bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for a genetic contribution, and a chromosome 4 locus, to musical aptitude.
Authors: Goring Harald
Published: October 2009

The genetic influences on mental diseases, skills, and behaviors are essentially entirely unknown. We have performed a family study to investigate the genetic etiology of musical aptitude. We focused on three measures of musical aptitude that in our opinion likely are more reflective of innate ability than of musical training: a test for auditory structuring ability [Karma music test (KMT)] commonly used in Finland, and the Seashore pitch and time discrimination subtests (SP and ST, respectively) used internationally. These phenotypes were assessed in 15 Finnish, multigenerational families comprising 234 individuals. Using variance component-based methodology, we obtained significant evidence of a genetic contribution to all phenotypes, with heritability estimates of 42% for KMT, 57% for SP, 21% for ST, and 48% for a combined music test score. To map any underlying major loci, we performed multipoint genome-wide linkage analysis, using 1113 microsatellite markers. We obtained nominally significant linkage evidence on chromosome 4q22 (lod=3.33) for the combined music test score. This locus seems to largely influence KMT, which yielded a lod score of 2.91 in the region. Our results suggest that genetic factors in aggregate influence musical aptitude, with chromosome 4 appearing to harbor a major locus.
The development of domain-specific musical knowledge.
Authors: Hannon Erin
Published: October 2009

Music and speech are both complex sound structures that unfold over time, yet they undoubtedly rely on fundamentally dissimilar perceptual processes and knowledge. Given that naive infant listeners must discover and learn meaningful structures in music and speech in parallel, a natural question to ask is whether early auditory learning is influenced by domain-specific or domain-general constraints. I will discuss two current studies exploring and comparing how infants and adults respond to speech-music similarities and dissimilarities. Because music and speech share certain rhythmic properties, one set of experiments explores the extent to which adults and infants can classify speech and music stimuli based on the rhythm. After being familiarized to low-pass filtered speech or instrumental songs from French-speaking or English-speaking cultures, adults fail to classify novel stimuli across domains (e.g., French and English speech after familiarization to songs), whereas 10-month-old infants succeed. A second set of experiments examines whether infants and adults exhibit domain-specific biases when required to infer rule-like patterns from sound sequences in a linguistic versus musical context (e.g., rules based on syllables versus pitch). Results across both studies indicate that domain-specific knowledge and learning biases may increase from infancy to adulthood.
The genesis of absolute pitch: Theories and experimental findings.
Authors: Deutsch Diana
Published: October 2009

This paper reviews theories and findings concerning the genesis of absolute pitch, defined as the ability to name a musical note without the aid of a reference note. Given the rarity of absolute pitch, there has been much speculation concerning its genesis. Four theories are evaluated: First, absolute pitch can be acquired at any time through practice; second, it is a rare genetic trait which rapidly becomes apparent as circumstances allow; third, absolute pitch is subject to a critical period that is specific to music; fourth, the faculty as generally documented is essentially language-based, and so is subject to the same critical period as are other aspects of language. In this context, the evidence considered that absolute pitch is present implicitly in most individuals, even those who are unable to label musical notes when these are presented in isolation. Findings concerning the neurological underpinnings of absolute pitch are also reviewed.
Factors that have positive or negative influence in the noise levels in the great cities of Mexico.
Authors: Elizondo-Garza Fernando J.
Published: October 2009

In this paper the noise condition in the largest cities of Mexico is described by means of an “analysis of opposed.” The historical, sociocultural, political, economic, and technological factors that have positive or negative influence in the noise generation are considered, which imply a fight of opposites, in such a way that the current situation will be the resultant of all of their influences. By visualizing the noise pollution problem in this way, although not a quantitative approach, represents a very useful qualitative tool, especially to settle down strategies to reduce the noise levels in the cities. Unfortunately, in some cases, the inertia of the negative factors—which are the producers of noise—may cause that, in the short term, some positive proposals to reduce the noise levels may not result feasible.
Regulation of noise in Chile: Progress and challenges.
Authors: Delannoy Jaime , Valdebenito Igor , Quezada Roberto
Published: October 2009

In the past 20 years Chile has shown a growing concern for noise pollution. There are regulations for stationary noise sources and also for the surface public transportation. There was a change in the exchange rate to calculate the dose of noise in occupational environments (from q=5 to q=3). The System of Environmental Impact Assessment sets out to mitigate the potential noise impact of each new project. However, the authorities have not been possible to reach an agreement to regulate noise pollution caused by the construction of buildings. In addition, future noise regulations for airports and for noise of private transport are major challenges for the country.
Shortcomings of the Brazilian standards on community noise.
Authors: Nepomuceno Jose Augusto , Mandu Daniel
Published: October 2009

The Brazilian standard NBR 10151 was revised on 2000 to establish guidance for evaluation of noise in inhabited areas aiming the comfort of community. While this is a technical standard, it is often used as a “federal legislation.” States or cities have their own community noise regulation. The NBR 10151 has shortcomings that should be resolved. For example, there is no mention about parameters as Ldn or percentile levels or about evaluation of tone content or sampling methods. The only evaluation parameter is the LAeq. The urban zones are characterized as “rural,” “residential (restricted) hospital and schools,” “mixed area, mostly residential,” “mixed area, mostly commerce and administration,” “mixed area, mostly recreation and leisure,” and “mostly industrial.” There is no guidance how to apply the classification. There are several communities around factories that would be better classified in other ways. The approach in cities and state legislation differs. Again, there are shortcomings as lack of definitions or vague descriptions in these legislations. The authors discuss the Brazilian standards applied to factories and freight harbor. In these situations the shortcomings made them not helpful at all. The Brazilian standards are compared to international regulations used in these projects.
Negative stiffness metamaterial elements for enhanced material damping capacity.
Authors: Kashdan Lia B. , Haberman Michael R. , Wilson Preston S. , Seepersad Carolyn C.
Published: October 2009

Recent research has shown that the introduction of small quantities (1%–2% by volume) of constrained negative stiffness inclusions into a viscoelastic host material leads to an effective energy absorbing behavior greatly exceeding that of conventional materials [Lakes et al., Nature (London) 410, 565–567 (2001)]. The root cause of this increased absorptive capacity is the ability of the negative stiffness materials to do work on the viscoelastic host when perturbed by an incident disturbance such as a sound wave or vibrational motion [Koutsawa et al., Int. J. Mech. Mater. Des. 5, 29–44 (2007)]. A buckled beam constrained to an S-shaped configuration has a strain energy density at a local maximum and will accordingly display negative stiffness. This negative stiffness behavior is non-transient and broadband in nature. The buckled beam structure is therefore a compelling candidate for the construction of new metamaterials for noise reduction, anechoic coatings, and transducer backing materials. This work presents ongoing research that exploits the geometric freedom provided by selective laser sintering to design and construct bistable beam elements. Design configurations are presented together with dynamic test results quantifying the damping capacity via system transmissibility and the resulting decrease in mechanical quality factor at resonance.
Perceptual adaptation to foreign-accented English.
Authors: Bradlow Ann R.
Published: October 2009

Foreign-accented speech presents an interesting challenge for native listeners due to its deviations from native accented speech along multiple acoustic-phonetic dimensions. Nevertheless, since these deviations arise primarily from interactions of the native (L1) and target (L2) language sound systems, they are highly systematic both within individuals and across talkers from the same L1. Moreover, since numerous features of English are typologically rare (e.g., coda clusters and large vowel inventory), various foreign-accents of English frequently converge on similar specific deviations (e.g., cluster reduction and vowel category conflation). Thus, despite a high degree of deviation from native talker norms, the systematicity of foreign-accented speech should facilitate listener adaptation. We examined adaptation at the level of the individual (talker-dependent), the L1 (talker-independent), and the population (accent-independent). First, we showed variation in the speed and extent of talker-dependent adaptation depending on the talker’s baseline English speech intelligibility. Second, we demonstrated that talker-independent adaptation required exposure to multiple talkers of the accent. Finally, we demonstrated that exposure to multiple accents (e.g., Korean-, Hindi-, Mandarin-, and Romanian-accented English) can facilitate accent-independent adaptation, i.e., adaptation to both a trained accented (Mandarin-accented English) and an untrained accent(Slovakian-accented English). This work builds a strong case for highly flexible speech perception mechanisms.
Perceptual learning of cochlear implant simulated speech: Cognitive findings and clinical implications.
Authors: Loebach Jeremy L.
Published: October 2009

Adaptation to the acoustic world after cochlear implantation requires significant adjustment to degraded auditory signals. The cognitive mechanisms underlying the mapping of such signals onto preexisting internal representations (postlingually deafened individuals), or the formation of novel internal representations (prelingually deafened individuals), are not well understood. Therefore, understanding the mechanisms of perceptual learning is critical to providing efficient training and (re)habilitation for new cochlear implant users. The advent of noise and sinewave vocoders to model the output of a cochlear implant speech processor has increased the tools available to investigate perceptual learning of speech in normal-hearing listeners. A fundamental question is whether training should focus exclusively on speech perception (synthetic approach), or whether training on extralinguistic or nonspeech auditory information (analytic approach) promotes more robust perceptual learning and generalization to novel materials and signals. In this talk, I will present data from two recent studies on the perceptual learning of sinewave-vocoded speech by normal-hearing participants that focused on different levels of linguistic/extralinguistic and nonspeech acoustic information. I will discuss the implications these data have for understanding perceptual learning and the cognitive mechanisms that mediate speech perception.
Disordered speech as a testing ground for listener learning and adaptation.
Authors: Liss Julie M. , Lotto Andrew J. , Lansford Kaitlin
Published: October 2009

Speech production disorders arise from a wide variety of anatomical defects, neurological injury, and disease. Depending on the etiology, the speech manifestations may be quite regularized—in the same way that a foreign accent presents consistently—or highly variable with unpredictable speech interruption and degradation. Indeed, even within an individual speaker, one will find both relatively consistent and variable aspects of speech abnormality. A growing body of literature shows that listeners enjoy intelligibility gains with just brief auditory exposure to disordered speech that is accompanied by lexical feedback, and with repeated unsupervised exposures. These benefits have been shown to be both talker-specific and applicable to groups of people who presumably share relevant acoustic-perceptual speech features. While many of these studies have been designed with an eye toward clinical and communicative implications, there is much to be learned about the mechanisms underlying these perceptual improvements with naturally impoverished speech. The purpose of this presentation is to describe the use of clinical populations as a testing ground for hypotheses of listener learning and adaptation. Speech production disorders particularly lend themselves to the study of episodic memory, rhythmic expectancy, and talker-specific versus talker-general effects. [Work supported by NIDCD, NIH.]
Recent findings on early word recognition and learning: Representational change in adapting to variability in voice, foreign accent, and dialect.
Authors: Schmale Rachel
Published: October 2009

A core aspect of recognizing and learning words is accommodating variable acoustic forms. Thus, to become proficient learners, infants and toddlers must adapt to the inherent variability of speech, where words frequently vary in form depending on a host of talker characteristics (e.g., voice, emotional state, foreign accent, dialect, speaking rate). Four sets of experiments examined the impact of variability in voice, foreign accent, and dialect on the abilities of English-learning infants and toddlers to recognize and learn words. The findings reveal evidence about the flexibility of early representations across development. In the face of subphonemic and suprasegmental variability, young infants and toddlers seem to encode and store fine acoustic-phonetic details about the words they hear, which impedes their ability to recognize and learn dissimilar instances of the same word. Alternatively, older infants and toddlers more readily accommodate extraneous acoustic variability by abstracting across dissimilar word forms, leading to more successful recognition and learning. Although younger children display more difficulty adapting to irrelevant acoustic variation, preliminary findings reveal benefits to exposure to variability in inducing more abstract, flexible representations. [Alejandrina Cristià, Elizabeth Johnson, and Amanda Seidl.]
Optimal adaptive sampling for continental shelf acoustic forecasting.
Authors: Heaney Kevin D.
Published: October 2009

Shallow water acoustic propagation variability is driven by bathymetry and geo-acoustic and oceanographic variabilities. At the shelf-break, the rapid change in bathymetry often leads to a separation of shelf-water with open ocean sea-water, leading to a dynamic shelf-break front. In order to accurately predict ocean acoustic propagation (forecasting), an improved understanding of the dynamic oceanographic features is required. To this end, a system of adaptive sampling, utilizing oceanographic and acoustic measurement systems, dynamic oceanographic models, and data assimilation, is being developed. In this paper we will present the approach to optimal oceanographic glider placement and optimal acoustic measurements for reducing the oceanographic and acoustic forecast uncertainty. The results from three experiments will be presented where oceanographic sampling was combined with acoustic measurements in a region modeled with a high-fidelity dynamical ocean model. [Work supported by ONR Code 32OA and SPAWAR.]
Impact on acoustic propagation by internal waves and tides in the region of shelf and slope.
Authors: Chen Chi-Fang , Chiu Yung-Sheng Linus , Chang Yuan-Ying
Published: October 2009

Internal waves (IWS) and tidal activities were investigated in the South China Sea (SCS) and the northeastern seas of Taiwan. These oceanic processes cause large fluctuations and impact on underwater acoustic propagation. These effects include two-dimensional (2-D) and three-dimensional (3-D) effects. The 2-D and 3-D effects are related to the angle between the directions of sound propagation and IW front. When the IW front are from 20 to 90 deg with respect to the acoustic propagation direction, acoustic mode coupling is the dominant factor which could be sufficiently predicted by the N×2D simulations. Acoustic energy is exchanged between modes and is re-distributed among the water columns. However, when the angles between the wave front and the acoustic wave propagation are 0–20 deg, the horizontal refraction effect dominates over mode coupling and the fully 3-D calculation is needed. The acoustic energy would be refracted, as a consequence, resulting in energy focusing and defocusing. These effects are clearly seen by the series of data collected in the SCS and the region of Northern East of Taiwan. Computer modeling results are used to manifest experiment data results in this research. [This work is supported by National Science Council of Taiwan.]
Simultaneous inversion of seabed and water column sound speed profiles in range-dependent shallow water environments.
Authors: Ballard Megan S. , Becker Kyle M.
Published: October 2009

It is well known that the properties of the water column and seabed affect acoustic propagation in shallow water. As a result, numerous inversion schemes have been developed to estimate environmental properties. Many of these algorithms address the problem of estimating properties of the seabed alone, while assuming properties of the water column are known. An example of such an inversion scheme is perturbative inversion which uses modal wavenumbers to obtain sound speed in the seabed as a function of depth [Rajan et al., (1987)]. The inversion algorithm involves solving an ill-posed problem, with regularization used to stabilize the solution, resulting in a smoothed version of the true sound speed profile. To simultaneously estimate water column and seabed properties, qualitative regularization is used to resolve the discontinuity in the sound speed profile at the seafloor and approximate equality constraints are used to constrain the solution in portions of the water column for which the data alone are insufficient. The primary advantage of simultaneously inverting for water column and sediment sound speed profiles is that poor knowledge of a priori information about water column is not aliased into the solution for the seabed. [Work supported by NDSEG and ONR.]
Sound propagation calculations for dynamic conditions in the East China Sea.
Authors: Michelle Kingsland , Chad Smith , David Bradley
Published: October 2009

Based on the sound field discussed in detail in a companion paper, sound propagation behavior is calculated using the range-dependent acoustic model parabolic equation method. A number of source/receiver depth combinations are examined, for frequencies in the range of 200–1000 Hz, and for ranges to 30 km. Impact of the temporal and spatial dynamics of this coastal shelf region will be discussed. Of particular interest is the variability produced by both internal waves and intrusive water masses. [Acknowledgment of work supported by the Office of Naval Research, Contract No. N00014-08-1-0455.]
Effects of non-adiabaticity in modal propagation through random sound speed perturbations.
Authors: LePage Kevin D.
Published: October 2009

Modal propagation through sound speed fluctuations in shelf environments can be modeled adiabatically or fully coupled through polynomial chaos (PC) expansions of the modal amplitudes or complex phase. The importance of modal scattering versus adiabatic effects is explored for random sound speed fields in the mid-frequency regime. It is shown that the importance of inter-modal scattering is related to the interference wavelength between the modes in relation to the horizontal wavelengths of the sound speed fluctuations as well as the vertical structure of the sound speed fluctuations with respect to the shape of the interacting modes. Modal scattering is also highly affected by the relative amplitudes between the modes with strong scattering into weaker modes. While these effects are well known, the coupled mode PC equations give unique insight into the detailed physics of these controlling factors.
Effect of macroscopic parameters on sound absorption and sound transmission loss of porous materials.
Authors: Shravage Paresh , de’Sa Keith
Published: October 2009

Sound absorbing materials are indispensable nowadays for noise control applications. The acoustical behavior of these acoustic materials is governed by five physical (e.g., porosity, flow resistivity, tortuosity, viscous characteristic length, and thermal characteristic length) as well as three mechanical parameters (e.g., Young’s modulus, Poisson ratio, and loss factor). The characterization of these porous materials is very crucial as it plays a crucial role in design and development stage itself for predicting acoustic behavior of multilayer porous materials for higher sound absorption and transmission loss. This prediction depends on measurement accuracy of macroscopic physical parameters which are very difficult to measure except porosity and flow resistivity, which is the only standardized test until today; also availability of such rigs is also a problem for manufactures as they are available only at specialized test laboratories. This paper presents effect all of these parameters on sound absorption coefficient and transmission loss of the porous materials using Johnson–Champoux–Allard and Biot model for poroelastic materials. It also discusses results of simulation with effect of each parameter on acoustic behavior of the sound absorbing materials.
The effects of nonideal microphone directivity patterns on directional impulse response measurements.
Authors: Esplin J. James , Thornock Brian T. , Leishman Timothy W.
Published: October 2009

An acoustician can identify and treat problematic surfaces to reduce or eliminate unwanted reflections only if he knows the origins of those reflections. Several measurement techniques exist for the purpose of identifying these origins, including the Polar ETC method, which requires six cardioid impulse response measurements along Cartesian axes. This presentation will explore two implementations of the method using either a microphone positioner and six sequential cardioid measurements (as originally intended) or four simultaneous measurements from a tetrahedral subcardioid microphone array (originally intended for Ambisonic recordings, but also usable to synthesize the six cardioid measurements). It will compare the two approaches and investigate typical errors introduced by nonideal cardioid directivity patterns. The presentation will also discuss the capabilities of a new method, based on a Cartesian array of seven omnidirectional microphones, and explore the effects of nonideal omnidirectional patterns.
An inexpensive approach to measure one-third octave reverberation times.
Authors: Holdhusen Mark H.
Published: October 2009

Reverberation time is a common measurement taken in room acoustics. However, the software used in portable sound-level meters can be rather expensive, making it challenging for those on a smaller budget to take these necessary measurements on site. The work here outlines an inexpensive method to instantaneously measure one-third octave reverberation times using a portable experimental setup. The setup consists of a PCB random-incidence microphone along with a National Instruments USB data acquisition system and a notebook PC. Using LABVIEW along with MATLAB software, code was written to process acoustic measurement data to achieve one-third octave reverberation times with almost no additional processing time. The entire setup costs approximately 2000 dollars with educational discounts. This setup and procedure give similar results to the aforementioned sound-level meters, but at a fraction of the cost.
Statistical spectrogram modeling and analysis for blind estimation of room acoustics from musical recordings.
Authors: Ren Gang , Bocko Mark F. , Headlam Dave
Published: October 2009

An algorithm employing Markov random field modeling has been applied to spectrographic representations of musical recordings to uncover acoustical features of the recording environment. For recorded music, the reverberation pattern is most visible at the onset/offset edges of harmonic components in the spectrogram. Edge features extracted through image analysis algorithms can be mapped to the acoustical features of the recording space, but the correspondence is complicated by the inherent randomness of the musical “test signal.” This is exacerbated in the media production process because a final mix can be generated from separate recordings from multiple acoustic spaces. The Markov random field modeling algorithm utilizes data-modeling techniques to estimate the probabilistic links between edge analysis results and room acoustical features and further to identify the probabilistic nature of any time-variation in latent room acoustics. Our algorithm obtained enhanced room acoustics feature extraction performance by allowing a gradual refinement of the room acoustics feature vectors through dynamic fusion of prior estimates and knowledge from current musical segments. This on-line approach is also more computationally efficient compared to batch processing. Multiple variants of the proposed algorithm are demonstrated and compared to existing blind room acoustics parameter estimation methods.
Evaluating the practical performance and benefits of various loudspeaker styles for party wall and floor/ceiling assembly field sound transmission testing.
Authors: Hale Marlund E.
Published: October 2009

The instrumentation and equipment used in field sound transmission testing of multi-family residence party walls and floor ceiling assemblies have steadily improved. ASTM E336 suggests the use of omnidirectional speakers for such performance tests. When directional box speakers are used, they need to be placed in and face toward a corner of the sound source room. Since many multi-family residential complexes are two stories and higher, the need to move heavy equipment (including massive speakers) from room to room and floor to floor can be a challenge. It is therefore desirable to optimize weight and performance. This paper compares the functionality and performance of the standard directional box-type loudspeaker (90 dB at 1 m, 350-W maximum input, 90 lbs), an omnidirectional dodecahedron spherical loudspeaker (110 dB at 1 m, 480-W maximum input, 30 lbs) and a prototype omnidirectional dodecahedron spherical loudspeaker (120 dB at 1 m, 1000-W maximum input, 35 lbs). In addition to comparing the acoustical output of these different loudspeaker systems, their tendency to introduce vibrations into the source room floor is also discussed.
Subjective evaluation of low-frequency impact sounds on floor-ceiling assemblies.
Authors: Gover Bradford , Bradley John , Nightingale Trevor , Zeitler Berndt
Published: October 2009

To investigate meaningful ratings and criteria for the acoustical performance of building partitions, it is necessary to understand the subjective judgments of listeners when hearing transmitted or radiated sounds. Impact sounds on floors caused by footstep noise (walking, running, etc.) are particularly bothersome and are not well characterized. A series of recordings of the sound radiated into the room below a floor-ceiling test assembly when an impact occurs on the topside of the assembly (floor surface) is ongoing. The primary impact sources considered are real adult walkers, and a heavy rubber ball, standardized in JIS A 1418-2. The binaural recordings are presented to listening test participants, who rate subjective attributes of the sounds such as annoyance. In this way the floor-ceiling test assembly is rated (and can be ranked) subjectively, and metrics derived from purely physical measurements can be assessed and interpreted. Preliminary results from measurements on a range of lightweight wood framed assemblies are discussed.
Insertion loss: Train and light-vehicle horns and railroad-crossing sound levels.
Authors: Brach Raymond M. , Brach Matthew
Published: October 2009

Studies and analyses of sound levels inside road vehicles frequently require estimation of the sound levels of moving or changing positions of the source (such as a train horn) and receiver (road vehicle). The study presented here focuses on two of the components of the sound transmission from the source to the interior of an automobile. One part of this paper is the development of a method to predict the attenuation of the sound level over the path from the source to the vehicle. The method is based on the classical sound decay equation (including variable directivity and theoretical 6-dB drop-off per doubling of distance) but is modified to accommodate different drop-off rates including experimentally measured values. An example using a typical train horn sound power level is provided. The second portion of the sound path covered in this paper is the attenuation of the sound level due to transmission through vehicle bodies and relates to annoyance of vehicle exterior noise. Insertion loss values and insertion loss spectra are measured for seven different light vehicles. An unusual property of insertion loss spectra is observed and studied. It is shown that direct subtraction of measured band-filtered levels can provide misleading overall levels. A method of correction of the spectrum is presented.
The complex auditory scene at leks: Female perception of and response to male aggregations and predators in the acoustic Lepidoptera.
Authors: Greenfield Michael D. , Alem Sylvain
Published: October 2009

The fundamental mechanisms by which females respond to and choose males based on the parameters of their calling and courtship songs are now rather well understood in many acoustic insects and anurans. However, they remain relatively unexplored in more complex, natural settings, where displaying males may gather in leks of varying size. We addressed several aspects of this problem in an acoustic moth, Achroia grisella (lesser waxmoth; Lepidoptera: Pyralidae), where females show response thresholds and preference functions based on the pulse rate and pulse amplitude of male song. We report that females adjust to increasing lek size by lengthening their exploration trajectories while maintaining the same level of evaluation of each male. We then discuss the potential indirect (genetic) benefits that may accrue to females from their behavioral adjustments. The “auditory scene” at leks may include the sounds of natural enemies (echolocation calls of various species of gleaning bats) as well as displaying males. We note how female A. grisella discriminates between conspecific males and potential predators, both of which broadcast in the same (ultrasonic) frequency band. We then show how females perceive and respond to the full auditory scene and adjust their evaluation of males when visiting leks at which (synthetic) bat echolocations are heard.
Birds and models: Not as different as you might think.
Authors: Sturdy Christopher B. , Dawson Michael R. W. , Guillette Lauren M. , Nickerson Carly M. , Farrell Tara M. , Hoeschele Marisa , Bloomfield Laurie L. , Charrier Isabelle
Published: October 2009

For some time, the Sturdy laboratory group has been studying chickadee vocal production and perception using a variety of approaches. These include, among others, bioacoustic analyses of vocalizations, operant conditioning studies, and, more recently, artificial neural networks. This multidisciplinary approach has been very fruitful. The addition of artificial neural networks to the standard empirical approaches has significantly enhanced the understanding of songbird behavior and has provided models of bird operant conditioning behavior, perception, and cognition, allowed the investigation of questions that would be difficult to carry out with animal studies, honed research questions and foci, and has inspired further empirical studies. This talk will provide a longitudinal review of these and related research findings capitalizing on this data-model/model-data interplay. Topics discussed will include models of bird note type perception, models that have directed the formation of hypotheses about important perceptual features in note types, and models that have inspired further empirical studies of note type perception and have been used to explore a classic cognitive phenomenon, peak-shift, in a multimodal, note-type continuum.
A test of Gestalt grouping principles in frogs: Auditory illusion or sensory bias?
Authors: Bee Mark A. , Seeba Folkert
Published: October 2009

The study of auditory illusions has been important in elucidating the rules of auditory grouping in humans, which adheres to principles first described by Gestalt psychologists to explain the formation of visual objects. For example, the human auditory system perceptually restores short, deleted segments of speech and other sounds (e.g., tones) when the resulting gaps are filled by a potential masking noise. Results from studies of such illusions suggest that the Gestalt principle of “continuity” allows humans to perceive complete auditory objects in the face of incomplete or degraded acoustic information in the presence of noise. The present study tested the hypothesis that female treefrogs experience the perceptual restoration of discrete pulses in the male sexual advertisement signal when they are deleted and replaced by a potential masking noise. While added noise restored some attractiveness to degraded signals, there was no evidence that the frogs experienced the illusion of perceiving actual pulses that were missing. Instead, the added noise functioned as an acoustic ornament that made some signals more attractive than others as a result of an inherent sensory bias for greater sensory stimulation. Whether such sensory biases themselves adhere to Gestalt principles of auditory grouping remains to be demonstrated.
Behavioral measures of auditory streaming in humans and ferrets.
Authors: Micheyl Christophe , Ma Ling , Yin Pingbo , Shamma Shihab , Oxenham Andrew J.
Published: October 2009

The perceptual organization of sound sequences into auditory streams, or “auditory streaming,” is an essential component of the analysis of acoustic scenes by humans and other animals. The development of behavioral paradigms for measuring auditory streaming in human and non-human listeners is an important step toward a better understanding of the similarities and differences in sound perception between humans and other species. In this talk, we will present the results of recent studies performed in collaboration between our groups at the universities of Minnesota and Maryland concerning performance-based measures of auditory streaming in humans and ferrets. In particular, we will describe two complementary temporal discrimination tasks, one of which can be used to induce and measure stream segregation, while the other can be used to promote and measure stream integration in a listener. Because these tasks use similar stimuli, they are especially suitable for use in studies of neural correlates of streaming percepts without stimulus confounds. In addition, we will describe the results of behavioral measures of auditory streaming and informational masking in ferrets, using stimuli and tasks that were directly inspired by psychoacoustical experiments in humans. [Work supported by NIDCD R01 DC 07657.]
Network interactions and the emergence of representations for natural communication signals.
Authors: Gentner Timothy
Published: October 2009

Current understanding of experience dependent plasticity in sensory cortices turns on the notion that as signals acquire behavioral relevance, they elicit increasingly robust neural responses in single cells and/or drive increasingly large neural populations. Similar facilitative effects are seen in the songbird auditory forebrain region CMM when birds learn to recognize conspecific songs. Here, I describe a discrete population of neurons in the adjacent auditory region NCM where the opposite occurs. Following song recognition training, learned songs elicit significantly lower extracellular responses from single NCM neurons than do unfamiliar songs. Moreover, this effect is directly tied to associative learning, as control songs presented in the absence of behavioral contingencies also elicit robust responses. These findings are consistent with an active role for (1) broad scale response suppression and (2) contributions from irrelevant signals in shaping the learned sensory representation for natural, spectro-temporally complex, acoustic communication signals.
Range is pitch, shape is pitch: How much of biosonar is adapted from passive hearing?
Authors: Simmons James A.
Published: October 2009

Echolocating big brown bats perceive target range from overall echo delay. Neuronal networks acting as delay-lines retain the volley of spikes evoked by each broadcast for coincidence-comparisons with volleys of spikes evoked by echoes. These circuits are similar to delay-line/coincidence-detectors proposed for determining periodicity pitch of unresolved frequency components. Bats use resolved frequency components to detect harmonic coherence as the criterion for deciding whether multiple-harmonic sounds are true echoes. These circuits involve FM1-FM2 facilitatory neurons in circuits similar to what has been proposed for spectral pattern matching based on detection of coincidences of spikes at harmonic frequencies, another route for extracting periodicity pitch. Additionally, bats perceive small range separations between target glints from the frequencies of spectral notches produced by interference between overlapping reflections at small time offsets. This psychophysical effect is similar to determining the pitch of comb-filtered noise using neuronal circuits for identifying modulation-rates of rippled spectra. Neuronal circuits for detecting nulls at specific frequencies in echoes yield responses tuned to specific glint separations in time. Bats may use the different mechanisms proposed for determining the pitch of pulse trains, complex sounds, and rippled noise to perceive integrated images of targets. [Work supported by ONR and NIMH.]
Auditory streaming of birdsong in budgerigars and zebra finches.
Authors: Garcia Kristen A. , Rajaram Siddarth , Sen Kamal , Shinn-Cunningham Barbara G. , Dent Micheal L.
Published: October 2009

The ability to segregate or group together sounds accurately in the environment is vital to the survival of all animals and should be highly conserved across many different species. To date, evidence of auditory streaming has been shown in a wide range of organisms, from insects to birds to primates, but these studies have usually used simple stimuli emitting from only one location. The current study utilizes categorization techniques to determine the role of intensive, spatial, temporal, and spectral cues on streaming in budgerigars (Melopsittacus undulatus) and zebra finches (Taeniopygia guttata). Both species were trained to differentially peck keys in response to either a synthetic zebra finch song consisting of five syllables (whole song) or to the same song with the fourth syllable omitted (broken song). Probe trials were then inserted, where possible cues for streaming were tested by altering characteristics of the fourth syllable. Preliminary results showed that the birds were most likely to report hearing a whole song when the fourth syllable in the probe trials was played closer in space, at the same intensity, and with the same spectral characteristics as the rest of the song, suggesting that these cues are important for auditory streaming in birds.
Hamiltonian formalism and cellular algorithm for modeling large numbers of interacting bubbles.
Authors: Thomas Derek C. , Ilinskii Yurii A. , Hamilton Mark F.
Published: October 2009

Large, dense clusters of bubbles play an important role in the efficacy of shock-wave lithotripsy. Although methods exist for simulating bubble interaction dynamics within a cluster, for moderately sized clusters (∼1000 bubbles), they are computationally expensive and scale poorly to larger clusters. Currently under development is a method to reduce the computational complexity of the problem and permit direct simulation of large bubble clusters. The algorithm functions by partitioning the cluster into small cells. Bubble interaction within each cell is assumed to be instantaneous and is modeled using a Hamiltonian formulation [Ilinskii et al. J. Acoust. Soc. Am. 121, 786 (2007)] that has been extended to include a correction for radiation damping. The cellular sub-clusters are coupled via the pressure field they generate, and the time delays associated with finite acoustic propagation speed are taken into account. Use of the Hamiltonian formulation reduces computational complexity and numerical error for clusters containing large numbers of bubbles, and it is thus well suited for application to lithotripsy. The accuracy of the method will be validated by comparison with results obtained from an existing model obtained using Lagrangian formalism. [Work supported by the ARL:UT McKinney Fellowship in Acoustics and NIH DK070618.]
The acoustical apparatus of Rudolph Koenig.
Authors: Greenslade Thomas B.
Published: October 2009

Rudolph Koenig was the pre-eminent maker of acoustic apparatus for research and instruction in the last third of the 19th century. His apparatus is still to be found in lecture demonstration collections in many physics departments in North America. Much of the apparatus that he brought to Philadelphia to display at the Centennial Exhibit 1876 remained on these shores, with part going to the United States Military Academy at West Point, and the remainder to the Physics Department at the University of Toronto. I have visited these collections and many others to photograph many examples of the apparatus that he designed and sold to generate and analyze acoustic signals.
Chladni patterns to holograms: Apparatus for modal analysis of vibrating plates.
Authors: Morrison Andrew , Rossing Thomas
Published: October 2009

Since Chladni popularized the use of powder patterns in the 18th century, they have been widely used to display and analyze the modes of membranes, plates, and other vibrating structures. Although Chladni patterns have been largely replaced by optical and computer methods for modal analysis, most physics apparatus shelves still house one or more sets of “Chladni plates.” We present a brief history of modal analysis of vibrating structures and describe apparatus used by various teachers and researchers, past and present.
The Harvey Fletcher years at Brigham Young University.
Authors: Gee Kent L. , Strong William J. , Sommerfeldt Scott D.
Published: October 2009

Following his long and illustrious career at Bell Laboratories, Harvey Fletcher retired to Provo, UT and continued his career at Brigham Young University. Building on his research at Bell Labs, Fletcher designed and constructed a large anechoic chamber at BYU and also pursued numerous research projects with students at the university. These projects often required the development of research equipment that was very innovative in its time, much of which is still in existence today. This paper will summarize some of the research carried out during those years, and the measurement equipment and apparatus developed by Fletcher and his students to obtain the desired measurements.
Two-dimensional display of nonlinearity parameter B/A automatically measured with focused Gaussian beam.
Authors: Saito Shigemi , Kim Jung-Ho
Published: October 2009

A liquid-like sample to fill the 1-mm gap between an acoustic window of polystyrene plate and a tungsten reflector is set in water within the focal region of an 18.6-MHz focused Gaussian beam, whose width is 0.2 mm in the sample. The sound speed is measured with the time of flight. The density is obtained from the reflection coefficient at the interface between the polystyrene and sample. Emanating a dual frequency wave of fundamental and its double frequencies, two attenuation coefficients are estimated from the amplitudes at those frequencies in the sound transmitted through the sample. The magnitude of velocity dispersion is also derived from the relative phase difference of two frequency components. Based on the finite amplitude method, the nonlinearity parameter B/A is finally determined with the second harmonic amplitude. All the process including the setting of the reflector surface on the focal plane is automatically conducted in 5 s with LABVIEW programs. Scanning the beam over a 3×3-mm2 area, the measured B/A is displayed in a two-dimensional image of 256 segments.
Stress dependent diffuse ultrasonic backscatter coefficient for polycrystalline media.
Authors: Turner Joseph A. , Ghoshal Goutam
Published: October 2009

The diffuse ultrasonic backscatter coefficient (BSC) is a fundamental quantity associated with scattering in heterogeneous media. During a pulse-echo scattering experiment, the energy that scatters back to the source transducer is proportional to the BSC. Theoretical models of the BSC can often be derived from first principles if the heterogeneities can be appropriately modeled. In this case, the statistical properties of the microstructure can be determined in closed form. Polycrystalline materials, such as steel or aluminum, are one class of materials for which the BSC can be determined, typically by assuming that the material is in a stress free state. In this presentation, this fundamental approach is extended to the case in which an applied stress is added to the material. The nonlinear behavior of the grains is included in the analysis such that dependence of the BSC on stress is derived. The stress dependent BSC for different scattering modes relevant to specific experimental configurations is also discussed. Numerical results are presented for materials of common interest and for which single crystal third-order elastic data are available. [Work supported by US FRA.]
Sensitivity analysis of measurements associated with nonlinear material constants for piezoelectric crystals.
Authors: Zhang Haifeng , Turner Joseph A.
Published: October 2009

A robust understanding of nonlinear effects associated with langasite single crystals (electroelastic effect, force-frequency effect, acoustoelastic effect, etc.) is critical for the design of numerous acoustic devices. These nonlinear effects are closely related to the nonlinear material constants. It is common for these constants to be determined through measurements of force-frequency and electroelastic effects or through measurements of ultrasound wave speed changes with respect to external loads/electrical fields. However, due to the complexity of the anisotropy of langasite single crystals, a careful selection of samples with an optimal design is critical for the accurate measurements of these material constants. In this presentation, the first quantitative analysis for the sensitivity of these measurements with respect to extraction of the nonlinear material constants is discussed as applied to langasite single crystals. The sensitivity of each of the third-order elastic and piezoelectric constants to the force-frequency, electroelastic, and acoustoelastic effects of langasite resonators is analyzed. The analysis provides information with respect to the measurement uncertainty for each constant given a set of resonator cuts such that an optimal set can be chosen. These results provide an important reference for the determination of nonlinear material constants of langasite and other piezoelectric materials.