bluuebunny/crossref_metadata_2025 huggingface dataset:
Transition to a 1‐year deferral for male blood donors who report sexual contact with men: staff perspectives at one blood collection organization
Authors: Hughes Shana D. , Custer Brian , Laborde Nicole , Sheon Nicolas
Published: April 2018

BACKGROUND

Front‐line staff at blood collection organizations (BCOs) play important roles in keeping the blood supply safe, yet research on their professional practice and perspectives on training needs is sparse. This qualitative study explored these topics with regard to the then‐impending change in donor eligibility for men reporting sex with another man (MSM).

STUDY DESIGN AND METHODS

Semistructured, individual interviews with BCO staff (n = 13) in Northern California covered experiences of and opinions on indefinite deferral, the revised 1‐year deferral, and anticipated potential challenges arising from the new policy. Transcripts were thematically coded, using deductive and inductive approaches. Analysis identified recurrent and divergent themes.

RESULTS

Interviewees reported strong values of professionalism and respect for donors and supported the change to a 1‐year deferral for MSM donors. Nonetheless, nearly all voiced the need for more in‐depth training to maximize the likelihood of successful implementation. Specific recommendations included the use of role‐play, provision of science‐based talking points or FAQs, and empathy for donors and staff.

CONCLUSION

More than the usual training may be required to help BCO staff feel prepared to educate the public about changes to MSM‐related deferrals and communicate effectively with donors about potentially deferrable behavior. Overall, these findings suggest that before future policy changes, BCO staff's opinions about and role in implementing new donor eligibility screening procedures merit consideration.
Conductive hearing loss in four dogs associated with the use of ointment‐based otic medications
Authors: Cole Lynette K. , Rajala‐Schultz Päivi. J. , Lorch Gwendolen
Published: April 2018

Background

Hearing loss (HL) is classified as conductive when sound transmission is compromised in the ear canal or middle ear, or sensorineural when there is an abnormality of the receptor cells of the cochlea or auditory pathway. Hearing in dogs is evaluated using the brainstem auditory evoked response (BAER) test.

Hypothesis/Objectives

Our objective was to characterize BAER findings pre‐ and post‐ear flushing in four dogs with acute HL following application of an ointment‐based otic medication containing betamethasone, clotrimazole and gentamicin in a mineral oil‐based system containing a plasticized hydrocarbon gel.

Animals

Dogs, ranging from 9 to 11 years old, that had been treated with the otic medication for one to three weeks prior to hearing loss and on otoscopic examination had evidence of medication in the horizontal ear canals.

Methods

Dogs were anaesthetized for an ear flush to remove the medication from the ear canals. Hearing was assessed using BAER testing, measurements were initiated with 116 decibel peak equivalent sound pressure level (dBpeSPL) click. Estimated threshold was defined as the lowest intensity in dB in which wave V was still present.

Results

Post‐ear flush the estimated threshold improved in both ears of all dogs (mean 22.3 dB; range 13–41 dB), confirming conductive HL due to the otic medication. All owners noted an improvement in their dog's hearing post‐ear flush, validating the BAER findings.

Conclusions and clinical importance

These results emphasize the importance of an ear flush to remove otic medications in dogs that experience acute HL, to determine if the HL is conductive, and if so, to restore hearing.
A mathematical model for the determination of mouse excisional wound healing parameters from photographic data
Authors: Cogan Nicholas G. , Mellers Alana P. , Patel Bhavi N. , Powell Brett D. , Aggarwal Manu , Harper Kathleen M. , Blaber Michael
Published: April 2018

We present a mathematical model to quantify parameters of mouse excisional wound healing from photographic data. The equation is a piecewise linear function in log scale that includes key parameters of initial wound radius (R0), an initial wound stasis phase (Ti), and time to wound closure (Tc); subsequently, these terms permit calculation of a latter active proliferative phase (Tp), and the healing rate (HR) during this active phase. A daily photographic record of wound healing (utilizing 6 mm diameter splinted excisional wounds) permits the necessary sampling for robust parameter refinement. When implemented with an automated nonlinear fitting routine, the healing parameters are determined in an operator‐independent (i.e., unbiased) manner. The model was evaluated using photographic data from a splinted excisional surgical procedure involving several different mouse cohorts. Model fitting demonstrates excellent coefficients of determination (R2) in each case. The model, thus, permits quantitation of key parameters of excisional wound healing, from initial wounding through to wound closure, from photographic data.
PlanHab*: hypoxia does not worsen the impairment of skeletal muscle oxidative function induced by bed rest alone
Authors: Salvadego Desy , Keramidas Michail E. , Kölegård Roger , Brocca Lorenza , Lazzer Stefano , Mavelli Irene , Rittweger Jörn , Eiken Ola , Mekjavic Igor B. , Grassi Bruno
Published: April 2018

Key points

Superposition of hypoxia on 21 day bed rest did not worsen the impairment of skeletal muscle oxidative function induced by bed rest alone.

A significant impairment of maximal oxidative performance was identified downstream of cardiovascular O2 delivery, involving both the intramuscular matching between O2 supply and utilization and mitochondrial respiration.

These chronic adaptations appear to be relevant in terms of exposure to spaceflights and reduced gravity habitats (Moon or Mars), as characterized by low gravity and hypoxia, in patients with chronic diseases characterized by hypomobility/immobility and hypoxia, as well as in ageing.

Skeletal muscle oxidative function was evaluated in 11 healthy males (mean ± SD age 27 ± 5 years) prior to (baseline data collection, BDC) and following a 21 day horizontal bed rest (BR), carried out in normoxia ( = 133 mmHg; N‐BR) and hypoxia ( = 90 mmHg; H‐BR). H‐BR was aimed at simulating reduced gravity habitats. The effects of a 21 day hypoxic ambulatory confinement ( = 90 mmHg; H‐AMB) were also assessed. Pulmonary O2 uptake (), vastus lateralis fractional O2 extraction (changes in deoxygenated haemoglobin + myoglobin concentration, Δ[deoxy(Hb + Mb)]; near‐infrared spectroscopy) and femoral artery blood flow (ultrasound Doppler) were evaluated during incremental one‐leg knee‐extension exercise (reduced constraints to cardiovascular O2 delivery) carried out to voluntary exhaustion in a normoxic environment. Mitochondrial respiration was evaluated ex vivo by high‐resolution respirometry in permeabilized vastus lateralis fibres. decreased (P < 0.05) after N‐BR (0.98 ± 0.13 L min−1) and H‐BR (0.96 ± 0.17 L min−1) vs. BDC (1.05 ± 0.14 L min−1). In the presence of a decreased (by ∼6–8%) thigh muscle volume, normalized per unit of muscle mass was not affected by both interventions. Δ[deoxy(Hb + Mb)]peak decreased (P < 0.05) after N‐BR (65 ± 13% of limb ischaemia) and H‐BR (62 ± 12%) vs. BDC (73 ± 13%). H‐AMB did not alter or Δ[deoxy(Hb + Mb)]peak. An overshoot of Δ[deoxy(Hb + Mb)] was evident during the first minute of unloaded exercise after N‐BR and H‐BR. Arterial blood flow to the lower limb during both unloaded and peak knee extension was not affected by any intervention. Maximal ADP‐stimulated mitochondrial respiration decreased (P < 0.05) after all interventions vs. control. In 21 day N‐BR, a significant impairment of oxidative metabolism occurred downstream of cardiovascular O2 delivery, affecting both mitochondrial respiration and presumably the intramuscular matching between O2 supply and utilization. Superposition of H on BR did not worsen the impairment induced by BR alone.
Application of the remote microphone method to active noise control in a mobile phone
Authors: Cheer Jordan , Elliott Stephen J. , Oh Eunmi , Jeong Jonghoon
Published: April 2018

Mobile phones are used in a variety of situations where environmental noise may interfere with the ability of the near-end user to communicate with the far-end user. To overcome this problem, it might be possible to use active noise control technology to reduce the noise experienced by the near-end user. This paper initially demonstrates that when an active noise control system is used in a practical mobile phone configuration to minimise the noise measured by an error microphone mounted on the mobile phone, the attenuation achieved at the user's ear depends strongly on the position of the source generating the acoustic interference. To help overcome this problem, a remote microphone processing strategy is investigated that estimates the pressure at the user's ear from the pressure measured by the microphone on the mobile phone. Through an experimental implementation, it is demonstrated that this arrangement achieves a significant improvement in the attenuation measured at the ear of the user, compared to the standard active control strategy. The robustness of the active control system to changes in both the interfering sound field and the position of the mobile device relative to the ear of the user is also investigated experimentally.
Honeycomb metasurface panel for deep-subwavelength broadband sound absorption
Authors: Peng Xiuyuan , Deng Yuanchen , Jing Yun
Published: April 2018

Honeycomb sandwich panels have long been preferred for their good mechanical properties. Here, we demonstrate a design of honeycomb metasurface panel that can achieve 90% sound absorption from 600 Hz to 1000 Hz with a thickness of less than 30 mm (approximately λ/20) by applying minor modifications to commercialized honeycomb sandwich panels. The panel was made up of periodically and horizontally arranged honeycomb “supercells” which consist of different types of honeycomb unit cells. Each unit cell could be considered a Helmholtz resonator (HR) with hexagonal prism-shaped cavity and cylindrical neck. The absorption performance of designed honeycomb metasurface panel was studied both with surface impedance theory and the complex frequency plane theory, and was then validated by numerical simulations.
Ultrathin Ashoka Chakra like acoustic metastructure as a sound absorber
Authors: Kumar Sanjay , Bhushan Pulak , Bhattacharya Shantanu
Published: April 2018

Absorption of undesirable sound is a fundamental issue with broad applications in a variety of situations, such as in a conference room, cinema hall, aircraft cabin noise, etc. A variety of sound absorbers, e.g., micro-slit, concrete walls, porous media, etc., are used for noise control but are required to have a thickness comparable to the working wavelength. Here, we report a novel ultrathin “Ashoka Chakra” like acoustic metastructure that can be utilized as a sound absorber. The developed acoustic metastructure demonstrates broad bandwidth and high absorption characteristics. Each unit cell contains 24 hollow spokes through which acoustic wavefront can move freely. Despite its simplicity, this approach provides tunability of the metastructure functionality such as operating frequency range by altering the structure dimensions. Finite element based simulations were carried out in order to optimize the metastructure’s dimensions to achieve maximum absorption. The efficacy of the metastructure is validated through excellent agreement between simulation and experimental measurements. Realization of the proposed acoustic metastructure can show promising applications in the field of sound absorption.
Improving traffic noise transmission loss of plenum windows by using sound scatterer arrays
Authors: Tang Shiu-Keung
Published: April 2018

Plenum windows have been used recently in residential buildings erected next to busy trunk roads. These windows are able to provide an additional 8 dB traffic noise reduction than the conventional casement windows, but at the same time they can allow for natural ventilation of the residential units they protect acoustically. The window design consists of two parallel glass panes—one at the building façade (outer) and the other in the indoor side (inner). The outer and inner window openings are located on opposite window of the window span so that they, together with the cavity between the two window panes, form a passage for air movement, while the window’s structure acts as an acoustic filter to attenuate noise. To improve the acoustical performance of this window design, it is proposed in this study to install sound scatterer arrays into the window cavity. It is found from finite-element simulation that such proposal, under appropriate settings, can result in about 4–5 dB improvement of traffic noise transmission loss across a plenum window without significant reduction of air movement across the window. The acoustical performance will further be improved without the increase in air flow resistance when the scatterer rows are staggered.
Ecological momentary assessments for evaluation of hearing-aid preference
Authors: Smeds Karolina , Wolters Florian , Larsson Josefina , Herrlin Petra , Dahlquist Martin
Published: April 2018

Ecological Momentary Assessments (EMA) is a method that involves repeated evaluations in for instance a hearing-device user’s everyday life. Compared to retrospective evaluations, the EMA method minimizes memory bias, and by making several evaluations each day, patterns in the data can be studied. In a pilot study at ORCA Europe, an EMA method was used to evaluate preference for two hearing-aid programs. For two weeks, the test participants were prompted to make evaluations, using a smartphone questionnaire. They were first asked to describe and classify each listening situation into categories such as “conversation with one person” and “monitoring surroundings.” Then they made paired comparisons of the two hearing-aid programs. After the field-trial period, the participants also selected their overall preferred program. Group data for all listening situations pooled showed that the two programs were preferred almost equally often. However, when the data were divided into the seven listening categories, a pattern of preference could be seen. There also seemed to be an association between the test participants’ auditory ecology profiles and their overall preferred program. The study will be presented, and the potential of the EMA method for research, development, clinical evaluations, and individualization of hearing-aid settings will be discussed.
Towards cognitive control of hearing instruments using EEG measures of selective attention
Authors: Dau Torsten , Maercher Roersted Jonatan , Fuglsang Søren , Hjortkjær Jens
Published: April 2018

Single-trial EEG measures of selective auditory attention have recently suggested the perspective of decoding who a listener is focusing on in multi-talker scenarios. Here, we report results from work within the COCOHA (Cognitive Control of a Hearing Aid) project investigating the possibility of integrating EEG into neuro-steered hearing instruments. Our EEG decoding strategy relies on measuring cortical activity entrained to envelope fluctuations in the attended speech signal. Currently, a major challenge has been to obtain robust EEG measures of selective attention in older hearing-impaired (HI) listeners. We report our recent COCOHA attempts to decode selective attention from the EEG of hearing-impaired (HI) listeners. Aided HI listeners and age-matched normal-hearing controls were presented with competing talkers at 0 dB target-to-masker ratio and instructed to attend to one talker. We show that single-trial decoding accuracies similar to those reported for younger listeners can be obtained with both groups of older listeners (70–100% correct single-trial classification). Importantly, we did not find differences in decoding accuracies between the NH and the aided HI listeners. Although numerous other challenges involved in integrating EEG signals in hearing instruments are evident, our results suggest that single-trial attention decoding is possible with hearing impaired listeners.
Robust speech processing in human auditory cortex
Authors: Mesgarani Nima
Published: April 2018

The brain empowers humans with remarkable abilities to navigate their acoustic environment in highly degraded conditions. This seemingly trivial task for normal hearing listeners is extremely challenging for individuals with auditory pathway disorders, and has proven very difficult to model and implement algorithmically in machines. In this talk, I will present the result of an interdisciplinary research effort where invasive and non-invasive neural recordings from human auditory cortex are used to determine the representational and computational properties of robust speech processing in the human brain. These findings show that speech processing in the auditory cortex is dynamic and adaptive. These intrinsic properties allow a listener to filter out irrelevant sound sources, resulting in a reliable and robust means of communication. Furthermore, incorporating the functional properties of neural mechanisms in speech processing models greatly impact the current models of speech perception and at the same time, lead to human-like automatic speech processing technologies.
Speaker-dependent low-level acoustic feature extraction for emotion recognition
Authors: Udhan Tejal , Bernadin Shonda
Published: April 2018

In this paper, accuracy for emotion recognition using low- level acoustic features is investigated. The aim of any speech emotion recognition system is to extract acoustic features that are representative of the emotional state of the speaker. Frequency formants, intensity, and pitch are the low-level features proposed for characterizing four different emotions, anger, happy, sadness, and neutral, using acoustic data. Low- level features describe the acoustic, prosodic, and spectral properties of the speech signal and limit the complexity of emotion recognition systems. An algorithm is designed for characterizing each emotion using the acoustic features. It has been proven that various aspects of a speaker’s physical and emotional state can be identified by speech alone. However, the accuracy of such analyses has not been optimized due to acoustic variabilities such as length and complexity of human speech utterance, gender, speaking styles and speech rate. It has also been found that speaker-dependent systems are more accurate in emotion recognition than that of speaker-independent systems. Since speech emotion recognition is relatively a newer field, the set of most powerful features which can distinguish different emotions is not defined; hence, examining the accuracy of emotion recognition using selected acoustical features is an important task.
Amphibian bioacoustics: From Arch to Zelick
Authors: Narins Peter M.
Published: April 2018

Amphibian bioacoustics may be thought to have originated with the first published acoustic playback experiments with frogs 60 years ago. Martof and Thompson (1958, Behavior 13:243–258) and Littlejohn and Michaud (1959, Tex. Jour. Sci.11:86–92) showed that male calls of Pseudacris nigrita in Georgia are effective in attracting conspecific females, and that females of Pseudacris streckeri in Texas can discriminate conspecific calls from heterospecific calls, respectively. Capranica (1965, JASA 40:1131–1139) was the first to electronically synthesize bullfrog calls and to electronically modify (filter) them for use as stimuli in acoustic playback experiments. Since then, all hell broke loose. Reel-to-reel, cassette and DAT tape recorders, were replaced by wideband portable digital machines capable of recording directly to CF cards and/or to high capacity internal hard drives. Sophisticated call synthesis and analysis programs are widely available. Amphibian communication has been studied on six continents and Madagascar and we have gained a more sophisticated appreciation of the production and reception of amphibian airborne signals. Now the challenge is to find new and interesting amphibian bioacoustic questions, and for inspiration, I shall present a brief review of some of the noteworthy experiments of the past. [Work supported by NSF grant #1555734.]
Effects of azimuthal dependent sediment layer structure on broadband acoustic propagation during Seabed Characterization Experiment in 2017
Authors: Badiey Mohsen , Wan Lin , Goff John A.
Published: April 2018

Seabed physical properties profoundly affect acoustic energy upon interaction. The inherent structural composition of the sediment column interacting with acoustic waves has been a topic of research for decades. Besides the intrinsic physical properties that cause signal attenuation, one of the features that various sediment structures share when interacting with acoustic signals, is causing azimuthal dependence on the broadband acoustic wave propagation. This phenomenon studied in late 1990's [Badiey et al., JASA, 1997a, b] was revisited during the Seabed Characterization Experiment in 2017 (SBCE 2017). The sediment layer structure was obtained from the Chirp Sonar survey collected in the summer of 2015 during pilot study. These data plus CTD and bathymetric measurements are used to construct environmental input along radial tracks for acoustic field computations and range-varying wave number spectral calculations to support SBCE 2017 data analysis. The simulation results show azimuthal variability of acoustic normal modes similar to the experimental data documented in earlier studies [Badiey et al. JASA, 1997 and 2017]. Current results indicate that azimuthal variability of sediment physical properties is one of the causes of acoustic variability in this region. [Work supported by ONR 321OA.]
A study on the sound generation at digital signage using OLED panel
Authors: Park Hyung Woo , Bae Myungjin , Lee SungTae , Park Kwanho
Published: April 2018

With the development of ICT technology and convergence of media and ICT, smart media is spreading to people. The advertising industry through this smart screen is a rapidly growing future industry in the world. A new paradigm of bidirectional/customized features advertisement has become provided through IP-based new media such as smart TVs, portable smart devices, the Internet, IPTV (VOD), and digital signage. As one of the smart advertising industries, the digital signage is attracting attention as the fourth screen after TV, PC, and mobile with indoor/outdoor advertisement using information display. Advertising using the digital signage is installed in a lot of floating population place such as a subway station, a bus stop, an elevator, etc. Digital signage is developed with the display technology and the convergence of IT technology, but the development of appearance and screen configuration is mainly made. There are characteristics of high efficiency when communicate information with visual and auditory. However, up until now, digital signage has been difficult to provide vision and sound to people at the same time. The sound must be played through the screen; nevertheless, the smart screen does not pass the sound well, because of hardware. In this study, we introduce the technology that can generate direct sound using the characteristics of organic light-emitting diode (OLED) panel and introduce digital signage that can transmit video and sound simultaneously by using direct sound generation.
Effects of a straw phonation protocol on acoustic and perceptual measures of choirs
Authors: Manternach Jeremy N.
Published: April 2018

Voice instructors, choral directors, and voice professionals have long utilized semi-occluded vocal tract (SOVT) exercises to evoke efficient voicing from their students or clients. These exercises, which involve narrowing and/or lengthening the vocal tract as a means of increasing pharyngeal pressure, can include nasal consonants, lip or tongue trills, raspberries, or vocalizing through a tube or straw. Researchers have noted that the increased pressure reduces the amount of breath pressure required to initiate voicing (i.e., phonation threshold pressure) while maintaining or increasing acoustic output (e.g., sound pressure level, formant intensity). The result may be increased “vocal economy” or “vocal efficiency” (i.e., increased vocal output with decreased effort). Until recently, however, this research was limited to effects on individuals. This paper includes a series of studies in which choirs of varied voicing (SATB, SSAA, and TTBB) sang unaccompanied pieces prior to and after performing voicing exercises through a small stirring straw. Long-term average spectra have indicated that most choirs maintained or increased acoustic output in the conglomerate, choral sound after the protocols. Singers have also perceived improved choral sound and decreased singing effort. These results may interest choral directors who wish to improve the vocal economy of their ensembles.
The eardrums move when the eyes move: A multisensory effect on the mechanics of hearing
Authors: Gruters Kurtis G. , Murphy David L. , Jenson Cole D. , Smith David W. , Shera Christopher , Groh Jennifer M.
Published: April 2018

Interactions between sensory pathways such as the visual and auditory systems are known to occur in the brain, but where they first occur is uncertain. Here, we show a novel multimodal interaction evident at the eardrum. Ear canal microphone measurements in humans (n = 19 ears in 16 subjects) and monkeys (n = 5 ears in 3 subjects) performing a saccadic eye movement task to visual targets indicated that the eardrum moves in conjunction with the eye movement. The eardrum motion was oscillatory and began as early as 10 ms before saccade onset in humans or with saccade onset in monkeys. These eardrum movements, which we dub Eye Movement Related Eardrum Oscillations (EMREOs), occurred in the absence of a sound stimulus. The EMREOs’ amplitude and phase depended on the direction and horizontal amplitude of the saccade. They lasted throughout the saccade and well into subsequent periods of steady fixation. We discuss the possibility that the mechanisms underlying EMREOs create eye movement-related binaural cues that may aid the brain in evaluating the relationship between visual and auditory stimulus locations as the eyes move.
Applying concepts and tools from signal processing on graphs (SPG) to problems in array signal processing
Authors: Alcantara Eldridge , Atlas Les , Abadi Shima
Published: April 2018

Signal processing on graphs (SPG) is an emerging area of research that extends well-established data analysis concepts and tools to support a special type of signal where data samples are defined on the vertices of a graph. Since SPG emerged in 2013, fundamental operations such as filtering, the Fourier transform, and modulation have been formally defined that uniquely consider and take advantage of the underlying complex and irregular relationship between data elements which is captured mathematically by a graph. The purpose of this study is to analyze the applicability of SPG to array signal processing. We show that signals defined on a graph, or graph signals for short, are natural models for data collected over a line array of sensors. We also apply existing SPG processing algorithms to array signal data and investigate and probe whether SPG can help increase array gain.
Effect of mesoscale eddies on deep-water sound propagation
Authors: Xiao Yao , Li Zhenglin , Sabra Karim G.
Published: April 2018

The mesoscale eddies are the most common mesoscale phenomena in the ocean. The cold and warm water carried by the mesoscale eddies can significantly change the structure of the sound speed field, which is the key factor affecting long range deep-water sound propagation. In this presentation, a deep-sea analytical eddy model [Henrick et al., JASA 62, 860–870(1977) ] is used to determine the sound speed distributions produced by cold eddy in the southwest of the South China Sea. The statistical characteristics of the influence of eddies on the acoustic propagation are investigated with a range-dependent parabolic equation (PE) model to asses the effects of the relative position of sound sources and eddies, the frequency sensitivity, the acoustic energy deviation of the convergence zone and the shadow zone for long-range (600 km) low frequency (50 Hz) sound propagation in this ocean model. Specific features of the induced sound propagation variability such as the travel time deviation and the standard deviation of ensemble intensity Will be quantified. Finally, the refraction due to mesoscale eddies on large scale low-frequency propagation is discussed using the full three-dimensional parabolic (FOR3D) and explaining by the full three-dimensional ray theory (Bellhop3D).
The use of background noise to mask objectionable sounds to rodents
Authors: Bruce Robert D. , Bommer Arno S. , Harwell Isaac , Young Adam , Meynig Max
Published: April 2018

Construction noise and vibration can interrupt sleep/concentration of humans during renovations. Noise treatments or vibration breaks can reduce the impact. But could background noise cover up a moderate level of construction noise? Innocuous sounds are used to mask quieter but more annoying sounds. The concept is commonly used in offices to aid in concentration and reduce annoyance in places where people work or sleep. But could it be used to mask construction noise if the recipients were rodents rather than people? In theory, the concept of sound masking should be valid for other species of animals. Excessive noise and vibration has been shown to affect rodent behavior including breeding. Their hearing, extending into the ultrasound region, complicates efforts to recognize and measure the rodents’ acoustical environment. During the past several years, we have had occasion to study the literature on rodents’ hearing and the use of masking to prevent the creatures from being bothered by intruding sound. In this paper, we summarize the literature and investigate the concept of masking for rodents with respect to regularly encountered sound sources and sounds from construction activities.
Copulation calls of female chimpanzees (Pan troglodytes) signal fertility
Authors: Massaro Anthony P. , Boehm Emily E. , Lonsdorf Elizabeth V. , Murray Carson M. , Stanton Margaret A. , Wilson Michael
Published: April 2018

In many species, females produce vocalizations during or soon after mating. In chimpanzees, these calls accompany only some matings while visual signals of sexual receptivity are always visible. Proposed explanations for chimpanzee copulation calls include (1) increasing paternity confusion and thus reducing infanticide risk, and (2) competing more effectively with other females for male mating interest. We used information theoretic model selection to test competing hypotheses using a record of 1,168 copulation events recorded by the mother-infant project team at Gombe National Park, Tanzania (1976-2015). We found that females produced copulation calls more frequently in the last week of their reproductive cycle, when they are most fertile. This timing is consistent with the hypothesis that copulation calls function as an honest signal of fertility. While females also signal fertility visually (with sexual swellings), copulation calls may signal to a broader audience, encouraging males to invest in mating effort. Male primates are often portrayed as always being ready to mate, but in reality, mating entails potential costs for males, including the risk of aggression from other males, and opportunity costs that must be weighed against the risk of mating with a non-ovulating female.
Analysis of Haddock (Melanogrammus aeglefinus) sounds recorded in the Northwest Atlantic
Authors: Mouy Xavier , Rountree Rodney A. , Burchard Katie A. , Juanes Francis , Dosso Stan E.
Published: April 2018

Haddock (Melanogrammus aeglefinus) are present on both sides of the North Atlantic. Their distribution in the Northwest Atlantic ranges from Greenland to North Carolina. They are an important food resource that needs to be closely monitored to ensure a sustainable fishery. Research studies have reported that both male and female haddock produce sounds during courtship and spawning. These sounds can be used to monitor spawning activities non-intrusively and at large scale. The objective of this paper is to analyse the spatial and temporal occurrence of Haddock sounds in the Gulf of Maine. Passive acoustic data were collected in 2003, 2004, 2006, and 2007 in areas known to contain spawning haddock. To analyze the large amount of data collected, an automated haddock sound detector was developed based on a measure of kurtosis and the Dynamic Time Warping algorithm. The detector was trained using the 2006 and 2007 data and its performance was quantified and optimized by comparing detection results with manually annotated Haddock sounds. The detector was then used to analyze data collected in 2003 and 2004. Results provide information on the temporal and spatial distributions of courtship and spawning sounds.
Temporal information processing in gray treefrogs: Compute within frequency then integrate across frequency
Authors: Gupta Saumya , Bee Mark
Published: April 2018

In Cope’s gray treefrog (Hyla chrysoscelis), the pulse rate of advertisement calls is a species recognition cue. This temporal information is redundant across two spectral bands in the call’s bimodal spectrum that are primarily transduced by different inner ear papillae. Previous studies have shown that some neurons in the frog auditory midbrain are selective for bimodal spectra and that, compared with unimodal spectra, calls with bimodal spectra are more attractive. In addition, “interval-counting” neurons in the frog auditory midbrain are selective for conspecific pulse rates. However, it is not known whether pulse rate information is computed prior to, or subsequent to, spectral integration. We conducted behavioral experiments to investigate the serial order of pulse rate computations and spectral integration. In phonotaxis tests that used bimodal and unimodal stimuli with variable pulse rates, we tested the hypothesis that spectral information is integrated prior to pulse rate computations versus the alternative hypothesis that pulse rate can be computed independently in different frequency channels prior to spectral integration. Our results support the latter hypothesis, and suggest pulse rate can be computed independently in separate frequency channels. These results give insight into the mechanisms of temporal processing underlying the perception of key biological information.
Within-individual variation in signal production limits female choice in noisy treefrog choruses
Authors: Tanner Jessie C. , Bee Mark
Published: April 2018

In acoustically communicating animals such as anurans and orthopterans, individual signalers can display remarkable variation in signal traits, even within a single bout of calling. This within-individual variation has the potential to “mask” the between-individual variation that is the target of sexual selection. Thus, receivers may not always be able to discriminate among males based on properties of their acoustic signals, even when female choice is well documented in the lab. The effect of within-individual variation may be compounded by noise generated by breeding choruses of conspecifics, which can prevent signal detection or discrimination. We manipulated within-individual variation in two signal traits (call rate and pulse rate) that are critically important for mate choice in Hyla chrysoscelis, Cope’s gray treefrog. We replicated our design at three realistic levels of chorus noise. Within-individual variation in signal traits reduced the strength of sexual selection on one of two traits, and receivers were less likely to discriminate against lower-quality signals under conditions of realistic chorus noise. Our results suggest that preference functions generated using stimuli that lack within-individual variation, under ideal listening conditions, may chronically over-estimate the strength of sexual selection on signal traits in natural populations.
New sampling and filtering approaches to label-free ultrasonic perfusion imaging
Authors: Zhu Yang , Kim Minwoo , Insana Michael F.
Published: April 2018

Color-flow and power Doppler imaging are safe, low-cost, non-invasive techniques for assessing blood flow throughout the body. Imaging microvascular flows and perfusion generally requires injectable contrast agents to separate tissue clutter from blood echoes. Our innovation is to modify echo acquisition to expand data dimensionality and increase sensitivity of non-enhanced PD imaging to very slow, disorganized flows. To separate perfusion from other echo signals, we developed a higher-order singular value decomposition filter that appropriately reduces data dimensionality. Effective elimination of clutter and noise results improved perfusion specificity. Our methods are applied to existing commercial US instruments, which makes them immediately valuable to medical practice. Our methods were previously tested at 24 MHz in a study involving muscle ischemia and highly-vascular melanoma lesions in mice. This study translates the methods to lower frequencies (5-10 MHz) for human trials. We developed a dialysis-cartridge device using TM-blood to quantifying very slow flow in the presence of tissue-like clutter and noise. We calibrated our technique to quantify the sensitivity, dynamic range, and spatial resolution of PD imaging. Results indicate an ability to separate flow speeds as low as 0.3 mm/s from clutter signals.
Phantom study of flow speed measurement using ultrafast ultrasound plane wave imaging
Authors: Zhou Boran , Zhang Xiaoming
Published: April 2018

Color flow imaging is an ultrasound imaging technique widely used to image the blood movement through arteries and veins. Quantification of velocity is urgently demanding. The objective of this study is to use ultrafast plane wave imaging to measure the flow in speed in vitro. For the flow phantom, the diagonal vessel (2-mm inner diameter at 40° angle) was studied with injection of blood mimic fluid via syringe pump at various volume rates (15, 20, 25, and 30 ml/min). Verasonics Vantage system (Verasonics Inc., Kirkland, WA, USA) and a linear array transducer L11-4v (Verasonics Inc., Kirkland, WA, USA) were used for ultrasound acquisition, a 8-angle (−7° to 7°) plane wave compounding with effective pulse-repetition frequency (PRF) of 1000 Hz was used (central frequency = 6.42 MHz, number of transmit cycles = 4). A total of 600 ensembles were acquired. The frame rate was 1000/s.[XZ1] [BZ2] The ultrasound in-phase quadrature data size was 195 × 156 × 600 (axial x lateral x temporal) with data type of complex double. Singular value decomposition (SVD)-based ultrasound blood flow clutter filters was used for ultrafast plane wave imaging.[XZ3] [BZ4] Randomized SVD was utilized to filter noise and tissue motion. Power Doppler image was generated. The color flow images were generated by using the 2-D autocorrelation method. Results showed that color flow measurement can quantitatively evaluate the flow speed in the tube of the flow phantom.
Compound speckle model demonstrates two-phase wash-in of contrast-enhanced ultrasound cine loops
Authors: Lowerison Matthew R. , Chambers Ann F. , Leong Hon S. , Power Nicholas E. , Lacefield James C.
Published: April 2018

During contrast-enhanced ultrasound (CEUS) imaging of tumor microvascular perfusion, nearby arteriole enhancement can be a dominant feature of the wash-in kinetics that obscures the perfusion characteristics of the capillary bed. This presentation demonstrates that statistical wash-in curves generated using our compound CEUS speckle model1 exhibit two distinct phases corresponding to “fast-flow” and “slow-flow” enhancement that can be detected by fitting a linear combination of two monoexponential functions with different time constants. CEUS cine loops were acquired from a patient-derived xenograft model of renal cell carcinoma, where fresh tumor fragments were engrafted into the chicken embryo chorioallantoic membrane. Subharmonic CEUS images were acquired at 18 MHz using a destruction-replenishment protocol. Enhancement of manually segmented tumor cross-sections was analyzed offline in MATLAB. The CEUS cine loops from this xenograft model frequently exhibited in-plane arteriole enhancement. The two-phase fit discriminated a slow-flow component in 26.6% of time-intensity wash-in curves and 62.9% of the statistical wash-in curves, leading to a decrease in estimated tumor blood volume by 22.1% and 24.7%, respectively, compared to a simple monoexponential fit. These results suggest that conventional CEUS processing may frequently overestimate capillary blood volume. 1M.R. Lowerison et al., Med. Phys. 44, 99-111 (2017).
Transduction technologies for structural acoustics sonars
Authors: Tressler James
Published: April 2018

This presentation will describe underwater acoustic transduction technologies that the Naval Research Laboratory (NRL) has developed for structural acoustics sonars. The NRL “Skyfish” downward-looking sonar system is deployed on a 21-inch diameter autonomous underwater vehicle (AUV) that features a pair of extendable/retractable wings, each of which houses a thirty-two element cylindrical hydrophone array. The well-behaved acoustic source consists of a pair of transducers, each covering a separate frequency band. The source is designed to provide a fairly wide acoustic aperture for looking both fore and aft as well as in the port and starboard directions. Architectural details of the source and receiver, materials considerations, amplifier design, and experimental data will be presented. [This work supported by the Office of Naval Research & ESTCP.]
Design issues for eigenbeamforming spherical microphone arrays
Authors: Elko Gary W. , Meyer Jens
Published: April 2018

Approximating an analytic function by orthonormal bases functions has its origins in the theory of least squares developed by Gauss and Legendre. The use of orthonormal bases functions has been a standard tool in soundfield analysis since Rayleigh. One common set of orthonormal bases functions that naturally fit the solution of the spherical wave equation are the spherical harmonics. In this talk we describe the concept of building a microphone array on a rigid spherical baffle. We process the output signals from the spherical array such that we spatially decompose the acoustic soundfield into spherical harmonic Eigenbeam signals. Computationally efficient Eigenbeamforming, or modal beamforming, with these processed Eigenbeam signals will be discussed. Two main design issues are the growth in sensitivity to self-noise for higher-order spherical modes at lower values of k*r where, k is the wavenumber and r is the radius, and spatial aliasing due to the finite number of microphones covering the spherical surface at higher values of kr. We will discuss how to practically handle these design issues and how these design solutions impact the overall performance of the Eigenbeams and the use of these components in the design of modal beamformers.
Optical breakdown as a broadband underwater acoustic source
Authors: Athanassiadis Athanasios G.
Published: April 2018

Current underwater transducers provide little support for remote measurement of material properties. Such measurements are often limited by high impedance contrast, and target inhomogeneities that arise from biofouling and corrosion. In the presence of these limitations, a sensing system would benefit from broadband, spatially-localized target excitation. The high bandwidth would allow a return signal to encode broader information content about the target, while spatial localization would provide stronger target excitation and higher spatial resolution for measurements. Although these source properties are not achievable with traditional transducer designs, they can be produced through laser-induced optical breakdown in water. During optical breakdown, focused laser light excites a localized plasma, which expands and produces a mechanical shock wave. The shock properties are set by both the medium hydrodynamics and the laser parameters, allowing the acoustic source to be optically tuned. In laboratory experiments, breakdown from a 4 mJ/ 4ns laser pulse emits an exponential pressure wave with a decay constant under 250 ns and peak pressure near 600 kPa at 2 cm range. Here, I discuss the physics and fundamental limitations of acoustic transduction via underwater optical breakdown. Experimental results illustrate how the acoustic source properties can be tuned through optical control.
Comparing the similarity of sharpness predictions based on specific loudness from ANSI S3.4-2007 with those according to DIN 45692:2009 for several real-world sound classes
Authors: Swift S. Hales , Gee Kent L.
Published: April 2018

A previous paper [Swift and Gee, Proc. Mtgs. Acoust., p. 030001, 2017] showed methods for transforming the standardized form of sharpness to accept inputs from the ANSI S3.4-2007 loudness standard. A further recent publication [Swift and Gee, JASA-EL, 2017] showed additional validation results comparing the results of the simplest version of the transformed metric for a set of 40 real-world sounds. In this paper, three versions of the ANSI-based sharpness metric are analyzed, in order to determine which of the three implementations gives the most similar results to the original DIN 45692:2009 standard. Finally, classes of sounds are identified for which predictions between the three ANSI-based sharpness metrics and DIN 45692:2009 may differ to a greater or lesser extent.
Types of regulatory tools and their advantages, limitations, and disadvantages in a Model Noise Ordinance Standard
Authors: Blomberg Leslie D.
Published: April 2018

The American National Standards Institute is developing a model community noise ordinance. There are seven types of regulatory tools available to communities to regulate noise that can be used in a model noise ordinance. These include (1) nuisance based regulations, (2) disturbing the peace regulations, (3) decibel based regulations, (4) plainly audible regulations, (5) operational restrictions and prohibitions, (6) equipment requirements, and (7) quiet zones. In this paper, each is described, as well as the advantages, limitations, and disadvantages of each tool. A Matrix of Advantages of Regulatory Tools Used in Community Noise Regulation is presented and provides easy comparison between the regulatory tools. This matrix can provide the basis for a proposed Model Noise Ordinance standard.
Examining the effect of emerging audio formats and technology on acoustical space in film composition and mixing
Authors: Cook Conor P.
Published: April 2018

Because film audio must balance the three basic soundtrack elements of dialogue, music, and effects, acoustical masking and professional disagreements during the post-production mixing process affect the importance given to the film score. Dialogue is customarily and logically given priority, causing film composers and music mixers to work around the acoustical space taken up by speech, typically through panning, equalization, avoidance of speech frequencies, and “density” in orchestration. Improvements in audio systems and formats, such as surround sound and now Dolby Atmos, are affording composers and mixers more acoustical space to avoid masking effects without a loss of dramatic support for the film, including the introduction of height cues and greater surround panning control, as well as sound objects, which control the localization of discrete sounds in 3D space. The new technologies also present acoustical design challenges as they interact in surprising ways with specific “acoustic signatures” of widely-varying media presentation spaces. Acoustical environment examples from earlier and recent film mixes as well as critical literature are given. Composers and mixers are encouraged to explore the range of expressive acoustical options made available by emerging technologies and the more widely-compatible mixing spaces designed for them.