 9 trades were examined. Correlations between average metrics (Leq, Lavg, Lmax) are generally very high, while the variability metrics are poorly correlated with average levels and with each other, indicating that they characterize different aspects of exposure. The task-specific estimates of individual exposure, using the various metrics, were applied to the cohorts work history and their effects on changes in hearing were assessed.
Special issues in hearing loss prevention in the Canadian military environment
Authors: Giguère Christian , Laroche Chantal
Published: October 2013

Noise can be particularly noxious to hearing in the military. The personnel regularly face a wide range of noise-hazardous situations, many of which are seldom encountered in other work environments. High noise levels are associated with the operation of small arms and large caliber weapons, combat vehicles, aircrafts, ships and vessels, and industrial equipment. This can induce permanent and temporary hearing loss, compromise speech communication, interfere with the detection and localization of sound sources and warning sounds and thus, can jeopardize life or safety of the personnel. This paper will review the essential elements of a hearing loss prevention program proposed for the Canadian Armed Forces. The ultimate goal is to preserve hearing health as well as all hearing abilities necessary for effective operations. The program has been designed to meet the noise measurement and hazard investigation procedures, limits on noise exposure, use of hearing protection and other regulatory measures contained in the Canadian Occupational Health and Safety (COHS) Regulations (Part VII: Levels of Sound), while addressing the particular nature of the military environment. The paper will focus on issues that are not typically found in other occupational environments (variable work schedules, excessive impulse noise, extended exposures, communication devices).
The combined effect of noise and carbon monoxide on hearing thresholds of exposed workers
Authors: Lacerda Adriana , Leroux Tony , Gagn Jean-Pierre
Published: October 2013

Animal models have been used to demonstrate the potentiation of noise-induced hearing loss (NIHL) by carbon monoxide. It has been shown that the addition of carbon monoxide to otherwise safe noise exposure levels produces significant NIHL in rats. However, the effects of chronic exposure to low level of carbon monoxide in a noisy work environment are still unknown. The aim of this study was to compare the hearing thresholds of a group of workers exposed to noise and carbon monoxide (Group 1) to another group of workers where carbon monoxide exposure is absent or negligible (Group 2). The analysis was based on 9396 audiograms collected by the Quebec National Public Health Institute between 1983 and 1996. The results show significantly poorer hearing thresholds at high frequencies (3, 4, and 6 kHz) for the carbon monoxide exposed group (p<0.001). The potentiation effect also varied according to years of exposure in work place; a larger effect is observed for workers with between 15 to 20 years of exposure (p<0.001). This study provides the first demonstration of a potentiation effect of NIHL by carbon monoxide in humans.
Derivation of an analytic expression for the error associated with the noise reduction rating
Authors: Murphy William J.
Published: October 2013

Hearing protection devices are assessed using the Real Ear Attenuation at Threshold (REAT) measurement procedure for the purpose of estimating the amount of noise reduction provided when worn by a subject. The rating number provided on the protector label is a function of the mean and standard deviation of the REAT results achieved by the test subjects. If a group of subjects have a large variance, then it follows that the certainty of the rating should be correspondingly lower. No estimate of the error of a protector’s rating is given by existing standards or regulations. Propagation of errors was applied to the Noise Reduction Rating to develop an analytic expression for the hearing protector rating error term. Comparison of the analytic expression for the error to the standard deviation estimated from Monte Carlo simulation of subject attenuations yielded a linear relationship across several protector types and assumptions for the variance of the attenuations.
The influence of target-masker similarity in a three-talker diotic listening task
Authors: Iyer Nandini , Brungart Douglas
Published: October 2013

In diotic cocktail-party listening tasks, performance decreases dramatically when the number of talkers increases from two (one target and one masker) to three (one target and two maskers). In this experiment, listeners were asked to extract information from a Coordinate Response Measure (CRM) target phrase that was masked by one or two interfering utterances. The maskers were either semantically similar to the target (i.e., CRM phrases with different call signs than the target phrase) or semantically different from the target (time-reversed, contextually dissimilar, or in a different language than the target phrase). The two-talker results showed that performance was much worse when the interfering phrase was semantically similar to the target than when it was semantically different. However, given that one interfering talker was similar to the target, the contextual similarity of the second interfering talker had very little effect on performance; in other words, target intelligibility in the presence of two CRM maskers was no worse than with one CRM masker and one time-reversed or foreign-language masker. These results suggest that the disruption of speech segregation caused by the addition of a second interfering talker cannot be explained solely by contextual similarity between the target and masking speech.
Transmission line analysis of cylindrical shells with exterior fluid loading
Authors: Stokes Ann , Corrado Charles , Garrelick Joel
Published: October 2013

The Wave Transmission Line (WTL) numerical modeling formulation has been developed to understand and efficiently compute the transmission of acoustic energy through fluid-filled elastic shells. The structural systems are represented as a sequence of components and discontinuities connected with straight duct sections. The motion of straight segments is described in terms of amplitudes of freely traveling, left-and-right propagating waves. Recent work in Rational Function Approximation (RFA) of exterior fluid loading permits this approach to be extended to cylindrical structures with interior and exterior fluid loading. The resulting approach is more computationally efficient than conventional finite element approaches. This paper describes development of systems of transmission line equations for segmented cylindrical shells with exterior and interior fluid loading.
Pitch accent timing in Chickasaw
Authors: Gordon Matthew K.
Published: October 2013

This paper examines the temporal realization of pitch accents in Chickasaw, a Muskogean language of Oklahoma. Questions in Chickasaw have a Lat their right edge preceded by a H* pitch accent that docks on one of the final three syllables of the last word in the Intonational Phrase: on a final CVV, otherwise on a heavy (CVV or CVC) penult, otherwise on the antepenult. Three speakers of Chickasaw were recorded uttering a list of words varying in the location of the pitch accent and the type of syllable carrying the pitch accent. Results indicate a tendency to realize the pitch accent relatively late in non-final pitch accented syllables (during the last 25 and during the coda consonant following a short vowel). However, final accented syllables realize the pitch accent early (within the first 20 vowel) and also display substantial vowel lengthening (by over 50 vowels in the penult or antepenult). These results suggest that pressure to avoid tonal crowding between the pitch accent and boundary tone overrides the late realization of pitch accents characteristic of positions in which crowding is less of an issue.