bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical inference for sediment parameters using ship noise and a horizontal array
Authors: Tollefsen Dag , Knobles David P. , Dosso Stan E.
Published: November 2017

This paper considers the use of broadband noise from ship sources of opportunity in statistical inference for geoacoustic parameters of a layered seabed, with applications to data collected with a bottom-moored horizontal array in the 2017 Seabed Characterization Experiment conducted on the New England Shelf. Statistical inference via a maximum entropy—Bayesian approach that determines the most appropriate model parameterization (number of seabed layers) and provides uncertainty estimates of all model parameters (sediment geoacoustic profiles) is applied. The geoacoustic information content of noise due to large commercial ships in a nearby shipping lane and of noise due to a research vessel traversing the array is quantified and compared. Parameter estimates from the inversions are compared with direct measurements from sediment cores and other geophysical data collected in the experiment area.
Finding an appropriate headphone-based stereo track playback methods by referencing acoustic characters of professional recording studios
Authors: Nam Myoung woo
Published: November 2017

Most Red Book CD or streaming 2-track music mixed and mastered in a professional recording studio. However, headphone listener experience different to its original studio condition. The recent headphone has decent frequency response, but the sounds do not match especially in soundstage (width and depth of music mix in a horizontal plane) perspective. Although Recording studios are designed to minimize unwanted reflections and resonances, every studio has its own room characteristics of natural room frequency response. In other words, “the acoustical room characteristic” added on “finalized mix” is the real representation of the mastered 2-track music. In this paper, we tried to find the ultimate headphone-based listening methods by referencing the professional recording studios.
Acoustics of the tense-lax stop contrast in Semarang Javanese
Authors: Seyfarth Scott , Vander Klok Jozina , Garellek Marc
Published: November 2017

Javanese has a contrast between tense and lax stops. While both tense and lax stops are voiceless and unaspirated, the contrast at least in word-initial position is realized through acoustic differences in the following vowel, including lower f0, breathier voice quality, and higher F1 for the lax stops relative to their tense counterparts. However, previous reports have indicated substantial cross-speaker variation, and in some cases involve differing characterizations of the acoustic contrast, possibly due to small sample sizes. Moreover, it is still unclear whether (and how) this contrast is maintained in word-final position. In this study, we investigate the tense-lax contrast based on audio recordings of 27 speakers of Central Javanese from Semarang, Indonesia who each read 30 or more items with a word-initial or word-final stop in a carrier phrase. Stops and their adjacent vowels were hand-annotated, and measurements were taken including voice onset and offset time, stop closure and release duration, f0, formant frequencies, and spectral tilt and noise levels. Discussion will focus on how the tense-lax contrast is realized in both word-initial and word-final positions, as well as how different acoustic correlates co-vary within and across speakers.
Pause postures in American English
Authors: Krivokapic Jelena , Styler Will , Parrell Ben , Kim Jiseung
Published: November 2017

Recent work examining articulation during pauses has found that articulatory patterns distinguish grammatical from ungrammatical pauses (Ramanarayanan et al. 2009). For Greek, Katsika et al. (2014) have identified pause postures (specific configurations of the vocal tract at prosodic boundaries) which are triggered by π-gestures with high activation levels and consequently occur at strong prosodic boundaries. This study investigates pause postures in American English, specifically, whether they occur, and how they are coordinated with other events at prosodic boundaries. In an electromagnetic articulometry (EMA) study, seven speakers produced 7-8 repetitions of 42 types of sentences varying in linguistic structure (stress, boundary, phrasing, and sentence type). Results from two speakers analyzed to date indicate that pause postures exist but that their presence might be speaker dependent. Analyses of gesture lags indicate a stable relationship between the boundary tone and pause posture, that the boundary tone gesture starts later when stress is on the second syllable, and that the π-gesture is shifted towards the stressed syllable, parallel to findings in Katsika et al. (2014). We discuss these results in relation to models of prosodic structure and to speech planning processes. [Work supported by NIH and NSF.]
Spatial-division-multiplexing in time-variant and multi-path channel based on vector adaptive time reversal technique
Authors: Lu Dian , Sheng Xueli , Shi Yali , Yu Hanjun , Guo Longxiang
Published: November 2017

In the field of multistatic remote detection for underwater target, as a time-variant and multi-path channel interfered by environmental noise, complex underwater acoustic environment limits the spatial share of channel and poses a great challenge against spatial-division-multiplexing (SDM) in multistatic detection. In this paper, a kind of method of spatial-division-multiplexing(SDM) based on vector adaptive time-reversal technique is proposed. By use of time-reversal technique, multi-path structure of channel is efficiently restrained; Meanwhile, with adaptive filtering applied, time-variant characteristic of channel is effectively suppressed. Moreover, with single vector hydrophone, spatial focus of target echoes and noise interference suppression is accomplished by spatial filtering. Finally, excellent results are performed in SDM of multistatic detection, supported by the experimental simulation.
Double-difference tracking of bowhead whales using unsynchronized directional acoustic recorders in the Beaufort Sea
Authors: Tenorio-Hallé Ludovic , Thode Aaron , Blackwell Susanna B. , Kim Katherine H.
Published: November 2017

Passive acoustic monitoring has become a standard method for detecting bowhead whale (Balaena mysticetus) activity in Arctic waters. Between 2007 and 2014, over 40 directional acoustic recorders, known as DASARs, were deployed in the Beaufort Sea during the bowhead whale migration season. Individual DASARs can estimate azimuth, allowing calls to be localized by triangulation using multiple DASARs. However, these bearings are subject to calibration biases, and individual recorders were not precisely time-synchronized, making relative time-of-arrival information unusable for standard localization purposes. Double-difference methods have previously been applied in seismology to obtain high-precision relative positions of earthquakes by measuring changes in relative travel-times between multiple events over widely distributed seismic sensors. Here, the double-difference method is applied to detected bowhead whale calls in order to improve the relative localization resolution. The approach uses changes in both relative call travel-times and bearings, detected at multiple DASARs, to determine high-precision relative locations of these calls despite the presence of systemic timing and bearing errors in the measurements. The resulting positions allow tracking of individual whales, which may provide insight into the function of these calls.
Detection and localization of weak impulses and continuous sources within the urban acoustic environment
Authors: Haskins Richard , Simpson Christopher , McKenna Mihan H.
Published: November 2017

Signal detection and localization with large aperture acoustic arrays in urban environments can be inherently difficult. This poster presents some preliminary approaches under investigation for; determining the direction of arrival of continuous sources that are changing in frequency, detecting and localizing low signal to noise ratio impulses in the presence of coherent background noise, and a fast mapping approach for converting array element delays to direction of arrival using a neural network fitting function. For uniform circular array geometries with a central reference array element, the direction of arrival of sources with changing frequency can be visualized by applying the Hilbert transform and analyzing the relative phase angle rate of change of the outer array elements. Next, various computational approaches for low level impulse detection in the presence of coherent acoustical noise are presented. Last, a neural network fitting function is discussed that performs array specific delay mapping to direction of arrival with high computational efficiency and trained noise immunity.
Geophone and tetrahedral array measurements in the New England Mud Patch and preliminary results
Authors: Potty Gopu R. , Miller James H , Aggarwal Poonam , Aggarwal Nipun , Lin Ying-Tsong , Newhall Arthur
Published: November 2017

Measurements of acoustic pressure and particle velocity were made during the Seabed Characterization Experiment (SCEx) in the New England Mud Patch south of Cape Cod in about 70 meters of water. The University of Rhode Island and Wood Hole Oceanographic Institution deployed the “geosled” with a four-element geophone array, a tetrahedral array of four hydrophones and several hydrophone receive units (SHRUs). In addition, a new low frequency source, interface Wave Sediment Profiler (iWaSP) was deployed to excite interface waves. The iWaSP system consists of a source to generate the interface wave and a four-element accelerometer receive array. The range between the iWASP and geosled was about 100 meters. Examples of data collected during the experiments will be presented. Preliminary results of the acoustic and particle velocity data will be discussed. Preliminary analysis of the data and approximate initial estimates of the seabed properties will be presented. [Work supported by Office of Naval Research.]
Preliminary analysis of geophone and tetrahedral array data from the Seabed Characterization Experiment
Authors: Aggarwal Poonam , Aggarwal Nipun , Potty Gopu R. , Miller James H , Lin Ying-Tsong , Newhall Arthur
Published: November 2017

As part of the Seabed Characterization Experiment (SCEx), the University of Rhode Island and Wood Hole Oceanographic Institution deployed the low frequency shear measurement system and the interface Wave Sediment Profiler (iWaSP) system in the New England Mud Patch south of Cape Cod in about 70 meters of water. Multiple sensors were utilized to collect data which include a geosled with a geophone array of four vertically gimbaled geophones and a tetrahedral array of four hydrophones. The iWasp was used for exciting the interface waves. The iWaSP system was deployed from the R/V Sharp and it transmitted 10 seconds chirp signals every one minute between 33 and 200 Hz. The geophone array was approximately 100 m from the iWaSP source. Detection of the chirps from geophone and tetrahedral array signals was challenging due to the presence of noise sources such as ship traffic and environmental noise. Data were explored for the presence of iWaSP chirp signals in the audio and further analyzed using techniques such as matched filtering. The preliminary results and initial hypothesis regarding the wave types corresponding to the multiple arrivals will be presented. [Work supported by Office of Naval Research.]
Geoacoustic inferences from seabed reflection measurements on the New England mud patch
Authors: Holland Charles W. , Smith Chad M. , Belcourt Josée , Dosso Stan E.
Published: November 2017

The vast majority of sediment acoustics research has been aimed at understanding propagation in granular (sandy) sediments. The focus of the ONR Seabed Characterization Experiment was to improve understanding of fine-grained/cohesive sediments. A variety of measurement techniques by various researchers were conducted to that end. Here, we report on initial results from broadband wide-angle reflection measurements at two sites, one with a ∼2 m “mud” layer thickness and the other ∼11 m thick. The measured reflection coefficient exhibits features that permit estimation of geoacoustic properties including the critical angle (with a rather weak frequency dependence, 200-2500 Hz) and interference patterns in frequency-angle space (which provide information on properties in individual layers). Modeling permits insight into the information content of the data and some initial estimates of the geoacoustic properties. [This research was funded by the Office of Naval Research, Ocean Acoustics Program.]
Characterization of mud sediments using the frequency dependence of phase velocity and attenuation of compressional waves
Authors: Pierce Allan D. , Siegmann William L. , Brown Elisabeth M.
Published: November 2017

The present paper’s theory predicts phase velocity and attenuation for mud sediments that contain silt particles, and is based on the model of a suspension consisting of solid particles dispersed in a viscous liquid; the attenuation expression dates back to Lamb's Hydrodynamics and to Urick (JASA, 1948), clarified and rederived by Pierce, Siegmann, and Brown (POMA, 2017). The application to mud is based on the premise that silt particles are held in suspension by the loosely connected matrix of clay particles and that their natural oscillation frequencies are significantly less than the frequencies used in underwater acoustics. The present paper extends that theory with a fresh derivation based on concepts of matched asymptotic expansions and results in an expression for the complex wave number k as a function of the angular frequency. The results for phase velocity disagree with results published in the past by Ahuja (JASA, 1972) and Temkin (JASA, 2000). The assertion is made that the use of the theoretical predictions will enable one to deduce mud sediment properties such as porosity, fraction of volume that is suspended particles, and representative grain sizes from measurements of frequency dependence of sound speed and attenuation. [Work supported by ONR.]
Bayesian inference and model selection to investigate seabed shear-wave velocity profiles via interface-wave dispersion inversion
Authors: Dosso Stan E. , Dong Hefeng
Published: November 2017

This paper applies a general geoacoustic profile parameterization based on Bernstein polynomial basis functions to consider the form of seabed shear-wave velocity profiles via Bayesian inversion of interface (Scholte) wave dispersion. Theory and observations indicate that the shear-wave velocity profile of seabed sediments of uniform composition and density often corresponds (approximately) to a power law function of depth. Hence, past inversions have often been based on a power-law parameterization without considering independently if this form is actually required by the data. The Bernstein parameterization, based on a linear combination of Bernstein-polynomial basis functions with the polynomial order determined by the Bayesian information criterion, is general and allows the form of the profile to be determined by the data, rather than by a subjective prior choice. In this paper, measured-data inversions are compared for power-law, Bernstein-polynomial, and layered trans-dimensional parameterizations to investigate the shear-wave velocity profile form.
Applications of a suspension theory of silt particles in mud to frequency and other parameter dependencies of geoacoustic quantities
Authors: Brown Elisabeth M. , Pierce Allan D. , Chaytor Jason D. , Lin Ying-Tsong , Siegmann William L.
Published: November 2017

A recent suspension theory of marine mud [Pierce, et al., POMA 29, accepted] hypothesizes that embedded silt particles are the dominant contributors to compressional wave attenuation. The approach predicts frequency intervals within which attenuation increases roughly linearly with frequency, as often assumed. These intervals depend on the measured (or assumed) mean silt particle size. This presentation investigates the influence of distributions of silt particle sizes on attenuation, including the distribution shapes obtained from data, and the intervals of linear frequency with multiple particle sizes. In addition to attenuation, the theory also provides compressional sound speed predictions. Their sensitivity to changes in measured physical parameters and frequency will be determined, and the results compared with archival data and recently analyzed SBCEXP core data along a range-dependent experimental track. Another consequence of the theory is how porosity is affected by the minimum separation distance between silt particles and including viscous boundary layers. An environmental-acoustic model of the experimental track will be constructed, based on ocean sound-speed profiles, bathymetry, analyzed core data, and attenuation from theory. This model will be used to calculate transmission loss for propagation along the track to compare with acoustic measurements from the experiment. [Work supported by ONR.]
Study on influence factors of popular Chinese restaurants
Authors: Zhou Yude , Zhang Weichen , Shao Zhiyue , Zhu Wenying
Published: November 2017

There are great differences in restaurant soundscape between China and the United States, as Chinese people prefer to be engaged in an animated conversation during dining. This study emphasizes on revealing the relationship between restaurant soundscape and local culture, dining custom and restaurant arrangement, etc., and identifying the unique characteristic of the restaurant soundscape in China. Typical Chinese restaurants are selected to investigate the dining culture in China, and to further analyze the relationship between Chinese restaurant soundscape and people’s opinion toward it by both objective and subjective soundscape parametric study. It is shown that the high sound pressure lever, for instance, 70–80 dBA in dining lobby with capacity crowd, in Chinese restaurant is mainly due to a long reverberation time. Meanwhile, since dining in restaurant is regarded as a popular social activity, and people like to gather in a restaurant and chat merrily when dining, the larger table people sit by, the louder voice people have to speak in. It is also found that for the most of the time, people enjoy in the conversation, not bothered by the high sound pressure level, and if a silent dining environment is required, a private room is often available. Therefore, there is a close connection between the local culture and restaurant soundscape in China, of which better understanding can be obtained only if you are involved in.
Case studies that explore the soundscape of dining
Authors: Siebein Keely , Siebein Gary W.
Published: November 2017

The acoustics of restaurants is related to the soundscape of dining. The goal of this study is to better understand and document the soundscape of dining as a method to analyze communication paths among diners. This will be used to determine possible acoustical interventions based on the perceived acoustical qualities of the spaces by the local experts, i.e., diners, staff, and operators of the facilities. This study compares case studies of three restaurants using the soundscape method to explore links between qualitative evaluations of the soundscape by users, staff, and operators of the facilities and acoustical metrics including analysis of impulse response measurements between occupants in the rooms, and acoustical measurements calculated from the impulse responses including STI and RT. Using the soundscape methods, along with impulse response measurements based on actual communication paths, allows for diagnosis of surfaces to be treated and allows acoustical metrics to be derived that reflect the qualitative analysis of the space as it is heard by diners, staff, and owners of the restaurants.
Sound pressures generated by exploding eggs
Authors: Nash Anthony , von Blohn Lauren
Published: November 2017

Manufacturers of microwave ovens caution people to avoid re-heating certain food products because the rapid heating process can pose a danger to the user. Examples of such products are potatoes and eggs. Heating a potato in a microwave can generate steam under pressure. The internal steam pressure induces high tensile stresses in the potato skin, sometimes leading to its sudden (and unpredictable) bursting. A re-heated hard-boiled egg can also explode unpredictably but its bursting mechanism works differently than the potato. It is now believed that the egg yolk develops many small pockets of superheated water, leading to an increasingly unstable condition. When the egg yolk is disturbed by an internal or external stimulus, the pockets spontaneously boil, thereby releasing considerable energy (i.e., an explosion). An acoustical investigation was conducted using nearly 100 eggs that were re-heated under controlled conditions in a calibrated microwave oven. About a third of the re-heated, boiled eggs exploded outside the oven. For those eggs that did explode, their peak sound pressure levels ranged from 86 up to 133 decibels at a distance of 300 mm. The paper will describe the test protocols and discuss the results.
Exposure-induced changes in laboratory mouse ultrasonic vocalizations
Authors: Burke Kali , Screven Laurel A. , Dent Micheal L.
Published: November 2017

Mouse ultrasonic vocalizations (USVs) have been categorized by researchers based on their variable spectrotemporal features, including frequency, intensity, and duration. These USVs may be important for communication, but it is unclear whether the categories that researchers have developed are relevant to mice when trying to understand their USVs, or if it is other properties such as the number, rate, peak frequency, or bandwidth of the calls that are significant. The current study aims to create a comprehensive catalog of the USVs that mice are producing in order to better understand if and how these animals are using their USVs for communication. Forty male and female adult CBA/CaJ mice were recorded for five minutes following either a one-hour period of isolation or exposure with a same- or opposite-sex mouse. Vocalizations were categorized into nine categories and quantified based on the bandwidth, duration, peak frequency, and total number of calls across those categories. There were significant differences in how mice produced their vocalizations when they were alone compared to following a social encounter. Further, this study provides critical data from female mice producing calls, an often overlooked phenomenon in mouse vocalization research.
The whistled source of Gibbon vocalizations
Authors: Yu Shi , Demolin Didier
Published: November 2017

Gibbons vocalizations are often referred to as “songs” because of their pitch modulations. The elements composing Gibbons vocalizations are often called notes. Here, we discuss how they are generated. The audio waveform of some characteristic song notes of gibbons (espèce) show that they are produced with a high fundamental frequency (F0), often above 500 Hz, and a set of harmonic components. The F0 of these notes can also be modulated across large intervals of pitch. Spectrograms and the shape of the audio waveform suggest that they are the outcome of a whistled source. This is confirmed by the observation of audio wave from which is not complex. This also explains why there are no formants in most of their vocalizations. The high F0 source makes that the distance between harmonics and the short vocal tract length prevents the presence of resonance modes. One way to explain this whistle source is to consider that the airflow passes through stiff nonvibrating vocal folds. This setting also suggests that pitch modulations of Gibbons songs might be produced by changing the vocal folds length during their vocalizations. The effect of this change in length is increase or decrease F0.
Song bird vivaria considerations
Authors: Barnobi Christopher L. , Snyder Katherine , Creanza Nicole
Published: November 2017

The design of laboratory animal vivaria should include consideration of factors that may impact the results of intended experiments. Two examples where the acoustic environment of birds could significantly affect experimental results include (1) song learning accuracy in isolated juvenile songbirds and (2) the preferences for bird songs by mates. We conducted a detailed analysis of a proposed vivarium design in a laboratory setting to assess important acoustical factors. We analyzed vivaria for room acoustics and sound isolation properties. Sound isolation and reverberation were primary concerns since bird song learning accuracy was an aim of the laboratory research. The environments are planned to be used to research juvenile birds learning a single model song during development. We tested the effects of treating the vivaria with sound absorbing foam, including the reverberation in enclosures and associated impacts on results comparing recorded bird songs. In addition, we tested the existing background sound levels observed in the laboratory and the sound isolation properties of the vivaria. Sound isolation results for the initial isolated environments shows transmission loss values from the exterior to the interior of the vivaria were significantly less than the expected 30 dB. Reverberation results reveal a distinct reduction when the interior of the vivarium enclosures were treated with a sound absorber.
Simulated anthropogenic noise exposure to marine invertebrates using a standing wave tube
Authors: Dossot Georges , Krumholz Jason , Hudson David , Pochtar Darby
Published: November 2017

The experimental design of a standing wave tube suitable for monitoring the impact of anthropogenic noise upon marine invertebrates is presented. Human usage of coastal water bodies continues to increase and many commercially harvested invertebrates face a broad suite of anthropogenic stressors (e.g., warming, pollution, acidification, and fishing pressure). Underwater noise is one such stressor that exists in coastal areas, but the potential impact on invertebrates, including sublethal effects such as masking, behavioral, and physiological impacts, is not well understood. A major obstacle to further progress in this field is that in-situ experiments using high sound levels require extensive permitting and can be difficult to monitor, while ex-situ laboratory experiments do not often account for acoustic artifacts likely present in closed tank environments. We demonstrate the design and implementation of a relatively inexpensive standing wave tube approach, which creates a uniform sound field large enough to allow simultaneous exposure of multiple invertebrates per trial. We exposed juvenile and sub-adult blue crabs (Callinectes sapidus) and American lobsters (Homarus americanus) to simulated low-frequency boat noise and mid-frequency sonar, and measured behavioral and physiological responses, as well as acoustic pressure and particle motion to fully quantify the impacts of the sound field.
Opportunistic underwater recording of what might be a distress call of Chelonya mydas agassizii
Authors: Cordero Tapia Amaury , Vivas Eduardo
Published: November 2017

All around the world, sea turtles are considered endangered species since their population has declined in the last two decades. In Baja California Sur Mexico, there is a conservation program run by Government Authorities, Industry, and Non-Governmental Agencies focused on vulnerable, threatened, and endangered marine species. In zones of high density of sea turtles, special nets, which allow them to surface for breathing, are deployed monthly for monitoring purposes. Nets are checked every 2 hours during the 24 hours of the census. During one of these checks, a female specimen of Chelonya mydas agassizii was video recorded using an action cam. Posterior analysis of the recording showed a clear pattern of pulsed sound when the diver was at close proximity to the turtle. The signal covers a frequency range of 300 to 800 Hz, which is within the ABRs average audiogram range reported by Ketten and Bartol for Chelonya mydas and within the behavioral Audiogram for Chelonya mydas agassizii that we have previously reported. The video and the sound analyses of this opportunistic recording, which might be a distress call, are presented.
Semi-analytical finite-element based method for inverse characterization of cortical bone using low-frequency guided waves
Authors: Pereira Daniel , Fernandes Julio , Belanger Pierre
Published: November 2017

Axial transmission research has demonstrated that low-frequency ultrasonic guided waves are sensitive to changes in the intracortical bone, which is of interest since the resorption in the endosteal region is associated to early-stage osteoporosis. Current methods rely on inversion schemes used to match experimental data with the theoretical data obtained from simplified models. However, due to the importance of the cross-sectional curvature of the cortical bone at low-frequency (e.g., <200 kHz), the implementation of a more elaborate model remains an open issue. Thus, the aim of this paper is to introduce a semi-analytical finite-element (SAFE) model to be used along with a genetic algorithm for the inverse characterization of cortical bone. Our proposal is to validate an inverse scheme using laboratory-controlled measurements on bone-mimicking phantoms at low frequency. An arbitrary cross-sectional geometry, instead of a plate or cylinder simplification, was implemented. Despite a computationally expensive SAFE routine, the results show that the model outputs estimated by the genetic algorithm are in good agreement with the reference values obtained by µCT images. The possibility of implementing parallel computation using graphics processing units in order to increase the level of complexity of the SAFE model may now be investigated.
Remote sparse distributed sensors to image bondline defects between a composite panel and a stiffener
Authors: Puliyakote Sreedhar , Yu Xudong , Fan Zheng , Castaings Michel
Published: November 2017

Adhesive bonding is widely used to fix skins to reinforcing elements, like stiffeners, in aerospace composite structures. A well-cured bond offers uniform stresses, good joint strength, and improved fatigue and impact resistance, and is therefore crucial to the performance of the entire structure. In the previous work by the authors, ultrasonic feature guided wave (FGW) has been discussed as a screening tool for quick inspection of the bondline between a CFRP panel and stiffener. However, it was found that material damping and weak reflections by defects along the feature makes the use of a single transducer in pulse echo mode quite inefficient. In this study, a structural health monitoring (SHM) technique is proposed to inspect the bondline, based on the radiation of plate modes into the CFRP panel when an incident FGW interacts with a defect in that bondline. A sparse array of sensors organized on the CFRP panel away from the stiffener was used to capture the waves radiating into the panel. A synthetic focusing method was applied to process the recorded signals for imaging the damaged area in the bond. Adhesive defects with varying dimensions were successfully identified in 3D FE simulations, with supporting experimental results to validate this method.
A history of noise exposure standards
Authors: Murphy William J. , Azman Amanda , Stephenson Mark R.
Published: November 2017

In the 1950s, the Committee on Hearing, Bioacoustics and Biomechanics (CHABA) investigated and developed recommendations for a variety of noise exposures. In 1956, the United States Air Force published AF Regulation 160-3, generally considered to be the first hearing conservation program in the US. The Walsh-Healy Act regulations [41 CFR 50-204.10] defined noise limits for occupational noise exposure for government supply contracts and the Federal Coal Mine Health and Safety Act of 1969 (Public Law 91-173) adopted these limits for underground and surface coal mine operations. The Occupational Safety and Health Act of 1970 (Public Law 91-596) created the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH). NIOSH published Criteria for a Recommended Standard: Occupational Exposure to Noise in 1972. OSHA promulgated a regulation for occupational noise exposure and updated that with the Hearing Conservation Amendment 29 CFR Part 1910.95. The Mine Safety Administration has regulations for noise exposure that were updated in 1999, 30 CFR part 62. The military developed the materiel acquisition standard MIL-STD 1474E for high-level impulse noise. Existing and future needs for noise exposure standards for continuous, intermittent, and impulsive noise exposures will be discussed in this paper.
Anechoic and hemi-anechoic chamber performance qualification—Review of recent standards changes
Authors: Winker Douglas
Published: November 2017

Historically, anechoic and hemi-anechoic chamber qualification has been governed by ISO 3745 Annex A. In 2017, a revised version of ISO 26101 was published. A simultaneous update to ISO 3745 Annex A, now refers to the method described in ISO 26101. Many differences exist between the previous versions of ISO 3745 Annex A and the new ISO 26101 method including curve fit, traverse direction and quantity, traverse length, measurement spatial resolution, and others. These changes will impact qualification distances and frequency ranges for anechoic and hemi-anechoic chambers. A comparison between the previous method and the new method will be presented. The impacts of those changes on existing chambers and new chamber designs will be discussed.
Recent developments in sound power level measurement standards
Authors: Hellweg Robert D.
Published: November 2017

The Acoustical Society of America ANSI accredited standards committee (S12) and the ISO committee TC43 SC1 (Noise) have developed a series of standards for measuring sound power levels of products. The engineering method to determine sound power levels in a free field over a reflecting plane is ANSI/ASA S12.54, which is the national adoption of ISO 3744. This is the standard “of choice” for a large majority of manufacturers of equipment—from consumer products to industrial machinery. In order to address issues found by using the standard over the years, some of which rarely occur, ANSI/ASA S12.54 (ISO 3744) has become larger and more complex. The ISO working group began a project to simplify ISO 3744 in order to make it simpler, easier to use, and more understandable. Instead of attempting to cover 99% of the situations that could arise during testing, the main body of the revised standard will address 90% of the cases. The issues that occur infrequently will be moved into annexes, and some parts will be consolidated into other standards. The current status of these changes to ISO 3744 and plans for the other sound power level standards will be discussed.
Measurement uncertainty and its application to standards in acoustics
Authors: Struck Christopher J.
Published: November 2017

The basic theory of measurement uncertainty as found in IEC and ISO standards is reviewed. Random error, bias error, confidence interval, coverage factor, and expanded uncertainty are defined. The concept of acceptance intervals applied to tolerance limits on the performance of electroacoustical systems for outgoing quality control and incoming inspection is presented. Calculation of the maximum permitted uncertainty is detailed and its application in the development of an uncertainty budget for a given electroacoustical measurement is shown. Example uncertainty budgets are developed for response measurements on a number of common electroacoustical devices including loudspeakers, microphones, telephones, earphones, and hearing aids. In addition to using this method to develop an uncertainty budget, it is shown how it can also be used as a diagnostic tool to find problems in the specification of various components in a measurement chain. An example of its diagnostic use on the current version of the ANSI S3.22 hearing aid standard is shown. Last, the uncertainty is calculated for a measurement of random noise and its dependence on bandwidth and averaging time is examined.
Upcoming international standards in psychoacoustics
Authors: Sottek Roland
Published: November 2017

Besides loudness, other psychoacoustic parameters like tonality and roughness can be used for product noise assessments. Tonality measurement procedures quantify the audibility of prominent tonal components and roughness evaluates modulation characteristics. In June 2017, two new ISO standards for loudness were published: ISO 532-1 (Zwicker method, based on DIN 45631/A1:2010-03) for stationary and time-varying sounds and ISO 532-2 (Moore/Glasberg method, based on ANSI S3.4-2007) for stationary sounds only. Additionally, ISO TC 43/WG 9 started now to work on ISO 532-3 for time-varying loudness based on the TVL model of Moore/Glasberg. For many years, tonality measurement procedures such as the Tone-to-Noise Ratio (TNR) and Prominence Ratio (PR) have been applied to identify prominent discrete tones. Recently, a new perceptually accurate tonality assessment method based on a hearing model of Sottek was developed which evaluates the nonlinear and time-dependent loudness of both tonal and broadband components, separating them via the autocorrelation function. This new perception-model-based procedure, suitable for identifying and ranking tonalities from any sources, is proposed for the next edition of ECMA-74 as an alternative to TNR and PR. Furthermore, it is planned to extend ECMA-74 by a roughness calculation procedure based on the same hearing model approach together with some post processing (such as a weighted modulation spectral analysis). The paper gives an overview of recent developments of psychoacoustic standards.
Acoustical nonlinearities in the structural components of the piano
Authors: Neldner Lauren , Rokni Eric , Gibson Cierra , Moore Thomas
Published: November 2017

Anomalous frequency components in piano sound, commonly referred to as phantom partials, are generally believed to originate from a geometrical nonlinearity of the string. Recent evidence suggests that phantom partials may also be produced by nonlinearities in the non-string components of the piano such as the soundboard, case, bridge, and frame. We report experimental results indicating that in addition to phantom partials, these nonlinearities associated with the piano structure also generate harmonic frequency components, which may affect the perceived sound more significantly than the phantom partials. The possible origins of this nonlinearity will be discussed.
Acoustic characterization of a Ukelin
Authors: Cottrell Tyler J. , Gleason Thomas , Faraci Philip P. , King Eoin A. , Celmer Robert
Published: November 2017

An acoustical characterization was performed on a ukelin, a wooden hybrid stringed instrument designed to combine features of the ukulele and the violin. This instrument consists of two resonant cavities at opposite ends of the instrument, one supporting sixteen strings that are individually bowed, and the other supporting 16 strings arranged in groups of four-note diatonic chords that are simultaneously plucked with the free hand, allowing an individual player to produce a melody/accompaniment combination. The ukelin design was patented in the early 20th century and sold door-to door as a novelty instrument. Modal Analysis results of a sample instrument are presented and compared with an FEA normal modes solution using ANSYS. Preliminary results show good agreement of the mode shapes for several modes between the modal results and the ANSYS predictions, but a significant difference in mode frequencies for a given mode shape. The differences in frequency are attributed primarily to unknown material properties of the wood of the sample instrument. Implications of the use of a finite-element model and of the Dynamic Modification feature of modal analysis are discussed.
Evaluating the use of crowdsourced data classification in an investigation of the steelpan drum
Authors: Garcia Joseph A. , Morrison Andrew C.
Published: November 2017

The effectiveness and reliability of crowdsourced data classification to study the acoustics of the steelpan was evaluated. A project was developed and hosted on the widely used Zooniverse website. Volunteers on the project’s site were asked to identify areas of maximum vibrations (called antinodes) and number of bright rings (fringes) in those areas for each classification. We explored various methods in ensuring volunteers generate successful classifications. The data for classification comes from a highspeed video recording, paired with Electronic Speckle Pattern Interferometry, of a strike on the steelpan's surface, which produces thousands of frames to be analyzed. We developed the project in preparation for a public release. We have analyzed the collected classifications using imported Python libraries. After validation and averaging of volunteer classifications, an Amplitude vs. Time graph was obtained for each antinode region, which included a comparison between using the area of the antinode region or the number of fringes as an indicator of a region’s amplitude.
Time-scaling vibrato tones while preserving vibrato rate
Authors: Shi Yang , Beauchamp James W.
Published: November 2017

Elongation of vibrato tones while preserving vibrato rate is a non-trivial problem in audio processing. It is well known that linear time-scaling in the time domain simply translates duration in lockstep with pitch. In the time/frequency domain, frequencies are preserved under linear time-scaling, but vibrato rates are not. Looping can preserve rate, but there is a problem synchronizing loops with vibrato cycles. Our current method is to parameterize harmonic frequency- and amplitude-vs-time variations so that vibrato rate is one of the parameters, along with vibrato depth and frequency drift. A heterodyne/filter method, where the heterodyne frequency is estimated from an FFT of the full-duration frequency deviation waveform, is used for vibrato analysis. Harmonic amplitude vibrato parameters can be estimated either by using the heterodyne/filter method directly or by using amplitude-vs-frequency relationships. Once the model is completed, the harmonic parameters can be time-scaled while keeping the vibrato rate intact. An exception to this treatment is to keep the attack and decay epochs intact. Once recomputed, the new time-varying harmonic spectrum representation is converted to a time-domain signal via sinusoidal additive synthesis.
A study on the song feelings change of soprano singers
Authors: Park Sang Bum , Bae Myungjin
Published: November 2017

The types of female vocalist are three classified into Soprano, mezzo-Soprano and Contralto according to the register. The Soprano speaks the highest voice of the female Soprano voice. In this study, we analyzed the changes in the sound width of the Coloratura Soprano, which is particularly accurate at the highest register. We measured the extent to which the world famous ten Soprano singers were attracted to the songs and presented the results to MOS SCORE. As MOS SCORE result, the more the change characteristic of the tone of the Soprano voice, the more conspicuous phenomenon becomes conspicuous. Also, the more the change in tone is displayed, the higher the extent that it is attracted by feeling the change of emotion greatly matched. By utilizing the characteristics shown in this research, the Soprano singer's prospect is inferred by referring to the Soprano singer's seamless tone change characteristics according to the correlation between tone change and fascination It became possible to do.
Time-scaling nonvibrato musical tones while preserving timbral texture
Authors: Zhao An , Beauchamp James W.
Published: November 2017

Sounds produced by linear stretching of nonvibrato single tones fail to preserve their original microvariations. While looping is commonly used for elongation with wavetable synthesis, this method requires careful attention to periodic waveform boundaries. Time extension by time reversal ensures continuity in the time domain, but this method causes audible clicks due to waveform phase reversals. This problem is overcome by using a pitch-synchronous phase vocoder method that generates time-varying harmonic amplitude and frequency envelopes. Applying the time-reversal looping method to these envelopes and converting to the time domain via sinusoidal additive synthesis can generate elongated versions of the original sound without audible clicks. To retain realism, original attack and decay time data are preserved. For shortening, envelopes are cross-faded between the attack-end and decay-begin points. As an application, the algorithm has been implemented in a score-processing music synthesis program.
Macro-scale acousto-fluidics using bulk ultrasonic standing waves
Authors: Lipkens Bart , Chitale Kedar C. , Ross-Johnsrud Benjamin P. , Presz Walter , Ilinskii Yurii A. , Zabolotskaya Evgenia A.
Published: November 2017

Macro-scale acousto-fluidics involves the interaction between acoustic radiation force exerted on a particle by bulk acoustic standing waves spanning many wavelengths, fluid drag force, and the gravitational force of the particle. Parameters are particle size, and ratio of particle to fluid density and particle to fluid compressibility. Different acousto-fluidics configurations can be used to manipulate particles in multiple ways. In cell clarification, the configuration is that of a depth flow filter with the added benefit of separating the cells out of the acoustic field, thereby eliminating any issues with filter clogging or fouling. In perfusion of stirred bioreactors, the configuration resembles that of a tangential flow filter. In a third configuration, the bulk acoustic standing wave is angled relative to the fluid velocity resulting in a label-free fractionation tool. Several underlying theoretical and numerical results of acoustic radiation force and particle trajectory calculations will be presented. A theoretical framework to calculate the acoustic radiation force on spherical, spheroidal, and cylindrical particles has been developed for any particle size relative to wavelength. An analytical solution for particle deflection angle in a planar angled standing wave and uniform flow has been developed. Experimental results will be shown to support the theory.
Acoustic Rayleigh streaming: Comprehensive analysis of source terms and their evolution with acoustic level
Authors: Daru Virginie , Baltean-Carlès Diana , Weisman Catherine , Bailliet Hélène , Reyt Ida
Published: November 2017

Rayleigh streaming is a second order mean flow generated by the interaction between a standing wave and a solid wall. At moderate acoustic levels, the streaming flow is slow, composed of two cells along a quarter wavelength: an inner cell close to the tube wall and an outer cell in the core. When increasing the acoustic level, the streaming flow inside the inner cells is marginally modified, while the outer cells are strongly distorted. The emergence of an extra cell was observed both in previous numerical simulations and experiments and it has been shown that inertia is not responsible for this behavior, which is rather due to nonlinear interactions between streaming and acoustics. In the present work these interactions are analyzed both numerically and theoretically. The averaged Navier-Stokes equations are numerically solved with acoustic correlation source terms obtained from previous full instantaneous simulations. The effect of each source term is highlighted and the source term responsible for the emergence of the extra cell is identified. The numerical results are successfully compared with the analytical solution of simplified streaming linear equations.