bluuebunny/crossref_metadata_2025 huggingface dataset:
China green campus school standard
Authors: Roy Kenneth P. , Li Xiao
Published: April 2018

Since 2011 I’ve been involved as a principal investigator (Armstrong World Industries) on several research programs encompassing approximately 100 primary and middle grade schools throughout China. Initially, this research was coordinated with Tongji University for the development of the Chinese Green Campus rating system for schools, and later, we have worked with the Beijing Ministry of Education and several additional Universities including Tsinghua Univ., South China Univ. of Technology, Chongqing Univ., and Huaqiao University for the development of the new China GB Green Campus Standard. The “learnings” from these research studies will be reviewed, and the outcomes in terms of implementation will be discussed. A “playbook” was developed for the government architects who design schools, as a simple process for meeting the design goals, and understanding the installed costs for specific use areas. School acoustics is an important IEQ factor in the design and performance of the school in meeting its mission—which is for teachers to teach and students to learn.
New research on low-frequency membrane absorbers
Authors: Calder John
Published: April 2018

Low-frequency (LF) room modes are one of the greatest issues for accurate sound recording and reproduction. Effective LF absorbers can mitigate modes in professional and consumer audio rooms. However, fiber- and foam-based absorbers act on sound velocity; membrane absorbers act on sound pressure (greatest at hard surfaces and corners). Velocity at hard surfaces is zero; thus, fiber and foam absorbers work far less effectively than membrane absorbers under 200Hz. Additionally, most independent testing laboratories are only large enough to accurately measure absorption results above 160Hz (per Schroeder frequency) but not below. Only one lab is large enough to be accurate down to 40Hz. A new LF membrane-based absorber product was designed to compliment the frequency range of an existing product. Both were separately tested for LF absorption down to 40Hz at the above-referenced lab. Ten LF absorber tests revealed that the type of absorber, and its location and orientation in a room, are critical to LF absorber effectiveness. Some unexpected results, however, showed clearly that without standardized laboratory absorption testing in a lab capable of accurately testing down to 40Hz, it is not possible to state conclusively that low-frequency absorber products perform as claimed.
Calls of the bald eagle (Haliaeetus leucocephalus)
Authors: Walsh Edward J. , Nelson Peggy , Byrne Andrew , Marr Jeff , Feist Christopher , Milliren Christopher , Ponder Julia , Redig Patrick , McGee JoAnn
Published: April 2018

Injury and mortality statistics suggest that bald eagles entering the air space of wind energy facilities face considerable risk. To mitigate the hazard, acoustic deterrent systems designed to discourage entry into such hazardous air spaces are under consideration. In this study, the acoustic properties of a collection of call types within the eagle vocal repertoire are reported as a first step in a larger program of study designed to assess the deterrent capacity of the bird’s natural vocal utterances. To that end, calls were recorded from bald eagles housed in the Raptor Center at the University of Minnesota. Based on preliminary acoustic analyses, at least five calls were identified and are referred to here as peal/scream, chatter/cackle, snort, squeal and grunt. With the exception of the low frequency grunt, calls were uniformly high pitched, tonal in nature, exhibited harmonic spectral structure, and they were generally complex, exhibiting distinct nonlinear characteristics. In this presentation, the spectrotemporal properties of each call type will be described with the goal of generating an acoustic repository to enable the consistent classification of calls to be tested for their potential as deterrence signals. [This work was supported by Department of Energy grant #DE-EE0007881.]
The effects of noise and age on the detection of ultrasonic vocalizations and pure tones by laboratory mice
Authors: Kobrina Anastasiya , Dent Micheal L.
Published: April 2018

Mice are frequently used to study and model age-related hearing loss (ARHL) due to similarities in human and mouse cochleae and in genetic makeup. Mice emit ultrasonic vocalizations (USVs) that may be used for communication. Behavioral research has established that mice exhibit ARHL for detection of USVs and pure tones, however later in life than previously estimated by electrophysiological methods. In addition, mice showed sex-related ARHL differences for USVs but not for 42 kHz tones. In order to fully understand whether mice can be used to model ARHL it is critical to examine hearing loss for simple and complex stimuli in a variety of listening environments. In this study, detection thresholds were measured in adult mice using operant conditioning procedures and positive reinforcement. Mice were trained to detect USVs and high frequency pure tones in silence and in 50 dB white noise. The results revealed that adult mice retain hearing late into their lifespan, with very old mice exhibiting higher thresholds for USVs and pure tones in noise than in silence. The results highlight the importance of measuring hearing in awake, trained, behaving subjects when comparing ARHL across different species. [This work was supported by F31 DC016545 and R01 DC012302.]
A frog’s lungs sharpen the frequency tuning of its peripheral auditory system: A pulmonary paradox resolved?
Authors: Bee Mark , Lee Norman , Christensen-Dalsgaard Jakob
Published: April 2018

In frogs, sound localization is facilitated by the directionality of their internally coupled ears, which are connected through the mouth cavity and Eustachian tubes. Acoustic input through the frog’s body wall and lungs also shapes the ear’s directionality. One hypothesized function of the lung input is to enhance directional hearing to improve localization of conspecific calls. However, an unresolved paradox exists: the lung input often improves directionality at frequencies that are intermediate between those emphasized in conspecific vocalizations. The present study of green treefrogs (Hyla cinerea) may resolve this paradox. Using laser vibrometry, we show that the lung input improves directionality at frequencies emphasized in conspecific calls by just 2 dB or less. In contrast, the lung input reduces the frontal field sensitivity of the tympanum by up to 7 dB in response to frequencies that are intermediate between those emphasized in conspecific calls and to which the two inner ear papillae are tuned. These results suggest the lung input may function in communication by sharpening the frequency tuning of the peripheral auditory system, which in turn could filter out frequencies in heterospecific calls in some mixed-species choruses. How the lung input achieves this “noise cancellation” is currently under investigation.
Ultrasonic non-contrast perfusion imaging with adaptive demodulation
Authors: Tierney Jaime , Byram Brett
Published: April 2018

Ultrasonic non-contrast perfusion imaging remains challenging due to spectral broadening of the tissue clutter signal caused by patient and sonographer hand motion. Simply, the velocity of the slowest moving blood has similar spectral support to the moving tissue. To address this problem, we developed an adaptive demodulation (AD) scheme to suppress the bandwidth of tissue prior to high-pass filtering. The method works by directly estimating the modulation imposed by tissue motion, and then removing that motion from the signal. Our initial implementation used single plane wave power Doppler imaging sequence combined with a conventional high-pass IIR tissue filter. However, other recent advancements in beamforming and tissue filtering have been proposed for improved slow-flow imaging, including coherent flow power Doppler (CFPD) and singular value decomposition (SVD). Here, we aim to evaluate AD separately as well as in comparison and in conjunction with improvements in beamforming and filtering using simulations and an in vivo muscle contraction experiment. We show that simulated blood-to-background SNR is highest when using AD + CFPD and a 100 ms ensemble, which resulted in a 9.88 dB increase in SNR compared to CFPD by itself. Additionally, AD + SVD resulted in a 54.6% increase in mean power within the in vivo muscle after contraction compared to a 6.84% increase with AD and a conventional IIR filter.
Quantitative morphological analysis of microvasculature in thyroid nodules using non-contrast high-resolution Doppler imaging
Authors: Ghavami Siavash , Bayat Mahdi , Gregory Adriana , Kim Bae Hyeong , Viksit Kumar , Webb Jeremy , Fatemi Mostafa , Alizad Azra
Published: April 2018

We hypothesize that pattern of microvasculature in the thyroid nodules can be a biomarker of thyroid cancer. In this study, morphological features of microvasculature networks are assessed as potential biomarkers for differentiation of benign, suspicious and malignant thyroid nodules. This prospective study included n = 81 patients, with a total of 61 benign, 12 suspicious and 8 malignant nodules verfied by pathology and cytology findings. Thyroid nodules were first identified using conventional B-mode ultrasound. A sequence of raw ultrasound data were acquired from each nodule site in two perpendicular planes at ~600 frames/sec. Power Doppler image of the microvasculature was formed using singular value decomposition clutter removal filtering. Gross images were further processed using a combination of morphology and Hessian-based vessel enhancement filtering. Background-free images of the microvasculature networks were segmented (vessels segment length >385μm and diameter >90μm) for morphological analysis. Using a Bayesian framework, measures of vessels density, diameter and tortuosity were tested for significant differences in the three groups. Among all measures, the probability of vessel diameter >600μm in benign cases was significantly higher than that in malignant cases with the p-value <0.01 using Wilcoxon-Rank-Sum test, suggesting reliable cancer detection performance of the proposed method. [Acknowledgment: NIH Grant EB17213.]
Acoustical standards in the national parks
Authors: Fristrup Kurt M.
Published: April 2018

U. S. National Parks began actively conserving park acoustic resources decades after U. S. community noise management practices were established. This presented opportunities to benefit from the knowledge acquired in community noise settings and challenges to adapt this knowledge and devise new methods as appropriate for national park settings. Participation in ANSI/ASA accredited standards development processes provided numerous benefits to the National Park Service (NPS): Access to a substantial fraction of the world’s experts in acoustics, noise measurement, and noise reduction, many of whom were deeply involved in the development of community noise standards, Participation in an open, formal, coordinated, consensus-based process to develop voluntary standards, Engagement of a diverse range of stakeholders to develop standards through processes of cooperation and compromise, Conformance with the Office of Management and Budget’s requirement to use voluntary consensus standards in lieu of government-unique standards (Circular A-119). NPS is an institutional member of two accredited standards committees and participates in the leadership of one committee and one working group. One standard has been published from this working group (ANSI S3-SC1.100 and ANSI S12.100: Methods to Define and Measure the Residual Sound in Protected Natural and Quiet Residential Areas). A second standard is in development.
Improving practices through analysis of long-term microphone calibration records
Authors: Ochi Gordon M. , Blevins Matthew G. , Lyons Gregory W. , Nykaza Edward T.
Published: April 2018

A microphone’s history of calibration is a useful source of information, as an independent analysis of the data can reveal more than simply the metrological traceability. The U.S. Army Engineer Research and Development Center maintains over 13 years of calibration records from an inventory of over 280 Class 1 microphones, which were examined for historical validity and consistency. Analyzing trends in the laboratory reported sensitivities showed that 12.9% of active microphones exhibited four possible trends that could indicate potential microphone failure: sensitivity drift, sensitivity drift followed by instability, jump in sensitivity, and general instability. Many of the microphones that displayed these trends had uncertainties greater than a ± 1.0 dB tolerance inferred from ANSI S1.14 Class 1 microphone specifications, and an additional 10.7% of microphones showed errors in the calibration laboratory’s transcription process or testing procedures. Recommendations are put forth for best practices relative to laboratory independent microphone calibration record documentation and analysis, and a quantitative procedure for flagging microphones was developed. Specifically, it is recommended that microphones with a component type ‘A’ uncertainty due to the history of calibrations that exceeds ± 1.0 dB be removed for further inspection, in reference to the Class 1 microphone specifications in ANSI S1.14.
History of the sound level meter in standards
Authors: Blomberg Leslie D.
Published: April 2018

In 1932, the Acoustical Society of America started work on the first American Standards Association standard for sound level meters. The purpose was to create a set of standards for sound level meters “such that, if a given noise of a general character is measured with any meter designed in accordance with the standards, the result will be substantially the same as that which would be obtained with any other similarly designed meter.” The standard that resulted, Z 24.3 1936 was the first of many that trace the development of the sound level meter over the past 86 years. This paper follows the history and development of the sound level meter in the original American Standards Association and subsequent American National Standards Institute standards: Z 24.3 1944, S1.4 1961, S1.4 1971, 1.4 1983, and S1.4 2014. During that time the sound level meter has shrunk from a more than 100 pound, vacuum tube machine to a modern the modern, lightweight meter. The standard, however, has grown from a mere 11 pages in 1936 to 50 pages in 2014.
Articulatory correlates of the acoustic transition during the second passaggio of sopranos
Authors: Lissemore Richard C. , Roon Kevin , Shadle Christine H. , Whalen D. H.
Published: April 2018

The present experiment examines articulatory correlates associated with the presence or absence of a change in A1-A2, the amplitude difference between the first two harmonics (fo and 2fo),in the second passaggio transition (D5♮ to F5♮, or 587 to 698 Hz) of the soprano voice. An earlier investigation of this area in a classical, techniqued soprano singing on a low vowel revealed a change from negative to positive values in A1-A2 at a pivot point between E5♭ and E5♮. But when the same singer produced sounds without technique, the A1-A2 values remained negative. The present articulatory investigation uses ultrasound and optical tracking for analysis of head-corrected tongue contours, jaw opening, lip aperture, and lip protrusion that accompany the presence or absence of the acoustic change in this same singer. Preliminary results replicate the relationship between the acoustic change from negative to positive values of A1-A2 and show a substantial change in tongue dorsum height. In contrast, singing that exhibits only negative values of A1-A2 shows no such articulatory changes. The same experimental protocol was then used with sopranos who can and cannot make the A1-A2 acoustic change. Acoustic and articulatory results will be reported. [Funded by NIH grant DC-002717.]
Correlation of string/body resonances on a cello
Authors: Young Samantha A.
Published: April 2018

This project focuses on a 2001 Garavaglia full size acoustic cello, and investigates the resonance properties of a wooden body. Previous studies have estimated that the body resonance lies between the range of D3-F3#. The goals are to investigate the radiation patterns of the produced sound waves, to take high-speed video of a played string to physically observe the standing wave, and to simulate the body resonance of the cello. A mathematical model is formed to approach the situation where a musician plucks a string. Typical approaches assume the surface area of a finger to be a point source, but the surface area is actually parabolic, forming a bend in the string that is continuous to the following straight line. High speed video was taken to try out methods for tracking a standing wave at 1000 frames per second for a maximum number of data points per period. We will correlate the waveform fits from the high speed videos to the Fourier transformations from the acoustic data. These same methods will be applied in an anechoic chamber to test “ideal” conditions in order to isolate the body resonances. We will correlate the data from body resonances to our string data.
Atmospheric turbulence effects on sonic boom signatures
Authors: Hobbs Christopher , Bradley Kevin
Published: April 2018

Two measurement campaigns were conducted as part of a study to quantify the effect of atmospheric turbulence on sonic boom propagation. Supersonic overflights were conducted at the NASA Armstrong Flight Research Center and the Kennedy Space Center to provide different atmospheric conditions for study. Measurements were made of the strength of the turbulence along with the height of the atmospheric boundary layer. Multiple microphone arrays recorded the sonic booms from instrumented aircraft. This work will present statistics detailing the variation of measured booms as a function of the strength of the turbulence and the propagation distance through the atmospheric boundary layer. [Work supported by NASA.]
Mean flow atmospheric effects and their impact on sonic boom propagation
Authors: Rallabhandi Sriram
Published: April 2018

One dimensional augmented Burgers equation has been generally used for nonlinear lossy sonic boom propagation. This equation models the effects of nonlinearities, loss mechanisms such as absorption and dispersion due to molecular relaxation and thermoviscous dissipation, and geometric spreading through ray tube areas including Blokhintzev scaling as well as atmospheric stratification. However, in the presence of atmospheric winds, original terms in the augmented Burgers formulation do not account for the Doppler effects, where the observer is moving with the local flow rather than being fixed in space. Instead, wind is accounted for by updating the ray paths and effective speed of sound. Inclusion of mean flow wind effects in all terms of the augmented Burgers equation allows for an enhanced prediction capability that is closer to the underlying physics. This work will update sBOOM, an augmented Burgers' solver, to reflect the mean flow wind enhancements. The sonic boom ground signatures and other relevant data are compared against those obtained without using mean flow wind effects. The shock rise times, sonic boom duration and peak pressures are some variables that are expected to be different, resulting in differences in noise metrics. Such differences will be discussed and documented for cases which may include shaped low-boom as well as strong shock signatures.
The contribution of Neal Veimeister to the modulation theory of hearing
Authors: Lorenzi Christian
Published: April 2018

Neal Viemeister has dedicated his scientific career to one of the most influential research programs in hearing sciences. This program aims to apply the modulation theory to auditory perception. This theory, inspired by telecommunication sciences, relies on the following assumptions: (i) communication sounds including speech and animal vocalizations convey salient and slow temporal modulation cues; (ii) the auditory system of species using communication sounds has evolved to optimize its responses to these modulation cues; (iii) the transmission of information conveyed by communication signals is constrained by the ‘modulation transfer function’ (MTF) of the transmission path (a room, a hearing aid,...). We will show how the pioneering work of Neal Viemeister on the ‘temporal MTF’ and his rigorous investigation of modulation perception by human listeners contributed to an in-depth understanding of the demodulation processes implemented in the peripheral and central auditory system. We will show how his work yielded to models of modulation processing that account for a large range of listening situations including speech intelligibility and texture perception. Finally, we will show how his work contributed to a better understanding of the perceptual consequences of ageing and cochlear damage, and a better control of information transmission via rehabilitation systems.
Design, optimization, and fabrication of mechanical metamaterials for vibration control
Authors: Walsh Timothy F. , Hammetter Chris , Sinclair Michael B. , Shaklee-Brown Harlan , Bishop Joe , Aquino Wilkins
Published: April 2018

Harsh shock and vibration environments are common in engineering applications. Mechanical metamaterials are showing significant potential as candidates for controlling wave propagation and isolating sensitive structural components, but require proper design of their complex microstructures. In this talk we will present time and frequency-domain strategies for Partial Differential Constrained (PDE)-constrained design optimization of locally resonant elastic/acoustic metamaterials. We will present a variety of notch filter resonators and split ring cylinder/sphere geometries that can be easily optimized for wave control applications, along with fabrication details involving multi-material additive manufacturing. A frequency-domain approach will be presented for band-gap or notch filter materials, and a time-domain strategy for transient shock environments. As the metamaterial structures typically involve concentrated masses and elastic connections, an optimization strategy involving 3D simple shapes will be presented. [Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, C.A., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.]
Extraordinary wave phenomena in active acoustic metamaterials
Authors: Fleury Romain
Published: April 2018

Non-Hermitian sonic metamaterials are artifical acoustic media that exploit gain and loss as an extra degree of freedom to induce novel physical effects that cannot be obtained with lossless or trivial lossy systems. In this talk, we will review our recent theoretical and experimental results about one-dimensional non-Hermitian acoustics, highlighting the ability of active metamaterials to overcome limitations of passive metamaterials by engineering the acoustic power flow at the microscopic scale. We will discuss various experiments employing a set of electroacoustic resonators in a pipe, engineered to provide tailored distributions of acoustic gain or loss, and discuss the potentials of such systems in terms of sound manipulation. Altogether, our work points out the large potential and rich physics of non-Hermitian acoustic metamaterials.
Underwater acoustic ground cloak development and demonstration
Authors: Kerrian Peter , Hanford Amanda , Beck Benjamin , Capone Dean
Published: April 2018

Acoustic ground cloaks, which conceal an object on a rigid surface, utilize a linear coordinate transformation to map the flat surface to a triangular void by compressing space into two triangular cloaking regions consisting of a homogeneous anisotropic acoustic metamaterial. Transformation acoustics allows for the realization of a coordinate transformation through a reinterpretation of the scale factors as a new material in the original coordinate system. An underwater acoustic ground cloak was constructed from perforated steel plates and experimentally tested to conceal an object on a pressure release surface. The perforated plate acoustic ground cloak successfully cloaked the scattered object. There was excellent agreement between the phase of the surface reflection and cloak reflection with a small amplitude difference. Above 15 [kHz], the cloaking performance decreased as the effective material parameters of the perforated plate metamaterial deviated from the required material parameters.
On the behavior of acoustic/elastic metamaterials with anisotropic mass density
Authors: jaberzadeh mehran , Li Bing , Tan Kwek Tze
Published: April 2018

The effect of anisotropic mass density in acoustic/elastic metamaterials on wave propagation is presented in this research. The use of microstructures to achieve anisotropic physical properties in metamaterials is an intensive field of study. In this work, a two-dimensional (2D) ‘mass-in-mass’-spring lattice system is utilized to achieve anisotropic effective mass density in two orthogonal principal directions.In each direction, the effective mass density is frequency-dependent and can be “effectively negative” if it falls within the frequency bandgap region. A 2D numerical continuum model,based on a recently developed cantilever-in-mass model, is further presented and examined to study how wave input angles affect 2D wave propagation. Results show that wave attenuation is dependent on both input frequency and wave input angle in a 2D metamaterial. This study demonstrates a case whereby wave attenuation is achieved,by selecting wave input frequency in the bandgap region to enact “negative effective mass density”. This study also illustrates another case when wave attenuation is obtained for positive anisotropic mass density. This behavior is achieved by directing wave propagation to transverse direction at a specific input wave angle of 60°. Both numerical calculations of mass-spring lattice model and continuum cantilever-in-mass model show good agreement.
The role of segment probability in perception of speech sounds
Authors: Park Seongjin , Hoffmann Maureen , Shin Priscilla Z. , Warner Natasha L.
Published: April 2018

This study investigates how listeners utilize segment probability in speech perception. In Warner et al. (2014), participants identified gated fragments of all combinations of two segments in English (e.g., diphones /hə/, /dt/, /ab/, /iɛ/). That data was further analyzed to study the influence of segment probability. Overall probability of the second segment (e.g., the probability of /t/ in English), and conditional probability of the second segment given the first segment (e.g., the probability of /b/ given preceding /a/) were calculated from the CMU pronunciation dictionary. There were significant correlations between accuracy of segment perception and both overall and conditional probability of second segments at early gates of the diphone, when few or no acoustic cues to the second segment were available (for example, perception of /b/ in /ab/ by one-third of the way through the /a/). However, when participants had enough acoustic information, the correlation was smaller or non-significant. The present study shows that English listeners utilize probability in identifying English segments when few acoustic cues are available, whereas Dutch listeners in a matched previous study on perception of Dutch (Warner et al. 2005) utilized probability only for a few unusual cases.
Semantic context modulates intelligibility advantage of clear speech in temporally compressed sentences
Authors: Shafiro Valeriy , Smiljanic Rajka , Keerstock Sandie
Published: April 2018

Sentences produced in a clear speech speaking style are typically more intelligible than sentences produced in a conversational style. However, factors that lead to the intelligibility difference are not fully understood. This study investigated the role of semantic context in intelligibility of temporally compressed clear and conversational speech. Grammatically correct English sentences, which were either semantically meaningful or semantically anomalous, were presented to 70 normal-hearing listeners in clear or conversational speaking style. The sentences were temporally compressed to produce seven different syllabic rates (6-12), matched across clear and conversational sentences to control for the original durational differences between clear and conversational speech. Results for semantically anomalous sentences indicate no differences in the rate of intelligibility decline across compression rates for clear and conversational speech. In contrast, for semantically meaningful sentences, the rate of intelligibility decline was smaller for the semantically meaningful clear-speech sentences over semantically anomalous conversational-speech sentences. At the highest compression rate of 12 syllables per second, intelligibility of semantically meaningful clear-speech sentences (~68% correct) was similar to that of semantically anomalous sentences at 9 syllables per second. These findings suggest that semantic context can modulate the effect of speaking style on the intelligibility of temporally compressed sentences.
Musical training and the perception of phonetic detail in a shadowing task
Authors: Tsang Grace Ji Yan , Dana Edmund L. , Farbood Morwaread M. , Levi Susannah V.
Published: April 2018

Phonetic convergence, or shadowing, is the phenomenon in which people unintentionally and temporarily change phonetic details of their speech to sound more similar to another talker. Previous research has examined effects of the shadower and of the target speaker. In the current study, we examine listener contributions on the perception of phonetic convergence. Two hundred and sixty listeners completed an AXB perception task in which they were asked to determine whether the first or third stimulus was a better imitation of the middle stimulus. Listeners provided information about previous instrumental and vocal training. Preliminary examination of the results reveals that listeners with more musical training (in the form of instrumental or vocal experience) lead to better accuracy. Results from the study suggest that there is a link between musical training and detection of fine-grained phonetic details in speech.
Power and phonetic accommodation
Authors: Lutzross Auburn , Cheng Andrew , Shen Alice , Wilbanks Eric , Mirzaagha Azin
Published: April 2018

Theories of speech accommodation claim that phonetic convergence to one’s interlocutor is automatic (Goldinger, 1998; Shockley et al., 2004). However, there is evidence that individual traits and social factors modulate accommodation so that speakers may even diverge from their interlocutor (Babel, 2010; Bourhis & Giles, 1977). This study investigates how talker’s personal sense of power and power relative to the interlocutor (“interpersonal power”) affect phonetic accommodation. Personal power was manipulated through a thought experiment in which participants described a time they felt powerful or powerless. Interpersonal power was manipulated through randomly assigned roles in a recorded interview with a confederate where the Inventor (powerless) pitched an entrepreneurial idea to the Investor (powerful). Participants were considered to have converged if the difference in pitch between the participant and confederate had decreased in post-interview versus pre-interview recordings. We found that though interpersonal power does not influence the direction or degree of accommodation, personal power does. Speakers with lower personal power diverged from their interlocutor (t = -2.1389, p = 0.04), indicating that an individual’s self-perception has a stronger effect on accommodation than the established roles in the interaction.
Impact of talker adaptation on speech processing and working memory
Authors: Lim Sung-Joo , Tin Jessica , Shinn-Cunningham Barbara , Perrachione Tyler K.
Published: April 2018

Talker adaptation is known to facilitate immediate speech recognition. However, it is unclear whether and how talker adaptation also facilitates working memory for speech. Using electroencephalography (EEG) during a delayed recall of digit span task, we investigated whether talker adaptation facilitates working memory performance. We also investigated whether neural alpha oscillatory power reflects facilitatory effects of talker adaptation. Listeners encoded sequences of seven randomly ordered digits, recalling them after a 5-s retention. Digit sequences were spoken by either a single talker or multiple talkers, and were presented at either faster or slower speech rates (0-ms vs. 500-ms inter-digit intervals). Overall, listeners responded faster and more accurately for single-talker sequences compared to multiple-talker sequences. Especially for the faster presentation rate, listeners were more efficient (faster and more accurate) in recalling sequences spoken by a single talker. For the faster presentation rate, processing digit sequences spoken by single vs. multiple talkers also elicited reduced alpha power during both speech encoding and working memory retention. These results suggest that talker adaptation reduces cognitive effort during both speech encoding and memory retention, thereby producing more efficient working memory for speech information, especially when listeners process speech rapidly.
Gender typicality in children's speech, reconsidered: Effects of stimulus composition on listener judgments
Authors: Beaulieu McKalya , Larson Emily , Munson Benjamin
Published: April 2018

Listeners rate the speech of boys and girls as young as four years old as sounding gendered: boys are rated as sounding boy-like and girls as girl-like (Perry et al., J. Acoust. Soc. Am. [2001]). Recent research found that the extent to which boys’ speech sounds boy-like is correlated with measures of their gender identity and expression (Li et al., J. Phonetics [2016], Munson et al., J. Acoust. Soc. Am. [2015]). Munson et al. found that boys with a diagnosis of gender identity disorder [GID] were rated as sounding less boy-like than boys without GID. Munson et al.’s experiment used only a small number of girls’ productions as filler items. The current study examined listeners’ ratings of the gender typicality of speech of boys with GID and both boys and girls without GID. Significant differences in sex-typicality ratings were found between the two groups of boys. Boys with GID elicited ratings intermediate to those for boys and girls without GID. However, the differences between boys with and without GID were much smaller than those in Munson et al., suggesting that the sex distribution in the stimulus set can affect ratings of the sex typicality of children’s voices.
Children’s ability to benefit from fundamental frequency and vocal tract length differences during speech-in-speech recognition
Authors: Flaherty Mary M. , Leibold Lori , Buss Emily
Published: April 2018

The present study evaluated whether children’s speech-in-speech recognition benefits from differences in fundamental frequency (F0) or vocal tract length (VTL) between the target and masker talkers’ voices. Children, like adults, can benefit from a sex mismatch between competing talkers, but the relative contribution of individual voice characteristics to children’s improved speech-in-speech understanding is unknown. In this study, we first tested children’s ability to use differences in either F0 or VTL between target and masker speech to evaluate the independent influence of these cues on speech-in-speech recognition. Then F0 and VTL differences were combined to determine whether cue redundancy would reduce the child/adult differences observed in these contexts. Sentence recognition thresholds were measured in a two-talker speech masker. All stimuli were recorded by the same female talker. F0 and VTL of the target sentences were manipulated using the pitch-synchronous overlap-add method. Preliminary results suggest a prolonged developmental trajectory in the ability to use F0 or VTL in isolation, but indicate that the combination of these cues benefits children at an earlier age compared to when either cue is presented in isolation. Adults showed the greatest benefit from the F0-only manipulation, showing no additional benefit when F0 and VTL were combined.
Clot stiffness is inversely correlated with rt-PA thrombolytic efficacy in vitro
Authors: Mercado-Shekhar Karla P. , Kleven Robert , Aponte Rivera Hermes , Lewis Ryden , Karani Kunal B. , Vos Hendrik J. , Abruzzo Todd A. , Haworth Kevin J. , Holland Christy K.
Published: April 2018

Predicting thrombolytic susceptibility to recombinant tissue plasminogen activator (rt-PA) a priori could help guide clinical decision-making during acute ischemic stroke treatment and avoid adverse off-target lytic effects. The composition and structure of clots impact their mechanical properties and rt-PA thrombolytic efficacy. The goal of this study was to determine the relationship between clot elasticity and rt-PA thrombolytic efficacy in vitro. Human and porcine retracted and unretracted clots were fabricated in glass pipettes. Clots were embedded in agar phantoms, and their Young’s moduli were estimated using single-track-location shear wave elasticity imaging. The rt-PA thrombolytic efficacy was evaluated in vitro using the percent clot mass loss. The Young’s moduli of unretracted porcine and human clots (1.68±0.18 kPa and 0.72±0.13 kPa, respectively) were significantly lower (p<0.05) than those of retracted porcine and human clots (4.96±1.07 kPa and 3.38±1.82 kPa, respectively). The percent mass loss of unretracted porcine and human clots (28.9±6.1% and 45.2±7.1%, respectively) were significantly higher (p<0.05) than those of retracted porcine and human clots (10.9±2.1% and 25.5±10.0%, respectively). The results revealed a linear inverse correlation between the Young’s moduli and percent clot mass loss (R2 = 0.95, p = 0.025), suggesting that clot stiffness may serve as a surrogate metric for rt-PA thrombolytic susceptibility.
Simulation and analysis of three-dimensional echo decorrelation imaging
Authors: Cox Michael T. , Abbass Mohamed A. , Mast T. Douglas
Published: April 2018

A numerical model for pulse-echo ultrasound imaging [Mast, JASA 128:EL99-EL104, 2010] is extended to three-dimensional (3D) imaging of linear, weakly scattering continuum media by matrix array transducers. In this model, beam patterns for steered transmit and receive subapertures, calculated analytically under the Fresnel approximation, are combined with a 3D numerical tissue model to yield beamformed scan lines in a rectilinear or pyramidal configuration. Simulated scan lines are processed to yield both volumetric B-mode images and echo decorrelation images, comprising spatial maps of the normalized decorrelation between sequential pulse-echo image volumes. A method is demonstrated for construction and scan conversion of quantitative 3D echo decorrelation images such that, as for 2D echo decorrelation imaging [Hooi et al., JASA 137:585-597, 2015], the mapped echo decorrelation consistently estimates the local decoherence spectrum of the tissue reflectivity. Simulated 3D echo decorrelation images of random media are shown to accurately estimate known decoherence distributions that simulate heating effects in thermal ablation. Effects of factors including transducer frequency, scan configuration, and simulated lesion size on accuracy of decoherence estimates are tested. Applications to 3D monitoring of radiofrequency and microwave ablation are discussed.
Travelling by microphone—The origami of time- and level-based effects
Authors: Pastore M. Torben
Published: April 2018

The introduction of the microphone brought radical transformations to vocal technique—consider the transition from Bel Canto to crooning. This radically changed the relation between the singer and the backing band or orchestra. More importantly, the singer could now appeal intimately to the listener with all the directness and art of a whispering lover, but with the full backing of the band for sympathy, illustration, and reverie. With the introduction of mutitrack recording and sound reinforcement, artists could bring their listeners closer, even behind their eyes, or hold a space for listeners to relate to themselves, by presenting multiple spaces with multiple actors at multiple distances simultaneously. The simple use of microphones, delays, reverbs (modulated and not), compression, and other effects to say what cannot be said with time and space-bound forms where the relations between musicians, singers and listeners are defined and constrained by the single space they share will be considered. The manifestation of the psychedelic/deep listening experience as a transform, via simple time- and level-based effects, of music into experience grounded in actual, unknowable reality will be considered and auditioned.
Guitar amplifier modeling—Perceptual evaluation of audio similarity
Authors: Eichas Felix , Zoelzer Udo
Published: April 2018

Virtual analog modeling of guitar equipment, especially tube-based guitar amplifiers, is a hot topic in sound effect research. However, there are no established standards on the evaluation of the accuracy of such modeling processes. This work presents a first approach on finding a metric for evaluating the similarity between the output of an analog reference amplifier and a digitized version of the same device. A gray-box modeling procedure is used where only assumptions about the general structure of a guitar amplifier are made. The necessary information about the reference device is obtained by input and output measurements. First a digital model is constructed and the error between digital model and analog system is minimized by the Levenberg-Marquardt parameter optimization algorithm. The error is expressed as the result of a cost function. To be able to produce good results, this cost function needs to consider psycho-acoustic aspects like e.g. the perceived frequency resolution. The results of a spectrogram based cost function are compared to the results of a listening test, where the test subjects should rate the similarity of the two audio signals (reference and digital simulation) and the findings are discussed.
The use of physical and artificial room reverberation to create transparent or fused ensemble sounds
Authors: Braasch Jonas
Published: April 2018

Room Reverberation has shaped the sound of musical instruments from the beginning. The oldest known musical instrument, a 40,000-year-old bone flute has been found in a cave, the Hohle-Fels Hoehle. Impulse response measurements taken at this cave reveal that the cave had a reverberation time, T30, at mid frequencies of 1.8 seconds, a value within the range of that of a modern concert hall. Room reverberation has continued to play an important role in defining our cultural sonic environments. During the Reformation, for example, there was a clear call for transparency so that the words of the reverends could be understood by the people. This sound ideal also affected the music of protestant composers like Johann Sebastian Bach an ideal that culminated in the interpretations of Glenn Gould, who preferred the natural sound of the dry sound recording studio. While a concert hall is always bound to its sound, most modern recording studios offer a flexible design where the room can be created artificially around the artist to achieve a certain sound ideal. Unlike in a physical hall that embeds all musicians in a homogenous sound, artificial reverb is often used to provide a unique environment for each instrument to meet specific goals.
Correlation between perception and acoustical parameters in five musical genres
Authors: Bader Rolf
Published: April 2018

To investigate the influence of sound effects on the perception of musical genres, excerpts from 150 musical pieces of Rock, Jazz, Classical, Ethnographic and Electronic music were compared. In a listening test subjects were asked to judge them in terms of 12 adjectives related to spaciousness, timbre and semantic attributes. Additionally the pieces were analyzed with three methods. To judge the spaciousness the Interaural Cross Correlation (IACC) was calculated. To estimate the audio effect strength an echodensity was defined as the amount of phase fluctuations. To estimate the density of tonal texture a fractal correlation dimension was used. The musical genres clearly sorted along their IACC values with Rock being most ‘mono’ and Classical music most spatial. The echodensity was about the same for all genres except for electronic music where it was considerably larger. The mean fractal correlation dimensions were about four with all genres pointing to a mean textual density for all genres. In terms of perception, the higher echodensity correlated positively with the adjective “artificial” for Electronic music. Additional findings were made.
Sound effects without side effects—Suppression of artifacts in audio signal processing
Authors: Case Alexander U.
Published: April 2018

Sound effects processes intending one production outcome can too often be accompanied by unwanted side effects. Signal processing strategies have evolved in popular music production that preserve a producer’s sonic goals while suppressing these artifacts. The solutions found can be surprising and frequently have no analog in all-acoustic music creation and presentation. Sound effects with these built-in defense mechanisms become studio-only creations, effects for loudspeaker mediated art only.
Preference, localization, attention, and the limit of localization distance (LLD)
Authors: Griesinger David H.
Published: April 2018

Recent work by Lokki et al. has found that a perception he calls “proximity” is a major component of preference in concert halls. In this talk we propose that proximity is perceived when sources are close enough or clear enough that they can be sharply localized and understood. In halls and rooms we find this ability abruptly disappears at a critical distance from the source, the Limit of Localization Distance, or LLD. We find that proximity attracts and holds attention, which is a major reason cinemas and drama theaters have dry acoustics and strong direct sound paths. In this talk we will describe the physics behind the perception of proximity, why it has not been previously recognized, how to predict where the LLD will occur from a binaural impulse response, and how to optimize proximity in halls, theaters, and classrooms.