bluuebunny/crossref_metadata_2025 huggingface dataset:
Using channel-specific models to detect and remove reverberation in cochlear implants
Authors: Desmond Jill M. , Throckmorton Chandra S. , Collins Leslie M.
Published: September 2012

Reverberation results in the smearing of both harmonic and temporal elements of speech through self-masking (masking within an individual phoneme) and overlap-masking (masking of one phoneme by a preceding phoneme). Self-masking is responsible for flattening formant transitions, while overlap-masking results in the masking of low-energy consonants by higher-energy vowels. Reverberation effects, especially the flattening of formant transitions, are especially detrimental to cochlear implant listeners because they already have access to only limited spectral and temporal information (Kokkinakis and Loizou, 2011). Efforts to model and correct for reverberation in acoustic listening scenarios can be quite complex, requiring estimation of the room transfer function and localization of the source and receiver. However, due to the limited resolution associated with cochlear implant stimulation, simpler processing for reverberation detection and mitigation may be possible. This study models speech stimuli in a cochlear implant on a per-channel basis both in quiet and in reverberation, where reverberation is characterized by different reverberation times, room dimensions, and source locations. The efficacy of these models for detecting the presence of reverberation and subsequently removing its effects from speech stimuli is assessed. [This work was funded by the National Institutes of Health (NIDCD), R01-DC-007994-04.]
Optimal categorization of sounds varying on a single dimension
Authors: Kittleson Megan , Diehl Randy L. , Lotto Andrew J.
Published: September 2012

Listeners were randomly presented narrow-band filtered noise bursts that varied in filter center frequency from two overlapping, Gaussian-like distributions. Participants mapped these distributions of sounds onto creatures in a video game where they received visual and auditory feedback about their accuracy. Categorization boundaries for each participant were estimated using logistic regression and compared with the optimal boundary from an ideal observer model. The participants appeared to be able to establish near optimal boundaries rapidly and had a remarkable ability to shift these boundaries when the underlying distributions changed - even when these changes were not explicitly signaled. These results suggest that listeners maintain a rather detailed representation of distributional information that is continuously updated during the task. This interpretation is in line with the assumptions underlying many current models of perceptual (statistical) learning in speech perception. However, it is possible to get optimal-like behavior by maintaining a general distributional representation or by using simpler “local” strategies based on only a few of the most recently experienced exemplars. The results will be presented with multiple categorization models, which testify to the difficulty of interpreting claims of distributional learning in categorization. [Work supported by NIH-NIDCD.]
Ictal and interictal changes in auditory processing
Authors: Daly David M.
Published: September 2012

Altered neuronal functioning manifest in seizures can also cause inter-ictal misperceptions. The present case experienced nausea, head-turning, and automatism with loss of consciousness; following this, he could see and hear, but could not speak for up to 30 min. Left hemisphere initiated speech; seizures involved right frontal and anterior temporal areas. He underwent anterior temporal lobe resection, and for the next year, seizures were medically controlled. Then seizures recurred; although he remained conscious, he was often amnestic instead, and, again, post-ictally mute. He underwent resection of right frontal lobe; he recovered over the next year with only prophylactic medication. Patient was tested using pre-recorded sets of GY, BDG, and iIe delivered through headphones [J Neurophysiol. 44:1, 200-22 (1980)]. In the year after first surgery, he classified vowels appropriately, but GY as `not /ye/' and /ye/, and BDG as /be/ and /de/; right ear and binaural performances were statistically less anomalous than left ear. Following second surgery, he classified GY and BDG appropriately. Left ear performance varied by at most chance from standard; right ear was indistinguishable from the standard (p < 0.0001).
Discreteness and asymmetry in phonological representations of words
Authors: Lahiri Aditi
Published: September 2012

Lexical phonological contrasts are generally binary and abound in asymmetries. For example, vowels can contrast in nasality (oral vs. nasal), but the presence of contrastive nasal vowels implies the presence of oral vowels, and not vice versa. The occurrence of geminates in a language implies the presence of single consonants and therefore, a contrast in consonantal length. Here we address the question of how these asymmetries constrain phonological representations of WORDS in the mental lexicon, and how these constraints affect language processing and change. Various phonological contrasts will be discussed including features, length, and tone, claiming that representations are discrete and asymmetric which in turn lead to asymmetry in processing. Experimental evidence will be presented from behavioural as well as brain imaging studies in Bengali, English, and German.
Processing pronunciation variants: Rules and representations
Authors: Connine Cynthia M. , Sajin Stanislav
Published: September 2012

Both representational and inference rule mechanisms have been proposed for recognizing pronunciation variants. In our work, we have advanced a view for recognizing pronunciation variants in which multiple forms are represented in the lexicon, with non-canonical forms represented based on their frequency of occurrence and canonical forms represented in a privileged (immune to frequency of occurrence) status due to their congruence with orthography. These investigations have focused on variants in which the relevant alternation was word internal (e.g. schwa vowel deletion, flapping and nasal flaps). Other classes of pronunciation variants are formed due to interactions with segmental properties of surrounding words (e.g. place assimilation, fricative assimilation); the processing explanation advanced for such variants has focused on phonological inference rules that recover underlying representations. The current project investigated the relative role of inferential processes and representation in processing variants formed due to interaction at word boundaries (e.g. fricative assimilation).
Passive sonar target tracking with a vertical hydrophone array in a deep ocean environment
Authors: Danesh Sheida , Schmidt Henrik
Published: September 2012

When operating in a deep ocean environment, limited power availability makes it imperative to conserve energy. This is achieved through the use of computational efficiency, as well as a passive sonar configuration that eliminates the need for a sonar source. Mallat and Zhang’s Matching Pursuits algorithm with a Kalman filter is implemented for use in passive target tracking. This makes it possible to determine the range of a moving target through the use of dot products and other simple calculations. The model setup used to test this approach includes a vertical hydrophone array at a depth of 4-5km and a near surface target between 10 and 45 km away. Simulated results using ray tracing (BELLHOP) and wavenumber integration (OASES) were used in developing this method. Preliminary results indicate this to be an effective means of target tracking. Possible future improvements include determining the bearing as well as the range of the target.
Application of a model-based depth discriminator to data from the REP11 experiment
Authors: Bissinger Brett E. , Culver R. Lee
Published: September 2012

We address application of a passive, model-based depth discriminator to data from the REP11 experiment. The method is based on a mode subspace approach (Premus, 2007) which uses environmental information along with a normal mode based acoustic simulation to predict the propagating mode structure. This mode space can be divided into subspaces representing the lower and higher order modes. Sufficient aperture yields orthogonal and linearly independent subspaces and a linear algebraic process yields orthogonalized subspaces with reduced aperture. Received data is then projected onto these subspaces and a discrimination statistic is formed. This work examines the application of this process to data from the REP11 experiment in terms of performance of the discriminator over different sets of data and levels of environmental knowledge. Work sponsored by ONR Undersea Signal Processing.
Sound speed estimation and source localization with particle filtering and a linearization approach
Authors: Lin Tao , Michalopoulou Zoi-Heleni
Published: September 2012

In previous work, a particle filtering method was developed that provided estimates of multipath arrival times from short-range data and, subsequently, employed them in geometry, bathymetry, and sound speed inversion. The particle filter provided probability density functions of arrival times, that were then “propagated” backwards through a sound propagation model for inversion. That implies that every particle from the probability density is employed in the inversion scheme, creating a potentially computationally cumbersome process. In this work, we develop a new method for such parameter estimation which relies on linearization. The novel aspect is that the Jacobian matrix now includes derivatives with respect to Empirical Orthogonal Function coefficients. The approach, requiring only a few iterations to converge, is particularly efficient. Results from the application of this technique to synthetic and real (SW06) data are presented and compared to full-field inversion estimates. [Work supported by ONR and the NSF CSUMS program.]
Automated entropy-based bird phrase segmentation on sparse representation classifier
Authors: Wang Ni-Chun , Tan Lee Ngee , Hudson Ralph E. , Kossan George , Alwan Abeer , Yao Kung , Taylor Charles E.
Published: September 2012

An automated system capable of reliably segmenting and classifying bird phrases would help analyze field recordings. Here we describe a phrase segmentation method using entropy-based change-point detection. Spectrograms of bird calls are often very sparse while the background noise is relatively white. Therefore, considering the entropy of a sliding time- frequency window on the spectrogram, the entropy dips when detecting a signal and rises back up when the signal ends. Rather than a simple threshold on the entropy to determine the beginning and end of a signal, a Bayesian recursion-based change-point detection(CPD) method is used to detect sudden changes in the entropy sequence. CPD reacts only to those statistical changes, so generates more accurate time labels and reduces the false alarm rate than conventional energy detection methods. The segmented phrases are then used for training and testing a sparse representation(SR) classifier, which performs phrase classification by a sparse linear combination of feature vectors in the training set. With only 7 training tokens for each phrase, the SR classifier achieved 84.17% accuracy on a database containing 852 phrases from Cassins Vireo (Vireo casinii ) phrases that were hand-classified into 32 types. [This work was supported by NSF.]
Mitigation of underwater piling noise by air filled balloons and PE-foam elements as hydro sound dampers
Authors: Elmer Karl-Heinz , Gattermann Jörg , Kuhn Christian , Bruns Benedikt
Published: September 2012

Founding of offshore wind turbines by pile driving induces considerable underwater sound emissions that are potentially harmful to marine life. In Germany, the Federal Maritime and Hydrographic Agency (BSH) has set a standard level of 160 dB (SEL) at a distance of 750 m from pile driving. Effective noise reducing methods are necessary to keep this standard level. The new method of hydro sound dampers (HSD) uses curtains of robust air filled elastic balloons showing high resonant effects, similar to air bubbles, but also balloons with additional dissipative effects from material damping and special dissipative PE-foam elements to reduce impact noise. The resonance frequency of the elements, the optimum damping rate for impact noise, the distribution and the effective frequency range can be fully controlled, if the HSD-elements are fixed to pile surrounding fishing nets. HSD-systems are independent of compressed air, not influenced by tide currents and easy adaptable to different applications. The theoretical background, numerical simulations, laboratory tests and offshore tests of HSD-systems result in noise mitigations between 17 dB to 35 dB (SEL). The work is supported by the German Federal Environmental Ministry (BMU).
Shipping source level estimation for ambient noise forecasting
Authors: Rogers Jeffrey S. , Means Steven L. , Wales Stephen C.
Published: September 2012

The ability to accurately estimate shipping source levels from ambient noise data is an essential step towards creating a forecast model of the ocean soundscape. Source level estimates can be obtained by solving the system of linear equations, governed by the sonar equation, that relate source level to transmission loss (TL) and beamformer response. In this formulation, beamformer response is known and TL can be modeled from ship positions that are determined by a fusion of automatic identification system (AIS) reports and local radar data. Different levels of environmental realism will be taken into account for the TL model by considering two ocean bottom profiles. In particular, a layered sand-limestone bottom and karst sand-limestone bottom will be used in comparison for both 2D and NX2D TL runs. Source levels must be constrained to be positive and are thus solved for with a non-negative least squares (NNLS) algorithm. Estimation of source levels on data collected during the 2007 shallow water array performance (SWAP) experiment will be presented. Simulated ambient noise forecasts for the different sediment profiles will then be compared to real data from the SWAP experiment. [This work was supported by ONR.]
Prediction of noise levels on accelerometers buried in deep sediments
Authors: Sanders William , Bibee Leonard D.
Published: September 2012

The noise field below 100 Hz for three-axis accelerometers buried in sediments is due primarily to shipping, and to a lesser extent wind. Both are generated near the surface. Hence a buried sensor observes noise from an area of the sea surface around it extending theoretically across the entire ocean. However, practically more distant noise sources diminish (even though the area increases with the square of the distance) with range so as to limit the “listening area”. Sensors buried in sediments cut off horizontally propagating noise and hence are relatively more sensitive to locally generated noise. An elastic parabolic equation model is used to model the responses of three axis accelerometers buried in sediments within a complex geologic environment. The effect of shear waves in surrounding structures are shown to significantly affect the noise field. Noise from distant sources received by buried sensors is shown to be as much as 20 dB lower than that on sensors in the water column.
Using hydroacoutic stations as water column seismometers
Authors: Yildiz Selda , Sabra Karim , Kuperman W. A. , Dorman LeRoy M.
Published: September 2012

The Comrehensive Nuclear-Test-Ban Treaty Organization (CTBTO) maintains hydrophones that have been used to study icebergs and T-wave propagation. These stations consist of three hydrophones at about the depth of sound channel in a horizontal triangle array with 2 km sides. We have used data from these stations in the few tenths of a Hertz and below regime to study if we can effectively use these stations as water column seismometers. Among the processing performed was methods to effectively transform the hydrophone configurations to vector sensors. An assortment of signal processing on hydrocoustic data from the December 26th 2004 Great Sumatra Earthquake has been compared to seismograph data of the same event indicating, that the hydrophone stations can indeed be used as surrogate seismometers.
Acoustic insertion loss measurement using time reversal focusing
Authors: Li Jianlong , He Zhiguang
Published: September 2012

Accurate measurement of acoustic insertion loss has important applications in evaluating the performance of acoustic filtering material. In a typical procedure for insertion loss measurement, two pulses are recorded: one without and one with the specimen inserted between the transmitters and receivers. The amplitude spectra of the two pulses are then used to determine the insertion loss, which is a function of frequency. The measurement with low frequencies is quite difficult because of the reverberation interference, which is induced by the sides of vessel where the absorption materials cannot work well and fail to produce an acoustic free field environment. This presentation presents a method which uses time reversal (TR) focusing technique to measure the insertion loss of acoustic filtering materials. The experiment results in a waveguide water tank show that the approach can achieve high signal-to-reverberation ratio in the measurement. Besides, TR focusing provides high resolution at the place of the specimen which reduces the requirement of the specimen size. [Work supported by the National Natural Science Foundation of China under grant no 61171147.]
Using spherical microphone array beamforming and Bayesian inference to evaluate room acoustics
Authors: Clapp Samuel , Botts Jonathan , Guthrie Anne , Xiang Ning , Braasch Jonas
Published: September 2012

The most well-known acoustical parameters - including Reverberation Time, Early Decay Time, Clarity, and Lateral Fraction - are measured using data obtained from omnidirectional or figure-of-eight microphones, as specified in ISO 3382. Employing a multi-channel receiver in place of these conventional receivers can yield new spatial information about the acoustical qualities of rooms, such as the arrival directions of individual reflections and the spatial homogeneity. In this research, a spherical microphone array was used to measure the room impulse responses of a number of different concert and recital halls. The data was analyzed using spherical harmonic beamforming techniques together with Bayesian inference to determine both the number of simultaneous reflections along with their directions and magnitudes. The results were compared to geometrical acoustic simulations and used to differentiate between listener positions which exhibited similar values for the standard parameters.
Two home-brewed microphone assemblies for performing arts spaces
Authors: Conant David
Published: September 2012

Two decades ago, MCH pressed into service a binaural head (rather identical to one of its principals) comprised of a human skull, paraffin wax and anatomically-correct pinnae. This has been found useful in our concert hall tuning exercises. Separately, during tuning exercises, acousticians on our team reported possible percussion echoes during amplified events at Los Angeles' new 1700-seat Valley Performing Arts Center. Anticipating a deeper forensic exercise rapidly looming, a highly directional parabolic microphone system was cobbled from ad hoc parts to quickly confirm (or not) the reports, identify problem surfaces and potential solutions, if required. The curious-appearing, but effective devices are described and their use discussed.
Analysis of concert hall acoustics using time-frequency and time-spatial responses
Authors: Pätynen Jukka , Tervo Sakari , Lokki Tapio
Published: September 2012

A set of objective parameters (ISO3382-1:2009) is widely used for describing acoustic conditions in performance spaces. With few exceptions, they are based on integrating sound energy within moderate time intervals. In practice, different acoustic conditions can yield similar values for objective measures. A presented method of analyzing concert hall acoustics with respect to the time-frequency features aims to overcome the deficiencies of the objective parameters by conveying considerably more information in an uncomplicated form. This is achieved by visualizing the contribution of short time frames in the impulse response to the cumulative sound energy as a function of frequency. Particularly the early part of the room impulse response, including the influence of the seat dip effect is efficiently visualized. The method is applied to acoustic measurements conducted at five corresponding positions in six concert halls. It is shown that in addition to communicating standard monaural objective parameters, the visualizations from the method are connected with several features regarding the subjective impression of the acoustics. The time-frequency analysis is further extended into utilizing a recent sound direction estimation technique. Resulting time-directional visualization enables the accurate analysis of early reflections and their contribution to spatial sound.
The importance and feasibility of “Reflectivity” as an index applicable for architectural acoustic design
Authors: SanSouci Sooch , Doggett Felicia
Published: September 2012

A major part of room acoustics concerns sound control within a space. This traditionally involves reverberation control, music envelopment, optimization of speech comprehension and privacy, noise control, spatial enhancement, modal and reflection control for rooms used in recording, mixing, editing, mastering, and measuring sounds and hearing. In all of these examples, room acoustics is influenced by early reflections from the interior surfaces, objects and geometry. The impedance of a surface generally varies in relation to the incident angle of sound waves, therefore knowing the true reflectivity of surfaces would be complimentary to sound decay time and absorption coefficients. This presentation reviews current trends in the measurement of sound reflectivity as well as many of the challenges involved in developing an approved laboratory measurement methodology. Not only a potentially important tool for acousticians, architects and designers, but a formally adopted “Reflectivity Index” would aid product design, research, and education in room acoustics. Examples of comparative measurements of materials ranging from porous media to continuous or perforated surface assemblies are examined and how the range of results might be unified as a single metric.
STI measurements in real time in occupied venues
Authors: Ahnert Wolfgang , Feistel Stefan
Published: September 2012

To measure impulse responses in rooms and free fields is a daily Job for acousticians but mainly this is done in unoccupied cases. Results for the occupied case are derived by use of simulation software or by estimations based on experience. Using a newly developed multithread algorithm speech, music or any other signals from a microphone input and from a mixing console can be utilized to obtain impulse response data for further evaluation. In a soccer stadium in presence of more than 50.000 visitors the measurements have been done even as a function of the degree of occupancy. The method will be explained in detail and the needed conditions are described. All factors of influence are discussed to obtain results to derive impulses responses and to calculate the STI values in post processing.
Non-traditional in-room measurement and non-measurement approaches to existing room evaluations
Authors: Schuette Dawn , Giegold Carl , Norris Molly
Published: September 2012

Threshold Acoustics has experimented with a number of non-traditional approaches to the evaluation of existing interior spaces in recent years. These methods have varied widely in response to the unique circumstances of each project. The challenges and advantages of each room must be approached with an open mind, in terms of both measured and qualitative evaluation, to reach a firm understanding of the acoustic character of a space. This paper will discuss studies that have utilized techniques as diverse as theatrical lighting and gels as a means of fine-tuning ceiling reflectors to working directly with musicians to determine how rooms as a whole or, in some cases individual room elements, respond to the frequency content and directionality of specific instruments. We will also discuss the method involved in a recent study of the interaction between a room and its reverberation chambers that was performed to gain a more complete understanding of the complex ways they influence one another.
Recent experience with low frequency room acoustics measurements
Authors: Gulsrud Timothy E.
Published: September 2012

Despite the fact that both orchestral and popular music contain important low frequency (i.e., below 100Hz) sound energy, room acoustics measurements and parameters for concert halls do not typically consider the frequency range below the 125Hz octave band. This has resulted in inadequate objective descriptors of bass response and, in some cases, misguided acoustic designs to obtain good bass response. In this paper we present low frequency data measured in several concert halls around the world and discuss various methods for acquiring and analyzing the data, with the aim of encouraging further research in this area.
Evaluation of room-acoustic modal characteristics from single-point measurements using Bayesian analysis
Authors: Henderson Wesley , Xiang Ning , Botts Jonathan
Published: September 2012

Room mode analysis is an important element of architectural acoustic design. In small rooms especially, well-separated low frequency room modes can cause unpleasant aural effects, such as undesirable resonances and flutter echoes. Traditional room mode analysis is generally done using the discrete Fourier transform. This work proposes a time-domain modal analysis method by which the amplitudes, frequencies, and damping constants of the room under test can be directly determined for low modal frequencies by using a Bayesian inference algorithm on a single room impulse response (RIR). The method’s time-domain, model-based approach allows the number of modes present in the RIR, as well as the amplitudes, frequencies, and damping constants for each mode, to be determined using Bayesian model selection and parameter estimation, respectively. The method uses Skilling’s nested sampling algorithm to infer parameter values. Results indicate that the method is especially useful in rooms with closely-spaced modes at low frequencies.
A comparison of source types and their impacts on acoustical metrics
Authors: Siebein Keely
Published: September 2012

The purpose of this study is to compare acoustical measurements made with different source types in a relatively reverberant room to determine if ISO 3382 monaural acoustic parameters such as Reverberation Time (RT), Early Decay Time (EDT), and Clarity Index (C80), yield different results for natural acoustic source stimuli. The source stimuli used in the study included Maximum Length Sequences (MLS), a running train of speech, a running piece of music and a balloon pop. The scientifically calibrated method is then compared to acoustical measurements obtained from natural acoustic sources, which include anechoic recordings of voice and music played through a directional speaker in the front of the room to simulate activities that would normally take place in the room, such as a person speaking and music being played during a worship service. This analysis is performed to determine if there are differences in acoustic room parameters using natural acoustic sources. This study essentially compares the effects of different source stimuli on measured acoustic parameters. It was found that different source signals and receiver locations significantly affect the acoustic metrics derived from the acoustical measurements due to variations in frequency, level and directionality.
Measurements of the just noticeable difference for reverberation time using a transformed up–down adaptive method
Authors: Buck Adam , Blevins Matthew G. , Wang Lily M. , Peng Zhao
Published: September 2012

This investigation sought to measure the just noticeable difference (JND) for reverberation time (T30) using a rigorous psychophysical method, namely the transformed up-down adaptive method. In ISO 3382-1:2009, the JND for reverberation metrics is taken to be 5%, based on work by Seraphim (1958); however, others have suggested that the actual JND is higher. In this project, sound samples with varying T30 were auralized from impulse responses simulated in a realistically modeled performance space using ODEON. The model’s absorption coefficients were uniformly varied across all surfaces and frequencies to achieve the desired T30s. Three reference reverberation times were utilized (one, two, and three seconds), and eight T30 cases spaced at 4% intervals both above and below each of the three reference T30s were created. Auralizations using a 500 ms white noise burst were presented in a computer-based testing program running a three-interval one-up two-down forced choice method, presented in a sound booth over headphones with flat frequency response. The program randomly interleaved six staircase sequences, three of which ascended and three of which descended towards each reference T30. Results averaged across 30 participants will be presented. [Work supported by a UNL UCARE Grant and the ASA Robert W. Young Award.]
The role of acoustical characteristics for enhancement of acoustic comfort in high-speed train passenger cars
Authors: Jang Hyung Suk , Hong Jooyoung , Jeon Jin Yong
Published: September 2012

The room acoustic environments in high-speed trains have been investigated to identify the design elements for the passenger cars to improve acoustic comfort. Both room acoustical and psychoacoustical parameters affected by the absorption coefficients of interior finish materials were measured at the height of passengers’ ears. Room acoustical simulation was constructed based on the measurements to investigate the effect of design elements influencing acoustic quality in the carriage. Through computer simulation of the models with changes in acoustical properties such as absorption/diffusion coefficients of the interior surfaces, the effect of interior design components were investigated and classified to improve the speech privacy.
Results of a scaled physical model to simulate impact pile driving
Authors: Woolfe Katherine F. , Hastings Mardi C.
Published: September 2012

To achieve a more complete understanding of the parameters involved in the structural acoustics of impact pile driving, a scaled physical model was developed and tested. While the design of the scaled model has been presented previously (Woolfe et al., JASA 130: 2558, 2011), this presentation focuses on analysis of wall velocity data and intensity data obtained from experimental evaluation of the model. The energy contained in a control volume surrounding the pile and the energy exchanged across the surface of the control volume were estimated from near field intensity measurements. The amount of energy transferred to the fluid from the cylindrical shell structure during impact and the amount of energy transferred to the structure from the fluid immediately following impact were determined. Results indicate that the highly damped pressure waveform as observed in the water column of the scaled physical model as well as in field data is due primarily to the transfer of energy from the surrounding water back into the structure. [Work supported by the Georgia Institute of Technology and the Oregon Department of Transportation through a subcontract from Portland State University.]
Dynamic response of a fish swim bladder to transient sound
Authors: Shahab Shima , Hastings Mardi C.
Published: September 2012

High-level underwater sound exposures from impact pile driving activities and seismic air guns can cause physical damage to fishes. Damage to biological tissues depends on the strain rate induced by the initial rapid rise and fall times of the received sound pulse. So a time-domain analysis is needed to understand mechanisms of tissue damage resulting from exposure to sound from transient acoustic sources. To address this issue, the frequency domain mathematical model originally developed by Finneran and Hastings (JASA 108: 1308-1321, 2000) was modified to predict the response of a fish swim bladder and surrounding tissues to transient signals. Each swim bladder chamber was modeled as an elastic prolate spheroidal shell filled with gas and connected to other parts of the anatomy. Results of three case studies are presented showing correlation between the strain rate of the swim bladder wall and tissue damage reported in five different species of fish.
Using acoustical monitoring to assess mule deer behavior in response to natural gas development and noise disturbance in the Piceance Basin, Colorado
Authors: Lynch Emma
Published: September 2012

Passive recording units are valuable tools for assessing wildlife behavior, and can be used to address questions on multiple scales, from individual to landscape. We used this versatile technique to explore one of the most pressing wildlife management issues in the intermountain west: broad scale energy development. Much of this development occurs on critical wildlife habitat, and has been shown to alter the physical and acoustical properties of landscapes at a rapid rate. We designed and packaged an inexpensive, collar-mounted recording device for monitoring mule deer (Odocoileus hemionus) behavior with respect to natural gas development in Northwestern Colorado. This presentation will provide a summary of collar design, data analysis, and preliminary results.
Use of acoustics to quantify and characterize bullet overshot into sensitive wildlife areas
Authors: Delaney David , Marston Tim
Published: September 2012

Live-fire training exercises on military installations are known to impact tree health and can potentially affect nesting/foraging habitat and behavior of terrestrial animals, though few studies have attempted to quantify and characterize bullet overshot from military training operations downrange into sensitive wildlife areas. There is concern about the potential impact that downrange military munitions might have on the federally endangered Red-cockaded Woodpecker and its foraging and nesting habitat. Various anecdotal methods have been used in an attempt to document bullet overshot, but none of these methods have been shown to be effective. The objective of this project is to demonstrate that acoustical techniques can accurately and effectively record and characterize live-fire bullet overshot into sensitive wildlife areas downrange of active military ranges. This research is part of a long-term study on Fort Benning, GA to investigate how munitions fire affects Red-cockaded Woodpecker nesting/foraging habitat and nesting behavior, while also investigating the effectiveness of earthen berms at stopping bullets from entering downrange areas. Preliminary results and field protocols will be presented and discussed.
Passive acoustic monitoring of bullfrog choruses: Spontaneous and evoked changes in group calling activity
Authors: Simmons Andrea M. , Knowles Jeffrey M. , Jacobs Eva , Simmons James A.
Published: September 2012

We developed a multiple-microphone array method for recording temporal and spatial interactions of groups of vocalizing male bullfrogs, and for analyzing how this chorusing behavior is perturbed by playbacks of modified frog calls. Chorusing bullfrogs were recorded over 3 nights (90 min sessions) using an array of ten MEMS microphones distributed along a 20-m sector beside a natural pond. Vocal responses were digitized at 50 kHz using Measurement Computing A-to-D boards and customized software on a Lenovo Thinkpad. Individual frogs were located by time-difference-of-arrival measurements at the array. Baseline chorus activity was recorded for 10-20 min before and after playbacks. Playbacks consisted of digitized exemplars of two natural 5-croak advertisement calls, which were manipulated by adding or subtracting spectral components or by introducing masking noise. Baseline chorus activity featured both alternation of calls, mostly between far neighbors, and overlapping of calls, mostly by near neighbors. Bullfrog evoked vocal responses were modified by playbacks of stimuli with altered spectral components, suggesting that the animals perceived these spectral modifications. The array technique indicated that responses of far neighbors were often more strongly impacted by playbacks than those of near neighbors.
Environmental determinants of acoustic activity in Iberian anurans
Authors: Marquez Rafael , Llusia Diego , Beltran Juan Francisco
Published: September 2012

We monitored acoustic activity of populations of anurans (genera Hyla and Alytes) in the Iberian Peninsula (Spain and Portugal) in localities at thermal extremes of their distribution. Logistic and linear regression models revealed that the major social and environmental determinants of calling behavior (chorus recruitment and chorus duration) were similar over most populations. Chorus recruitment was less dependent on environmental factors than chorus duration, which was also influenced by chorus size. Seasonal variation of night temperatures in populations of Hyla showed wide overall ranges (above 11 °C) and gradual increases of the nightly mean (3-12 °C), which was positively associated with the day number in the breeding season. Within days, temperatures were typically close to their daily maximum at sunset, the initiation of calling activity. We compared ranges of calling temperatures among species, populations, and seasons over three years. We showed that calling temperature changed when anuran populations were subjected to different thermal environments. Species had wide calling temperatures ranges across their distribution. Interannual comparisons showed that both terrestrial and aquatic breeding anurans were active during extremely hot breeding seasons. Lower thermal thresholds for the onset of calling were different between conspecific populations, suggesting that other factors are needed to trigger reproduction.
Speckle generation and analysis of speckle tracking performance in a multi-scatter pressure field
Authors: Kalkan-Savoy Ayse , Thompson Charles
Published: September 2012

Speckle tracking imaging is used as a method to estimate heart strain. An analysis of accuracy of speckle tracking and its potential to be utilized in quantification of myocardial stress through estimation of heart motion is examined. Multiple scattering effects are modeled using the Kirchoff integral formulation for the pressure field. The method of Pade approximants is used to accelerate convergence and to obtain temporal varying characteristics of the scattered field. Phantoms having varied acoustical contrast media and speckle density are used in this study. The effectiveness of inter-image frame of correlation methods for estimating speckle motion in high contrast media is considered. (NSF Grant 0841392)
An electro-mechanical model of a carbon nanotube with application to spectrum sensing
Authors: Chandra Kavitha , Chery Armand , Attioui Fouad , Thompson Charles
Published: September 2012

The transduction of resonant mechanical vibrations induced in a single walled carbon nanotube (CNT) with application to frequency and signal detection is investigated in this work. The CNT, clamped between two metallic source and drain junctions and suspended in a trench above a gate electrode behaves as a conducting channel, controlled by appropriate gate and drain voltages. The Euler-Bernoulli model of an elastic beam is applied to model transverse vibrations of the CNT, considering the nonlinear stretching effect of the beam. The solution approach utilizes a Chebyshev-Galerkin spectral expansion and captures the influence of the fundamental and higher harmonic spatial modes when subject to time-harmonic and stochastic loads distributed across the beam. The transverse vibrations of the CNT generate a time-varying capacitance between the CNT and the gate that leads to non-equilibrium potential and charge induced on the tube. A self-consistent approach using a ballistic semi-classical transport model is applied iteratively to compute the charge and current variations at the drain terminal. Application of the system as a signal demodulator is analyzed by mixing the drain current with a matched high-frequency carrier signal that drives the gate terminal.
Bilateral coordination and the motor basis of female preference for sexual signals in canary song
Authors: Suthers Roderick A. , Vallet Eric , Kreutzer Michel
Published: September 2012

The preference of female songbirds for particular traits in songs of courting males has received considerable attention, but the relationship of preferred traits to male quality is poorly understood. There is evidence that some aspects of birdsong are limited by physical or physiological constraints on vocal performance. Female domestic canaries (Serinus canaria) preferentially solicit copulation with males that sing special high repetition rate, wide-band, multi-note syllables, called `sexy' or A-syllables. Syllables are separated by minibreaths but each note is produced by pulsatile expiration, allowing high repetition rates and long duration phrases. The wide bandwidth is achieved by including two notes produced sequentially on opposite sides of a syrinx, in which the left and right sides are specialized for low or high frequencies, respectively. The temporal offset between notes prevents cheating by unilaterally singing a note on the left side with a low fundamental frequency and prominent higher harmonics. The syringeal and respiratory motor patterns by which sexy syllables are produced, support the hypothesis that these syllables provide a sensitive vocal-auditory indicator of a male's performance limit for the rapid, precisely coordinated inter-hemispheric switching, which is essential for many sensory and motor processes involving specialized contributions from each cerebral hemisphere.
The link between cooling mechanical system type and student achievement in elementary schools
Authors: Jaramillo Ana M. , Ermann Michael
Published: September 2012

In aggregate, air-conditioning systems are the largest contributors to classroom noise, and some types of air-conditioning systems are noisier than other types. The impact of noise in human performance has been widely studied and found to be stronger in children. A study of 73 elementary schools in a single Orlando, Florida school district sought to relate mechanical cooling system type with student achievement. It found that for schools populated with students of similar socio-economic background, schools cooling with the noisiest types of mechanical system underperformed on student achievement tests relative to those with quieter types of systems. It also found that schools with the poorest students were more likely to cool their classrooms with noisier systems.
Detection of infrasonic energy from tornado-producing storms
Authors: Talmadge Carrick L. , Fraizer William G. , Waxler Roger , Park Joseph C. , Kleinert Daniel E. , Carter Geoffery E. , Godbold Gerald , Harris David , Williams Chad , Buchanan Hank R.
Published: September 2012

There are numerous reports in the literature on the observation of infrasound emitted from tornadic thunderstorms. Most of these observations have been made from sensors that are several hundreds of kilometers from the location of the storm, and “ground truth” about the tornadic activity is not well established. We report here on a campaign carried out during the summer of 2011 in which 50 infrasound microphones were deployed, as part of an ongoing multi-university program on hazard detection and alert funded by the National Oceanic and Atmospheric Administration. Sensors were placed along the paths of developing tornadic storms. We focus here on a severe weather outbreak that took place near Oklahoma City on May 24, 2011, in which a total of 7 tornados including one F5 and two F2 tornados were produced. Three sensors were located between the paths of an F4 and an F5 tornado, and 11 additional sensors were located northeast of an F4 tornado that generated a 75-km track. Substantial meteorological information, including ground truth about tornados (intensity and size as a function of time), and the relative close proximity of the sensors to the storms, provides us with a level of detail not available in previous storms. We will report on our infrasound measurements and analysis from this outbreak as well as discuss data from two other interceptions of tornadic storms, which occurred on May 30 and June 19, 2011.
The relationship between first language and second language intelligibility in Mandarin-English bilinguals
Authors: Luque Jenna S. , Blasingame Michael , Burchfield L. A. , Matsubara Julie , Bradlow Ann R.
Published: September 2012

Previous research has shown that L1 speech intelligibility, as judged by native listeners, varies due to speaker-specific characteristics. Similarly, L2 speech intelligibility as judged by native listeners also varies across speakers. Given variability in L1 and L2 intelligibility, we hypothesize that, within bilinguals, some speaker-specific characteristics that contribute to variability in L1 intelligibility (e.g., long-term average spectrum, speech rate, and articulatory precision) are language-independent and therefore also contribute to variability in L2 intelligibility. This leads to the expectation that within a group of bilingual speakers, relative L1 intelligibility is a significant predictor of relative L2 intelligibility. In the current study, 14 Mandarin-English bilinguals produced 112 short meaningful sentences in their L1 (Mandarin) and L2 (English). Independent groups of Mandarin and English listeners then repeated back the sentences (native-accented Mandarin productions for Mandarin listeners at -4 dB SNR, Mandarin-accented English productionsfor English listeners at 0 dB SNR). Intelligibility was calculated as proportion of words correctly repeated. L1 intelligibility was a significant predictor of L2 intelligibility (β=.58, S.E.β=.21, p<.05) within these Mandarin-English bilinguals, supporting the hypothesis that language-independent speaker-specific characteristics contribute to both L1 and L2 intelligibility in bilingual speakers.
Cross-linguistic emotion recognition: Dutch, Korean, and American English
Authors: Choi Jiyoun , Broersma Mirjam , Goudbeek Martijn
Published: September 2012

This study investigates the occurrence of asymmetries in cross-linguistic recognition of emotion in speech. Theories on emotion recognition do not address asymmetries in the cross-linguistic recognition of emotion. To study perceptual asymmetries, a fully crossed design was used, with speakers and listeners from two typologically unrelated languages, Dutch and Korean. Additionally, listeners of American English, typologically close to Dutch but not Korean, were tested. Eight emotions, balanced in valence (positive-negative), arousal (active-passive), and basic vs. non-basic emotions -properties that are known to affect emotion recognition- were recorded by eight Dutch and eight Korean professional actors, in a nonsense phrase that was phonologically legal in both languages (and English). Stimuli were selected on the basis of prior validation studies with Dutch and Korean listeners. 28 Dutch, 24 Korean, and 26 American participants were presented with all 256 Dutch and Korean stimuli, blocked by language. Participants indicated for each stimulus which emotion it expressed by clicking on one of the eight emotions or “neutral”. Results showed strong asymmetries across languages and listener groups that cannot be explained along previously described dimensions (valence, arousal, basic-non-basic). The present results call for the extension of theories of cross-linguistic emotion recognition to incorporate asymmetrical perception patterns.