bluuebunny/crossref_metadata_2025 huggingface dataset:
Haptic communication and colocated performance.
Authors: Bahn Curtis , Braasch Jonas , Kouttron Dane , McDonald Kyle , Oliveros Pauline
Published: October 2013

How can experimental computer-mediated performance attain the very high levels of interpersonal intimacy and temporal intensity attained over millennia of artistic evolution involving traditional analog instruments and affordances? Current practice is lamentably missing key components of a hypothetical possibility space combining enhanced sensory perception with embodied skills inherited from traditional art forms. This presentation examines the development of the “Vibrobyte,” a small inexpensive wireless interface for the exploration of haptic communication in computer mediated and colocated performance. The Vibrobyte was developed through a research seminar at Rensselaer Polytechnic Institute and is in its first stages of artistic application. We will present the technical capabilities of the new device and examples of its first applications. Future possibilities and plans for large-scale musical compositions incorporating the Vibrobyte will be introduced.
Telematic performance in mixed realities: Virtual and acoustic spaces.
Authors: Oliveros Pauline
Published: October 2013

Performers are always dealing with latencies. Some of the smaller latencies are long forgotten and integrated into performance practice. Spaces new to performers always present challenges. Halls can be too dry giving the performer insufficient feedback to create a warm instrumental sound or in the other extreme too wet so that the clarity of the sound is blurred in the reverberations. Networked performances between two or more locations present new challenges and latencies. The mixed realities of networked performance spaces will be explored in this paper. How can performers adjust to receiving from and projecting sound into more than one space simultaneously? Where is the focus point when two or more spaces meet in a network? How can the ambiguity of simultaneous spaces provide creative inspiration for new acoustical forms?
Ultrasonic wave generation by means of highly nonlinear waves’ sensor technology.
Authors: Rizzo Piervincenzo , Khatri Devvrath , Daraio Chiara
Published: October 2013

This paper describes an innovative approach to generate and sense pulse waves in structural materials. The approach is based on the generation of highly nonlinear solitary waves (HNSWs). HNSWs are stress waves that can form and travel in highly nonlinear systems (i.e., granular, layered, fibrous, or porous materials) with a finite spatial dimension independent of the wave amplitude. Compared to conventional linear waves, the generation of HNSWs does not rely on the use of electronic equipment (such as an arbitrary function generator) and on the response of piezoelectric crystals or other transduction mechanism. HNSWs possess unique tunable properties that provide a complete control over tailoring: (1) the choice of the waves’ width (spatial size) for defects’ investigation, (2) the composition of the excited train of waves (i.e., number and separation of the waves used for testing), and (3) their amplitude and velocity. HNSWs are excited onto concrete samples and steel rebar. The characteristics of the pulses traveling along simple waveguides such as metallic plates and rods are experimentally studied.
Matching the temporal window and the fine-structure.
Authors: Hartmann William M.
Published: October 2013

Research in psychological and physiological acoustics requires careful stimulus generation. This is especially true for research in binaural hearing because of the importance of interaural phase relationships. Knowing the stimulus precisely becomes even more important when the experiment employs reproducible noise because there is less averaging over stimulus variations. The discrete Fourier transform can be used to generate noise bursts with precise timing. Although the bursts are not band limited, the amplitude and phase spectra are well characterized within any chosen band if the fine-structure is matched to the temporal window. For the example, with a 100-ms rectangular window, the components are taken to be integer multiples of a fundamental frequency of 10 Hz. With this ideal fundamental frequency, the long-term spectrum is predictable. If the window is not rectangular, the ideal fundamental frequency depends on the temporal parameters of the window. The ideal frequency can be found from the Fourier transform of the window itself. For trapezoidal and Hann (raised-cosine) symmetrical windows, the ideal frequency turns out to be the reciprocal of the total (nonsilent) duration minus the rise time (only). Windows that are not symmetrical about their center lead to phase shifts and should be avoided.
Assessment of a computational model for auditory perception for rotary-wing aircraft using human responses.
Authors: Hoglund Evelyn , Iyer Nandini , Brungart Douglas , Mobley Frank , Hall John
Published: October 2013

Traditional auditory perceptual models for detection of complex signals against complex ambient soundscapes are based on the human audibility threshold imposed upon computed representations of auditory critical band filters. Such models attempt to locate a positive signal-to-noise ratio in any critical band and then apply classic signal detection theory to derive detectability measures (d′) and probability of detection values for the event. One limitation to these models is the limited experimental validation against human sound jury performance, especially using very low-frequency target signals such as helicopters. This study compares computational auditory detection model predictions against a corresponding large sample of human sound jury data points obtained in the laboratory. Helicopter and ambient soundscape signals were obtained from high-sensitivity recordings in the field. Playback in the laboratory was achieved under high-fidelity headphones calibrated to accommodate helicopter primary rotor frequencies with minimal distortion above human sensation level. All listeners completed at least 12 000 trials detecting helicopters against rural and urban soundscapes to represent the spectrum of potential environments involved in a real world scenario. Analysis compares the human sound jury performance against a contemporary computational auditory detection model, called “AUDIB,” developed by the U.S. Army and NASA.
Simulating the precedence effect by means of autocorrelation.
Authors: Braasch Jonas
Published: October 2013

A number of algorithms have been developed to simulate the robust localization performance of humans in reverberant conditions, the most successful of which are based on (contralateral) inhibition. While these models can demonstrate the precedence effect in general, their nonlinear behavior makes it difficult to optimize their settings. A linear algorithm has now been developed to overcome this limitation. An autocorrelation algorithm determines the delay between lead and lag and their amplitude ratio for both channels. An inverse filter is then used to eliminate the lag signal before it is localized with a standard localization algorithm. Interestingly, the filter contains both inhibitory and excitatory elements, and the filter’s impulse response looks somewhat similar to the response of a chopper cell. The algorithm operates robustly on top of a model of the auditory periphery (gammatone filterbank and halfwave rectification). Due to its linear nature, the model performs better if the full waveform is reconstructed by subtracting a delayed version of the halfwave-rectified signal, with a delay time that corresponds to half the period of each frequency band’s center frequency. The model is able to simulate a number of experiments with ongoing stimuli and performs robustly with onset-truncated and interaural-level-difference based stimuli.
Passive exposure to speech stimuli facilitates within-category discrimination.
Authors: Bonnasse-Gahot Laurent , Maye Jessica
Published: October 2013

Phonetic categories are known to induce good discrimination of stimuli from different categories and poor discrimination within category [Liberman et al., J. Exp. Psych. 54, 358–368 (1957)]. In addition, passive exposure to a phonetic continuum improves discrimination if stimuli are presented according to a bimodal distribution of occurrence frequency, whereas a unimodal frequency distribution results in decreased discriminability [Maye et al., Dev. Sci. 11, 122–134 (2008)]. The present study examined whether passive exposure to bimodal versus unimodal frequency distributions results in a categorical pattern of perception. Stimuli were tokens of the syllable [ma] with rising pitch contour, where pitch slope varied across the continuum. Participants completed an AX discrimination task both before and after passive familiarization to either a unimodal or bimodal distribution of the continuum stimuli. At post-test participants in the bimodal condition showed a significant improvement in discrimination and outperformed participants in the unimodal condition. However, contrary to the predictions of categorical perception, the bimodal group’s discrimination improved most for stimuli that did not cross the category’s boundary. These data suggest that short-term changes in speech perception after passive exposure may not reflect phonetic category learning but rather enhanced encoding of frequently occurring sounds.
Music melody perception in tone-language- and nontone-language speakers.
Authors: Alexander Jennifer A. , Bradlow Ann R. , Ashley Richard D. , Wong Patrick C. M.
Published: October 2013

Speech and music both utilize pitch variation to convey contrasts in meaning: music-pitch expresses composition (e.g., the key of a piece) and effect; speech-pitch conveys pragmatic meaning and, in tone languages, lexical information. This study investigated whether experience with processing lexical pitch affects music pitch processing. 28 nonmusicians (14 native English speakers and 14 native Mandarin speakers) discriminated (experiment 1) and identified (experiment 2) short melodies. The Mandarin listeners more accurately discriminated the melodies than the English listeners (Mann-Whitney U=140.5, p<0.05; two-tailed t(21.86)=2.45, p<0.05, d=0.93), but the English listeners more accurately matched the melodies with graphical representations of the pitch movements that the mandarin listeners (Mann-Whitney U=26.5, p<0.005; two-tailed t(25.44)=−3.94, p<0.001, d=1.15). This indicates that experience with lexical-pitch processing may enhance attention to pitch and thereby facilitate pitch-pattern discrimination. However, learned linguistic pitch-pattern categories may interfere with novel, nonlinguistic, pitch-patterns, thereby impairing identification of musical pitch-patterns. Our study contributes to a literature suggesting that processing of music-pitch and speech-pitch utilizes shared cognitive mechanisms (e.g., Alexander et al., Interspeech 2005). Results are discussed with regard to a cognitive-processing framework that involves the influence of experientially acquired top-down pitch category information upon novel bottom-up pitch input during certain tasks. [Work supported by NU Cognitive Science Graduate Fellowship to J.A. and NIH Grants DC005794 (to A.B.) and HD051827 DC007468 (to P.W.)]
Similarities in the acoustic expression of emotions in English, German, Hindi, and Arabic.
Authors: Pell Marc , Paulmann Silke , Dara Chinar , Alasseri Areej , Kotz Sonja
Published: October 2013

Based on the hypothesis that emotion expression is in large part biologically determined (“universal”), this study examined whether spoken utterances conveying seven emotions (anger, disgust, fear, sadness, happiness, surprise, and neutral) demonstrate similar acoustic patterns in four distinct languages (English, German, Hindi, and Arabic). Emotional pseudoutterances (the dirms are in the cindabal) were recorded by four native speakers of each language using an elicitation paradigm. Across languages, approximately 2500 utterances, which were perceptually identified as communicating the intended target emotion, were analyzed for three acoustic parameters: f0Mean, f0Range, and speaking rate. Combined variance in the three acoustic measures contributed significantly to differences among the seven emotions in each language, although f0Mean played the largest role for each language. Disgust, sadness, and neutral were always produced with a low f0Mean, whereas surprise (and usually fear and anger) exhibited an elevated f0Mean. Surprise displayed an extremely wide f0Range and disgust exhibited a much slower speaking rate than the other emotions in each language. Overall, the acoustic measures demonstrated many similarities among languages consistent with the notion of universal patterns of vocal emotion expression, although certain emotions were poorly predicted by the three acoustic measures and probably rely on additional acoustic parameters for perceptual recognition.
Effects of acoustic cue manipulations on emotional prosody recognition.
Authors: Dara Chinar , Pell Marc
Published: October 2013

Studies on emotion recognition from prosody have largely focused on the role and effectiveness of isolated acoustic parameters and less is known about how information from these cues is perceived and combined to infer emotional meaning. To better understand how acoustic cues influence recognition of discrete emotions from voice, this study investigated how listeners perceptually combine information from two critical acoustic cues, pitch and speech rate, to identify emotions. For all the utterances, pitch and speech rate measures of the whole utterance were independently manipulated by factors of 1.25 (+25%) and 0.75 (−25%). To examine the influence of one cue with reference to the other cue the three manipulations of pitch (+25%, 0%, and −25%) were crossed with the three manipulations of speech rate (+25%, 0%, and −25%). Pseudoutterances spoken in five emotional tones (happy, sad, angry, fear, and disgust) and neutral that have undergone acoustic cue manipulations were presented to 15 male and 15 female participants for an emotion identification task. Results indicated that both pitch and speech rate are important acoustic parameters to identify emotions and more critically, it is the relative weight of each cue which seems to contribute significantly for categorizing happy, sad, fear, and neutral.
Hemispheric processing of pitch accent in Japanese by native and non-native listeners.
Authors: Tu Jung-Yueh , Wu Xianghua , Wang Yue
Published: October 2013

It is well established that language processing is left hemisphere dominant. Previous findings, however, indicate that lateralization of different levels of linguistic prosody varies with their functional load as well as listeners' linguistic experience. This study explored the hemispheric processing of Japanese pitch accent by native and non-native listeners differing in experience with pitch, including 16 native Japanese participants, 16 Mandarin Chinese participants whose native language has linguistic tonal contrasts, and 16 English participants with no tone or pitch accent background. Pitch accent pairs were dichotically presented and the listeners were asked to identify which pitch accent pattern they heard in each ear. Preliminary results showed that for all the three groups, the percentage of errors for the left ear and that for the right ear were comparable, indicating no hemispheric dominance. The Japanese group did not reveal left hemisphere dominance, as previously found for linguistic tone processing by native listeners. The performance of Mandarin group infers that tone language background did not significantly affect the lateralization of pitch accent. These findings are discussed in terms of how linguistic function differentially influences the hemispheric specialization of different domains of prosodic processing by native and non-native listeners. [Work supported by the NSERC.]
The effect of weak tone on the f0 peak alignment.
Authors: Chang Seung-Eun
Published: October 2013

The f0 peak sometimes occurs after the syllable with which it is associated, and the peak alignment varies, depending on several factors such as lexical tone target, neighboring tones, focus, and so forth. This study investigates the effect of weak tones on the alignment of f0 peaks with three tone types (i.e., H, M, and R) of South Kyungsang Korean, spoken in the southeastern part of Korea. When three tone types are followed by one or two unstressed suffixes, R was found to have the maximum amount of peak delay and M was found to have the minimum amount, i.e., the peak came in the second syllable, following the R-toned syllable, but the peak came in the syllable following the H-toned syllable. This peak delay was not found for M. Thus, it is argued that the tone alternation patterns in suffixed words are not random; rather, they systematically reflect the phonetic implementation of each tonal target. For example, the peak is in the final portion of a syllable in R, and it takes more time for the peak to be fully realized. This effect can be clearly observed when the following tone is weak.
Geoacoustic inversion over a basalt seafloor.
Authors: Heaney Kevin D. , Vera Michael
Published: October 2013

Geoacoustic inversion from data just off a volcanic island (Kauai) poses significant challenges. One of the significant challenges is to separate the effects of seafloor roughness and shear wave conversion in the basement. Lava flow fields are known to have significant roughness on several scales relevant to low-frequency acoustic propagation (75 Hz). Basalt is known to have a very high-compressional speed of 3000 m/s and a variable shear speed ranging from 500 to 2000 m/s. The combination of shear and roughness can lead to significant ambiguity while performing a geoacoustic inversion because both mechanisms can lead to attenuation of the coherent field. During the BASSEX 2004 experiment up to 20 transmissions from the fixed NPAL source (75 Hz, m-seq with a 50-Hz bandwidth) were received on a towed horizontal line array at many orientations and ranges from the source. In this paper we look at several short-range transmissions and attempt to sort out the scattering effects of roughness with the attenuation effects of shear wave conversion in the sediment. The two mechanisms will be sorted out using simultaneous narrowband (transmission loss) and broadband inversions.
Inverting for the properties of an elastic seafloor using complex-density equivalent fluids.
Authors: Vera Michael , Heaney Kevin
Published: October 2013

Receptions were recorded from a bottom-mounted broadband source (with a center frequency of 75 Hz) located near Kauai as part of the basin acoustic seamount scattering experiment (BASSEX). Travel times for arrivals from this source have been modeled at basin-scale ranges using complex-density equivalent fluids for the elastic seafloor material. The collection of acoustic data at shorter ranges as part of BASSEX allows for a more detailed examination of the accuracy attainable by an equivalent-fluid representation of the seafloor. The use of equivalent fluids is intended to depict the conversion of acoustic energy into shear waves. The performance and stability of propagation models can be substantially improved if equivalent fluids can be used to accurately characterize bottom interaction. Simulations have been performed in order to search for the equivalent fluid that best explains received data at a range of a few kilometers. The reflection coefficient of this equivalent fluid can then be matched to parameters of an elastic solid (density, sound speed, and shear speed) for the relevant grazing angles. The ability of these models to reproduce features of the data will serve to indicate the importance of elastic effects in the experimental results. [Work supported by ONR.]
Acoustical modeling of Russell Johnson’s Singapore projects.
Authors: Siebein Gary , Lilkendey Robert , Bettcher Adam , Robinson Threcia , Fisher Joshua
Published: October 2013

The University of Florida Acoustics Lab had the pleasure of working with Russell Johnson and others at Artec in acoustical modeling of several halls, most notably, the Singapore concert and opera rooms. It was truly a pleasure to meet with the talented multidisciplinary staff that Russell put together at Artec to address the development of what can arguably be called the Concert Hall of the 21st Century: a traditional concert room that is amazingly adaptable through reverberation chambers, moving canopies, and adjustable absorption to a wide range of venues and a wide range of architectural styles. The inherently architectural and aesthetic basis Russell used to develop his style inspired a generation of architectural and acoustics students who worked on these projects with us.
A video retrospective of the life of Russell Johnson.
Authors: Nakajima Tateo
Published: October 2013

A video collection of slides set to music from the life of Russell Johnson will be shown. Included are photos from early childhood provided by Johnson's sister, Barbara Mansfield. These depict background and early childhood in Pennsylvania and Johnson's military service during World War II. Later photos from Artec's archives show Johnson with colleagues, friends, and artists throughout his long career in acoustics.
Estimation of the temporal structure of the echo from the fish by using the broadband sonar signal of the dolphin.
Authors: Matsuo Ikuo , Imaizumi Tomohito , Akamatsu Tomonari , Furusawa Masahiko , Nishimori Yasushi , Ogawa Shinji
Published: October 2013

Dolphins can identify prey by using the broadband sonar signals. Behavioral experiments indicate that dolphins can detect and discriminate targets in highly cluttered and noisy environments (Au, (1993)]. The sonar system can be improved by clarifying the ability of the dolphin and this improved sonar system is useful for fish species identification. The echo from the fish contains components resulting from multiple reflections, for example, the swim-bladder and body surface of the fish. Therefore, it is necessary to determine the distance and intensity, corresponding to the reflectivity, of these reflectors. We analyzed the echoes from fishes in seas close to Japan by using the Hilbert transform. First, we analyzed echoes which were measured from three species of the anaesthetized fish in a water tank. It was clarified that both the numbers and intensity of reflectors and the duration of the echo were varied dependent on the species, the individual, and the tilt angle. Second, we analyzed the echo which was measured from the fish suspended by nylon monofilament line in the open sea. It was clarified that the numbers and intensity of reflectors were varied dependent on the species and movement of the fish.
The dynamics of the bottlenose dolphin sonar beam.
Authors: Starkhammar Josefin , Kuczaj Stan A. , Amundin Mats , Nilsson Johan , Almqvist Monica , Persson Hans W.
Published: October 2013

Much research on dolphin echolocation has focused on animals that have been trained to remain stationary or to carry a device that allows the animals to move but restricts the location of the sonar beam. In such cases, a small number of hydrophones measures sonar characteristics while dolphins solve echolocation tasks. As a result, much is known about the beam axis but relatively little is known about other parts of the beam. One reason for this disparity is that it has been difficult to interpret the results from off axis measurements using a small number of hydrophones (that may or may not sample simultaneously). In this paper, we report results from a system of 47 hydrophones in a 0.75 × 0.75 m2 matrix that allowed measurements to be made at multiple locations in the beam simultaneously, with a sample rate of 1 Msample/s. The system both visualizes and records echolocation clicks in real time across the whole cross section of the beam, hence allowing the full dynamics of the sonar beam to be revealed. As a demonstration of the system's utility, we present results obtained with the system to assess the acoustic properties of clicks produced spontaneously by free-swimming dolphins.
Automated detection and localization of nonstereotyped bowhead whale calls in the presence of seismic airgun signals, incorporating multiple directional autonomous recording packages (DASARs).
Authors: Thode Aaron , Mathias Delphine , Blackwell Susanna B. , Kim Katherine H. , Greene Charles R.
Published: October 2013

In 2007 and 2008, 35 directional autonomous recording packages (DASARs) [Greene et al., J. Acoust. Soc. Am. 116, 799–813 (2004)] were deployed at five sites over a 280 km swath in the Beaufort Sea to monitor the annual migration of the bowhead whale (Balaena mysticetus) population during seismic exploration activities. To expedite analysis, automated detection and localization methods are applied to each DASAR data set, employing a four-stage detection and classification algorithm. The first three stages consist of the detection phase, while the final classification stage uses image thresholding, morphological processing, edge detection, and image segmentation to extract key features of signals from equalized spectrograms. These features are then compared to results from other DASARS at a given site in order to identify a single call across all DASARs. Bearings from each DASAR are then crossed to provide a location. Manually reviewed data sets are used to optimize the algorithm parameters for a given site and a given set of environmental conditions. The total detection and classification performance of the combined DASAR set will be compared with the performance of a single DASAR. [Work supported by Shell Exploration and Production Company.]
Killer whales at the Pribilof Islands: Who are they and what are they doing.
Authors: Newman Kelly , Springer Alan , Matkin Craig
Published: October 2013

The Pribilof Islands, located in the eastern Bering Sea, are the site of the largest concentration of northern fur seals in the world. Despite the occurrence of transient killer whales on a near daily basis during the fur seal breeding season, these whales are unknown in terms of their social structure and overall range. Orcas were recorded with autonomous acoustic recorders at the Pribilof Islands in the summers of 2006 and 2008. This is the first study of call types and whistles of these killer whales. Whistles have been described for other odontocete species but not yet for transient killer whales. This study also reports on temporal and spatial dynamics of killer whale occurrence at the two major Pribilof Islands, St. Paul and St. George Islands. Call matches between the years and locations were analyzed to ascertain visitation patterns, predation sounds, and diurnal activity near the fur seal rookeries. Whale vocalizations from the Pribilofs were compared to other regions in Alaska. Thus far, there is no match between the calls of the Pribilof whales and those in regions of Southeast Alaska and Prince William Sound, but some calls bear a structural resemblance to calls produced by whales recorded near False Pass, AK.
Localization of killer whale mother, juvenile, and calf vocalizations.
Authors: Grebner Dawn M. , Bradley David L. , Capone Dean E. , Parks Susan E. , Miksis-Olds Jennifer L. , Ford John K. B.
Published: October 2013

A dataset of killer whale female (mother), juvenile, and calf vocalizations was collected with a hydrophone array in Johnstone Strait in the summers of 2006 and 2007. The vocalizations were spatially and temporally localized together with behavioral observations. The analysis is focused on pulsed call production variation when a mother is with her juvenile(s) and/or calf and when she is separated from one or more of them. Analysis is centered on the frequency-time structure of the vocalizations. This circumstance provides a unique opportunity to gain insight into the communication between individuals within a common social subset of a matriline or pod. This subset is characteristically tighter in association than many other intramatrilineal groups and can offer a glimpse into early vocal exchange and development.
Environmental effects on short-range acoustic propagation and sensor performance.
Authors: Albert Donald G.
Published: October 2013

Autonomous passive acoustic sensor systems can potentially detect, identify, and locate sound emissions from gunfire, explosions, vehicles, and animals. However, since sound propagation through the atmosphere is influenced by many environmental conditions including meteorology, ground impedance, and barriers or obstacles, these effects need to be understood and included in sensor system design to achieve accurate performance. Low-frequency short-range measurements using impulsive sources will be presented to quantify these effects on acoustic wave form shape and amplitude attenuation. In urban areas, multiple reflections and diffractions can add enough complexity to explosion wave forms that it becomes difficult for a human listener to identify them as explosions. In these areas, classical methods to determine source locations such as beam-forming or direction-of-arrival bearing estimates from time delays can fail completely. Novel signal processing methods that incorporate the complexity of propagation in these environments can produce accurate localizations. [Work funded by U.S. Army.]
Orthogonal acoustic sensor package for human detection in quiet and noisy environments.
Authors: Sabatier James M. , Ekimov Alexander E.
Published: October 2013

Seismic and low-frequency acoustic sensors are severely limited by background vibrations and sound in noisy (urban) areas and a human's ability to mask the impulsive signal from his or her footsteps. Typically, noise levels are highest at low frequencies and roll off at higher frequencies. Recent research has shown that the ultrasonic signals from footsteps can be passively detected in urban areas and in buildings and are relatively independent of attempts at masking. Coupling this sensor with ultrasonic Doppler sonar and processing algorithms that tie footsteps to corresponding human motion yields an orthogonal sensor package with high probability of detection and minimal false alarms. Coupling the ultrasonic sensor package with the low-frequency traditional sensors (such as seismic sensors) forms the universal acoustic sensor package that potentially increases the probability of human detection in high-noise urban and low-noise rural environments. Successful signal processing algorithms for the sensor package are developed and tested. [Work supported by the Department of the Army, Army Research Office, Contract No. W911NF-04-1-0190.]
Impulsive sound source localization using distributed elevated acoustic sensors.
Authors: Di Xiao , Wagstaff Ronald , Anderson John , Gilbert Kenneth
Published: October 2013

For detecting and localizing impulsive sources in the daytime, distributed elevated acoustic sensors with large base line separations have distinct advantages over small ground-based arrays. First, during the day, the signal levels are generally higher at altitude than on the ground. Second, the large base lines provide improved localization accuracy. Results are reported from a distributed array of acoustic sensors deployed during an experiment in Bourges, France during June of 2008. The distributed array consisted of microphones and global positioning system (GPS) receivers attached to the tether lines of several widely separated balloons. The sound sources were various impulsive devices. Data from the experiment are presented and discussed. In particular, the localization error is analyzed as a function of the GPS accuracy and the motion of the balloons. Possible ways to improve the localization accuracy are suggested. [Research supported by the U. S. Army TACOM-ARDEC at Picatinny Arsenal, NJ.]
Modes of the kalimba resonator box.
Authors: Ludwigsen Daniel
Published: October 2013

The kalimba is an African instrument with plucked metal tines mounted on a resonator box made of hardwood. The box features both acoustic (related to air in the cavity and holes) and structural resonances. An experimental modal analysis of the box indicates some agreement between the frequencies of these structural resonances and quickly decaying spectral components of the attack. Furthermore, direct measurements of mechanical impedance at the bridge show support for the effective radiation of sound at the fundamental frequencies of the tines. A finite element model of the resonator box corroborates these results, which show several ways the design of the box affects a musical and distinctive instrument.
Measurement and modeling of the open end correction for driven pipes.
Authors: Ludwigsen Daniel , Hunt Linda
Published: October 2013

The end correction that accounts for the inertial impedance at the open end of a pipe is a widely used refinement to lumped-element models, and many variations have been investigated. This study measures the end correction for 1 m closed-open pipes of varying diameters, exposed to a single-frequency external sound field created by a subwoofer in an anechoic facility. The frequency response of each pipe was measured as the ratio of the pressure at the closed end of the pipe to a reference pressure at the open end. Using an expression for the predicted mode frequencies based on the assumption that the driving pressure is uniform across the open end, the driven end correction was derived from the measured frequency response. The interaction of the pipe and the external sound field can be visualized in a finite element model, with alternative estimates of the driven end correction. Preliminary results indicate that the driven end correction can be as large as the diameter, more than three times the expected value for a passive open end.
Parameter estimation and inversion for wind instrument physical models.
Authors: Sterling Mark , Dong Xiaoxiao , Bocko Mark
Published: October 2013

An outstanding goal in the field of musical instrument physical modeling has been the definition of a robust parametric and expressive representation or coding for musical audio. For this purpose, accurate dynamical models of musical instrument systems must be supported by algorithms that can provide suitable sets of control parameters for producing some desired output. We describe an estimation algorithm for clarinet physical modeling. However, the results could be applied to a broader class of convolutional wind instrument models, which fit the McIntyre–Schumacher–Woodhouse framework. Three fundamental signals in clarinet physical modeling are the blowing pressure pm, bore pressure pb, and flow u inside the mouthpiece. These are related via the nonlinear reed-valve characteristic and the air column impulse response. Assuming pb is given or approximated from a digital recording using known radiation characteristics, pm and u are iteratively estimated against one another, fitting the model to pb. This is accomplished with an informed inversion of the reed valve and an adaptive (LMS) inverse of the bore impulse response. This method supplants prior work we have done where blowing pressure waveforms were computed by envelope detection. Results are verified with numerous audio examples. [Work partially supported by NSF Grant IIS-555457.]
Experimental modal study of the Kurdish long necked lute, Tanbour.
Authors: Alghassi Hedayat , Ferdowsi Sohrab , Alghassi Roozbeh , Khademi Babak
Published: October 2013

This research presents the results of an experimental study of the vibration properties of the Kurdish long necked lute called Tanbour (aka Tambour, Tanbur, or Tamurah). A system transfer function of this musical instrument has been derived. [Hedayat Alghassi et al., “Time series analysis of the Kurdish long necked lute Tanbour,”, J. Acoust. Soc. Am. 122 (2007)]. To investigate the complex vibrational dynamics of Tanbour, the deflection patterns of Tanbour’s pear shaped soundboard was acquired using a low-end time-averaged electronic speckle pattern interferometery (ESPI) imaging system. Later, the acquired image patterns were categorized as three resonance modes: near certain, dipolar, and quadrupolar. The three noticeable modes are assigned to the specific plectrum angles and positions. Moreover the short term Fourier transform (STFT) of the sound produced is derived for those plectrums. The strings were excited by a controlled mechanical plucker to maintain a high precision. Finally the sound spectra were related to the vibrational modes of the instrument, so one can approximately speculate the vibrational mode of Tanbour’s soundboard from the STFT spectra for a basic plectrum.The criteria of observing three obvious vibration modes from the ESPI acquired images can also be used to achieve the optimum location of the bridge on the sound board.
Fire resistance and noise control in multifamily buildings.
Authors: Quirt J. D. , Nightingale T. R. T.
Published: October 2013

The walls and floors that separate dwellings in apartment buildings and condominiums must serve many functions other than structural support. To select wall or floor assemblies, designers need ready access to collections of test ratings, so this talk begins with a brief overview of some key factors affecting both the fire resistance and sound transmission ratings of wall assemblies and floor/ceiling assemblies with gypsum board surfaces. For successful buildings, however, designers must also appreciate how the overall fire resistance and sound isolation may be compromised by details at junctions and penetrations, and use a system approach that respects the requirements for both sound and fire controls. This presentation will focus on fire stops and fire blocks in the context of Canadian codes and standards, illustrate design options for fire stops at some common junctions and penetrations (mainly in the context of lightweight framed constructions), and provide guidance on corresponding acoustical issues.
Impact of material flammability regulations on acoustical treatment selection for heavy-duty vehicles.
Authors: Moritz Charles , Bush Kendall , Shaw Jennifer
Published: October 2013

Typical acoustical materials used in cars and trucks include polyurethane foam, polyester fiber blends, vinyl barriers, and various plastic or fabric facings. These materials are required to pass Federal Motor Vehicle Safety Standard 302, which regulates the speed at which a horizontal sample of the material can burn. Buses and specialty vehicles can be subject to more stringent flammability or smoke development requirements. These additional requirements may preclude the use of some common acoustical materials or require the addition of fire retardant chemicals or special facings. This paper reviews the commonly specified flammability regulations used with industrial vehicle acoustical materials and discusses their impact on material selection, performance, and cost.
Green's function model for time-reversal focusing of elastic surface waves.
Authors: Zabolotskaya Evgenia A. , Ilinskii Yurii A. , Hamilton Mark F.
Published: October 2013

Time-reversal focusing applied to an object buried in soil improves the ability to focus energy on the object, suggesting a promising method for mine and IED detection. As a rule, these devices are buried close to the ground surface at a depth smaller than an elastic surface wave penetration depth. A Green’s function approach is used to evaluate the field scattered by the object. Both the Green’s function and the source function representing the scattering site are expanded in eigenfunctions of the homogeneous wave equation. When the object is acoustically compact, the scattered wave amplitude on the surface is described in the frequency domain by a Hankel function of order zero. Below the surface, the scattered wave amplitude is described by a Bessel function of order zero multiplied by exponentials that decay with depth, plus its Hilbert transform. The Green’s function in the time domain is zero for negative time, and for positive time it is the Fourier transform of the Bessel function of order zero multiplied by the exponential depth dependence. The Green’s function is used twice to calculate scattering from the object, first by the probe wave and next by the time-reversed wave. [Work supported by ONR.]
Broadband duct noise attenuation by a middle-ear mechanism.
Authors: Huang Lixi
Published: October 2013

Low-frequency duct noise is difficult to control passively by any device limited by its total volume due to system stiffness. When a side-branch device is used, cavity air becomes incompressible toward the dc frequency. One way to tackle the relative incompressibility for low to medium frequencies is to introduce acoustic phase difference in the cavity air oscillation, which otherwise behaves like the low-order room acoustics modes. The introduction of a light plate covering the cavity in our previous studies [J. Acoust. Soc. Am. 119, 2628–2638 (2006)] does essentially that by enhancing the non-volume-displacing modes. Optimization shows that the required stiffness-to-mass ratio is much beyond what is available for existing bulk materials. In the present study, an alternative device that resembles the ossicular structure of the mammalian middle ear is introduced. The acoustic signal is passed along through a rigid pin which simulates the ossicular bones via its longitudinal motion. Contrasting with the usual flexural waves in plate or membrane structures, the bone transmission has almost infinite speed and it creates the phase difference needed to overcome the system stiffness. Theoretical predictions show that the performance of such device is comparable and better than the idealistic plate silencer with interesting comparisons of features.
Comparison of surface velocity measurement using a scanning laser vibrometer and acoustic holography.
Authors: Pingle Pawan , Bruderer Scot , Niezrecki Christopher , Avitabile Peter
Published: October 2013

A significant amount of interest exists in performing noncontacting full-field surface velocity measurement. For many years traditional surface velocity measurements have been made by using a scanning Doppler laser vibrometer (SDLV). Nearfield acoustical holography is another approach that enables reconstruction of quantities such as the acoustic pressure, surface velocity, intensity, and power radiated from a structure into three-dimensional space, based on the sound pressure measured at a two-dimensional surface. Within this work the surface velocity of a clothes dryer panel is computed based on the acoustic field pressure measurements by using the Helmholtz equation least square (HELS) method, in which the reconstructed sound field is optimized by using spherical wave functions. The dryer panel is measured using an SDLV as well as a 64-channel microphone array. The reconstructed full-field surface velocity using the HELS method is compared to the measurement from the laser vibrometer during operation and also at discrete resonant frequencies.
Small vocal-tract cavities revealed by magnetic resonance imaging and their acoustic influences.
Authors: Honda Kiyoshi , Takemoto Hironori , Kitamura Tatsuya
Published: October 2013

In natural speaking conditions, the vocal tract exhibits small cavities in the hypopharyx and oral cavity, while their acoustic effects have not been fully recognized. Acoustic studies based on static and dynamic magnetic resonance imaging of the vocal tract in three dimensional have shown that these cavities cause regional resonance and antiresonance in the vocal tract. The hypopharyngeal cavities, including the supraglottal laryngeal cavity and bilateral cavities of the piriform fossa, characterize vowel spectra in the higher frequencies and contribute to determining voice quality and speaker characteristics. The laryngeal cavity functions as a Helmholtz resonator to generate an extra formant in the vicinity of 3 kHz, and the piriform fossa forms a pair of side-branches of the vocal tract to cause spectral zeros in the vicinity of 4–5 kHz. The bilateral interdental spaces form a pair of side-branches in the oral cavity in nonlow vowels, and their geometry varies with articulation. Their antiresonance frequency is below 2 kHz in /i/, while it rises toward /a/ crossing the second formant in transition, and thus causing a small discontinuity of that formant between the two vowels.
Subglottal coupling as a quantal basis for the feature [back].
Authors: Sonderegger Morgan , Chi Xuemin
Published: October 2013

A model of acoustic coupling between the oral and subglottal cavities is described, which predicts attenuation of vowel formant prominences and discontinuities in formant trajectories near resonances of the subglottal system. The hypothesis that these effects on F2 near the second subglottal resonance (SubF2) are quantal effects for the feature [back] is examined using acoustic and subglottal data from English-speaking adults. Experimental studies of F2 and SubF2 in English vowel production [Chi and Sonderegger, JASA 122, 1735–1745 (2007)] are reviewed and show that attenuation of second formant prominence and discontinuities in F2 trajectories near SubF2 consistently occur in back-front diphthongs, in accordance with the acoustic model, while for monophthongs front and back vowel F2 values pattern above and below SubF2, as expected under the quantal hypothesis. An additional analysis of the data is presented, showing that breathiness, attenuation, and discontinuity are positively correlated across back-front diphthongs, as predicted by the acoustic model. Lastly, a cross-linguistic survey of F2 data from 45 languages from the literature is presented, showing the cross-linguistic plausibility of the hypothesis that [+back] and [−back] vowel F2 values are separated by SubF2.
Quantal relations from the acoustic coupled resonators of sonorant consonants.
Authors: Espy-Wilson Carol
Published: October 2013

In this talk, we discuss the quantal relations that result from the coupled resonators of sonorant consonants. We have developed three dimensional geometries for light and dark /l/’s and for retroflex and bunched /r/’s based on MRI data from several speakers. In addition, we have used a computer vocal tract program (VTAR) to develop simpler models from MRI-derived area functions for /r/’s, nasal consonants, and nasalized vowels. Our vocal tract modeling shows that zeros occur in all of these cases due to side branches. For /l/, the side branches are the result of the palatal constriction with airflow around the sides of the tongue. For /r/, the side branches are due to the large front cavity, sometimes with space under the tongue. For the nasals and nasalized vowels, zeros occur due to the coupling between the oral and nasal cavities and the paranasal sinuses. We will discuss how the frequencies of the zeros vary as a result of changes in articulatory configurations. In addition, for /r/, we will show the quantal relationship in the frequency of F3 and the relative lengths of the cavities anterior and posterior to the palatal constriction.
Acoustic characteristics of glides /j/ and /w/: Interactions with phonation frequency.
Authors: Hunt Elisabeth
Published: October 2013

As part of a larger study of acoustic characteristics of glides, patterns in the movements of the fundamental frequency of phonation (F0) were measured during utterances of the glide segments /j/ and /w/. Two male and two female American English speakers produced intervocalic glides in six different vowel contexts and five different prosodic contexts. F0 contours show pronounced valleys during glide segments, in which the frequency of phonation is decreased relative to the surrounding prosodic contour. These valleys occur more frequently for higher fundamental frequencies, as in female speech. Effects of surrounding vowel and prosodic contexts were also observed, with F0 valleys more often occurring during glides when the following vowel is pitch accented or when the height of the surrounding vowels is high. The results are interpreted in terms of acoustic loading on the glottal source; the effects of which are most pronounced when a narrow vocal tract constriction (as in a glide segment) lowers the first formant frequency into the range of F0. This interaction with F0 may provide an enhancing acoustic cue to the presence of glides in the speech stream, particularly for female speakers or high-vowel contexts. [Work supported in part by NIH Grant No. DC00075.]