bluuebunny/crossref_metadata_2025 huggingface dataset:
Scripps classroom connection NSF Graduate STEM Fellows in K-12 education program
Authors: Moskovitz Brianne , Staudigel Hubert , Peach Cheryl
Published: October 2011

The scripps classroom connection (SCC) graduate STEM fellows in K-12 Education is a 5-yr program funded through NSF's Division of Graduate Education. The goal of this program is to prepare graduate students for professional and scientific careers for the 21st century. In addition to improving communication and presentation skills for the graduate fellows, the program brings authentic science into middle and high school classrooms of the San Diego Unified School District and creates an enduring set of lesson plans and activities based on the interdisciplinary science conducted at Scripps. One such lesson involves the introduction to ocean acoustics. An activity to accompany this lesson shows the difference in comparison of how sound travels in air and how sound travels in water. Students are able to understand that acoustic waves travel differently in different media.
Languages and conceptualization of soundscapes: A cross-linguistic analysis
Authors: Cance Caroline , Guastavino Catherine , Dubois Danièle
Published: October 2011

In the past decade, soundscape research has emerged accounting for acoustic phenomena as they are perceived and assessed by humans. In this view, concepts and methodologies from social sciences and humanities are needed to identify the diversity of conceptualizations across time, space, and languages. Specifically, our approach relies on linguistics and psychology in analyzing how people describe their sensory experience (what is being said and how it is being said), in order to identify different conceptualizations conveyed in their discourse. We first investigate the linguistic resources available in different languages with a cross-linguistic survey of free-format verbal descriptions of acoustic phenomena in European languages (e.g., French, English, Dutch, Spanish), extending the pilot investigation by Dubois and Guastavino (2008). Then, coupling this linguistic analysis with cognitive theories on categorization, we can infer a diversity of conceptualizations for the same acoustic phenomena. This approach further allows us to overcome some limitations of current survey design: the use of closed-ended questions confining responses to categories pre-defined by the experimenter, and basic translations not taking into consideration semantic languages specificities. Our results provide a theoretical grounding and methodological guidelines for designing questionnaires for cross-cultural evaluation of soundscapes.
Understanding soundscape as a specific environmental experience: Highlighting the importance of context relevance
Authors: Aspuru Itziar
Published: October 2011

A proposed general conceptual model about environmental experience is presented to guide the soundscape studies. This proposal is the output of a review of the literature on soundscape and our experience regarding psychosocial studies in Tecnalia focuses on the relationship between environment and persons or communities. The general model has been structured around five main elements: person (community), place, activity, previous interaction between person and place, and environmental experience. The environmental experience is a holistic experience within that soundscape and is linked to other perceptions, such as landscape, odour, etc. The relevant factors and variables of each main element have been identified to help us to explain human and social holistic experience in relation to place, in general, and soundscape (perception) in particular. The main objective of this paper is to present this model and to discuss it with interested colleagues.
The use of musical composition and spatial analysis to document and design soundscapes
Authors: Fisher Joshua C
Published: October 2011

A series of studies were conducted that used augmented environmental noise analysis techniques. Impulse response analysis and digital processing techniques were applied to both previously recorded sound samples and binaural recordings found on a target site. To provide a representation of the character of a given space, recordings of individual sounds on the site were used to construct digitally composed auralizations of the objects and spaces that were representative of the target space over time. By treating the spatial environment and the individual sounds as separate elements, this technique allowed existing soundscape studies to be used as base models for new soundscapes. This technique was implemented in a number of studies in various natural and manmade locations, all of which demonstrated that sound could be used as part of an integrated design process that allows the designer to treat sound as a material rather than as an unwanted substance (noise).
Pursuing cooperative solutions to noise management issues arising in U. S. National Parks
Authors: Fristrup Kurt M.
Published: October 2011

An emerging paradigm in wildlife conservation holds that ecological knowledge is but one of several dimensions that must be addressed to realize successful outcomes. Human factors—history, culture, economics, and mechanisms for decision and implementation—must be taken into account to devise effective solutions. Addressing these factors demands systematic identification and pursuit of partnerships to synthesize a social tool for conservation. In soundscape management, there has been substantial discussion of metrics for measuring noise exposure and how these measures of noise exposure translate into functional consequences for humans. These challenges, which are substantial, may be the least formidable obstacles to constructive change. The recent history of noise management efforts in the National Park Service illustrate the necessity of cultivating partnerships in many pursuits: education and outreach, research and evaluation, informing policy decisions, and implementation of management plans.
Long-term fish monitoring in the Southern California Bight
Authors: Širović Ana , Demer David A. , Wiggins Sean M. , Hildebrand John A.
Published: October 2011

While over 100 fish families produce sounds during behaviors like spawning, aggression, and feeding, passive-acoustic sampling is not used commonly for long-term fish population monitoring. Fish sounds consist mostly of low-frequency pulses of variable duration, number, and repetition rate, but it is often difficult to identify their sources to species. For example, underwater sounds from marine life have been studied in the Southern California Bight (SCB) for over 60 years, but because the sound producing fishes are difficult to locate and identify visually, their sound production remains poorly understood. The spatial and temporal distributions of the likely fish sounds recorded in SCB were analyzed, but the species producing those sounds are generally unknown. Where the species are known, more information is needed on the seasonal and interannual variations of their sound production if the passive-acoustic records are to be used to estimate their abundances and distributions. We show that sound characteristics and diel sound production patterns for some species, like bocaccio (Sebastes paucispinis), have not changed for over four decades. More directed studies are needed on the behavioral context of fish sound production in SCB to facilitate the use of passive-acoustic monitoring for long-term studies of fish population dynamics.
Automatic detection of vocalizations of the frog Diasporus hylaeformis in audio recordings
Authors: Camacho Arturo , García-Rodríguez Adrián , Bolaños Federico
Published: October 2011

A method for the automatic detection of calls of the frog Diasporus hylaeformis (Eleutherodactylidae) in audio recordings is proposed. The method uses the loudness, timber, and pitch of the vocalizations to identify the calls of the most prevalent individual in a recording. The first step consists in calculating the loudness of the signal to recognize the sections where the focal individual's vocalizations are. The second step consists in using the timber of the signal to recognize vocalizations. Finally, we use two principles we observed in the sounds produced by this species to discriminate between the calls of the most prevalent individual and other calls: individuals tend to vocalize using an almost constant pitch and different individuals use different pitches. Results show that the method is resistant to background noise (including calls of individuals of the same species), microphone-manipulation-induced noise, and human voice, and also that it adapts well to variations in the microphone level produced during the recording.
Localized activation and cellular effects of ultrasound triggered drug delivery vehicles with encapsulated microbubbles
Authors: Ibsen Stuart , Benchimol Michael , Simberg Dmitri , Schutt Carolyn , Steiner Jason , Esener Sadik
Published: October 2011

The harmful side effects of chemotherapy originate from indiscriminate exposure of healthy tissue to the drugs. The goal of targeted drug delivery is to reduce these side effects by encapsulating concentrated drug in a vehicle which releases it only in the tumor region. Low intensity focused ultrasound can be used as a trigger to specifically activate these vehicles by highlighting only tumor tissue, creating a stark differentiation with healthy tissue. A new injectable drug delivery vehicle has been developed with a stabilized nested lipid shell geometry that encapsulates a high capacity chemotherapy payload, and a stabilized microbubble into one structure. Ultrasound affects the microbubble only in the small focal volume, creating a localized shockwave which ruptures the vehicle's outer membrane triggering pinpoint release in tissue phantoms. These shockwaves, and their interactions with the delivery vehicle membranes and live cells, have been documented for the first time using a custom system which combines high-speed videography and fluorescent microscopy with focused ultrasound. Vehicles which do not pass through the tumor will be excreted through normal processes. This externally-activated scheme could lead to truly tumor-specific drug delivery. [NCI Grant No. 5U54CA119335-05, and UCSD Cancer Center Specialized Support Grant No. P30 CA23100 supported this work.]
Stepped-plate transducer as an energy transmitter
Authors: Hwang Yonghwan , Je Yub , Lee SungQ , Hwang Gunn , Moon Wonkyu
Published: October 2011

Power transmission through acoustic energy may be useful in such cases as supplying power to wireless small sensors. In the case, the radiation and reception power efficiency is important. Even in ultrasonic frequency bands, the power efficiency of most acoustic radiators in air is not high enough. The stepped-plate ultrasonic transducers, introduced by Gallego-Juarez etal. [Ultrasonics 16, 267–271(1978)], may be a good candidate for the radiator for this purpose because it can effectively generate highly directive, large-amplitude, ultrasonic sounds in air. The transducer consists of langevin transducer that causes wave generation, mechanical amplifier, and stepped radiation plate. Although it is reported to achieve 80% of power efficiency, it is not reported how to achieve maximum power efficiency. For design of large-amplitude, high-efficiency stepped-plate transducer, the design of not only individual parts but also system integration of entire transducer is important. In this research, we developed an analytical model for the whole transducer by combining continuum models of each parts and found proper design parameters for the radiation power and the power transmitting efficiencies. Then, we seek the optimal design for maximizing power efficiency through parametric analyses, and the results are confirmed through finite element method analysis. [Work supported by ETRI (South Korea).]
Unidirectional multimode piezoelectric spherical transducers
Authors: Brown David A. , Aronov Boris , Bachand Corey
Published: October 2011

Analytical and experimental results are presented for unidirectional broadband multimode piezoelectric acoustic transducers utilizing axisymmetric vibrations of spherical transducers. The analysis covers the acoustic radiation and reception by including the acoustic impedance's and diffraction coefficients for transducers with conformal baffles. The energy method is used to obtain equivalent parameters for a multi-contour electromechanical circuit representation of the transducer and to calculate performance. Experimental data obtained are in good agreement with analytical results.
Compact cylindrical transducer arrays for directional communications and navigation
Authors: Brown David , Aronov Boris
Published: October 2011

Designs and experimental results are presented for compact self-baffled cylindrical arrays comprising piezoelectric transducers suitable for telemetry stations and small vehicle directional communications or navigation. Designs with cylindrical transducers, rod/bar transducers, and tonpilz elements are compared with single transducers using turnable baffles to achieve unidirectional beams that may be steered in azimuthal plane.
Estimating the clarinet mouthpiece reflection from measurement and the instrument's produced sound
Authors: Smyth Tamara , Abel Jonathan
Published: October 2011

In this work, a method is presented for estimating the reflection off the clarinet mouthpiece, using a priori measurement of the bell, and post processing of the instrument's produced sound. A previously introduced measurement technique is used to obtain measurement of clarinet bell and transmission filters. In addition to these elements, however, the round-trip propagation loss in the clarinet bore and bell also includes wall loss and mouthpiece reflection. Though the former is accurately modeled theoretically, assuming the clarinet bell is close to cylindrical, the mouthpiece is more difficult to measure, both because of a supposed oscillating reed, and because the required placement of a measurement device would obstruct the mouthpiece's characteristic reflection. The lumped round-trip loss filter in the bore is estimated from the clarinet signal by first considering the signal's periodic structure. After taking the signal's autocorrelation, which preserves its periodicity and naturally provides the beginning of the period, the round-trip filter is iteratively estimated by constructing an optimization function from the first and second phases of the autocorrelation sequence. Once the round-trip loss is estimated, the mouthpiece reflection may be extracted by removing the effect of the other known comprising filter elements.
Inverse problem in sound synthesis and musical creation using mass-interaction networks
Authors: Villeneuve Jérôme , Cadoz Claude
Published: October 2011

Sound synthesis with mass-interaction physical modeling networks is known as a general paradigm capable of being the central part of complete software environments for both sound synthesis and musical creation. GENESIS 3, resting on the CORDIS-ANIMA formalism and developed by ACROE/ICA Laboratory, is the first environment of this kind. Using it, the artist may be facing an inherent problematic of every creation process: how to use a given tool in order to obtain an expected result. In our context, the question would be: “Considering a sound, which physical model could produce it?” Our work aims at formalizing this inverse problem and therefore at helping the user through his creative process. Therefore, we will consider how he could describe a sound (entry of the inverse problem), how to define a generator model based on mass-interaction physical networks and each one of its subcomponents (formal solution of the inverse problem), and, obviously, how to compute this solution considering an entry (resolution of the inverse problem). In this paper, we will develop each one of those three points and present the first algorithmic resolutions already implemented and used within GENESIS 3.
Real-time finite-difference string-bow interaction floating point gate array (FPGA) model coupled to a violin body
Authors: Florian Pfeifle , Rolf Bader
Published: October 2011

A string/bow interaction model as proposed by Bader, R.: Whole geometry Finite-Difference modelling of the violin. In: Proceedings of the Forum Acusticum 2005, 629-634, 2005 and a 3D violin geometry with top plate, back plate, and enclosed air was implemented in real-time using an FPGA hardware implementation. The bow/string interaction uses conditions for gluing and tear-off the string to/from the bow, where gluing happens with relative string/bow velocity below a threshold and tear-off with either the string curvature or the string tension at the bow point too high modelling the cases appearing with normal Helmholtz motion or the occurrence of subharmonics, respectively. The model can be played changing bow pressure and velocity, bow point on the string, and string length. The resulting sounds are highly realistic showing gradual timbre changes from normal Helmholtz motion, double slit motion, weakening of the fundamental, or noise with very low pressures. It appears that these interaction conditions can realistically be used to model the bow/string interaction.
Synthesizing classic recording microphones characteristics using a spherical microphone array
Authors: Peters Nils , Schmeder Andrew W.
Published: October 2011

Using spherical microphone arrays to form directed beams is becoming an important technology in sound field analysis, teleconferencing, and surveillance systems. Moreover, in scenarios for capturing musical content, the recording and post-production process could be simplified through flexible beamforming technology. Often, audio engineers favor the use of conventional recording microphones over spherical microphone arrays which might be due to the engineer's preference for distinct spatial and timbral characteristics of different microphone types and brands. We present an approach to create beamforming pattern using a 144 channel spherical microphone array, which aims to match the distinct spatial and timbral characteristics of classic microphones. For this, we first measured the spatial and timbral characteristics of several classic microphones types as well as the characteristics of our spherical microphone array in an anechoic chamber. Using a regularized least-square approach, these data were then used for computing the filters for the spherical microphone array that forms the desired beams. We show the results of several microphone-beam simulations and compare them with the impulse responses of the original classic microphones. Advantages and limitations of our approach will be discussed.
FireFader: A single degree-of-freedom force-feedback device for multimodal interaction with physical models
Authors: Berdahl Edgar J.
Published: October 2011

The design of a relatively inexpensive force-feedback device known as the FireFader is presented. It is controlled using physical models to provide multimodal force, auditory, and visual feedback in real time, and it is based upon a linear potentiometer fader coupled to a DC motor, also known as a “motorized fader”. Lamps are connected electrically in parallel with the motor in order to visually communicate the strength of the force. The device is linked by a serial USB interface to a general-purpose computer, which employs a physical model to calculate the motor force as a function of the fader position. The USB interface causes delay of the control signal, but it facilitates easier programming and less expensive control. Furthermore, additional sensed parameters can help provide the illusion of more than a single degree-of-freedom (DOF) feedback, via modulation of the physical model parameters. For estimation of the downward force applied by the performer on the fader, a pair of force sensors can be sandwiched in between the motorized fader and the housing. In conclusion, we hypothesize that by providing multimodal feedback in real time, the FireFader may help promote the expressivity of new media interactions.
Equivalent circuit modeling and vibrometry analysis of the Udu Utar Nigerian drum
Authors: Hilton C. Beau , Anderson Brian E. , Jones Hillary
Published: October 2011

The udu drum is both an aerophone and an idiophone played with both of the musician's hands. It originates from Nigeria where it began as a functional water pot made out of fired clay. At some point, a side hole was cut into the pot and it became a musical instrument, traditionally played by women, which had an important role in religious ceremonies. The udu is capable of producing deep tones that result from acoustic resonances similar to those of Helmholtz resonators, though with a second hole. It also may produce higher pitch sounds that result from the musician tapping the surface of the udu. This paper will discuss one-dimensional equivalent circuit modeling of the acoustic resonances of the udu. A comparison of the resonance frequencies in the equivalent circuit modeling to measured resonance frequencies will be given. Additionally, an analysis of the structural modes of the udu as measured by a scanning laser vibrometer will be given, along with some insights into the sound produced by striking the drum at different locations. This information may be used by udu designers to better tune these instruments.
Further development of a launch pad noise prediction model
Authors: Plotkin Kenneth J. , Vu Bruce T.
Published: October 2011

A model, PAD, has been developed for prediction of noise in the vicinity of launch vehicles, with specific application to the mobile launcher and tower for the Ares I launch vehicle. It follows the basic principles of a traditional NASA model (NASA SP-8072, 1971), with updated source components, including impingement and water suppression. The recent 5% scale Ares scale model acoustic test (ASMAT) exhibited sources not properly represented in PAD. These sources are noise increase associated with flat plate deflection of a supersonic plume, and generation of noise from impingement of the plume on an edge such as a launch mount or the edge of the exhaust hole in the launcher deck. New sources, based on ASMAT measurements, have been added to PAD to account for these effects. Treatment of the launch deck has also been generalized to permit full three dimensional launcher configurations, rather than a simple two dimensional arrangement with the tower over the flame trench. The prediction domain has also been expanded to include exhaust plume noise levels on the underside of the deck. (Work supported by the National Aeronautics and Space Administration.)
A review of large solid rocket motor free field acoustics
Authors: Pilkey Debbie , Kenny R. Jeremy
Published: October 2011

Approximately twice a year, ATK Aerospace Systems has static fired an assembled reusable solid rocket motor (RSRM) in a horizontal configuration at its test facility in Utah. The firings took place on elevated terrain with the nozzle exit plume mostly undeflected and the landscape allowing placement of microphones within direct line of sight to the exhaust plume. NASA and ATK underwent a significant effort over several years to collect acoustic data in the free field and on the motor itself during RSRM static test firings. These data were used to characterize the acoustic field and to update the prediction methodologies in the monograph NASA SP-8072 “Acoustic Loads Generated by the Propulsion System.” This work represents a review of the free field acoustics generated during large solid rocket motor firings and may be the only repeatable free field acoustic experiment on motors like these.
Energy-based acoustic measurement system for rocket noise
Authors: James Michael M. , Gee Kent L.
Published: October 2011

Accurate estimates of the vibroacoustic loading placed on space vehicles and payloads during launch require knowledge of rocket noise source properties and near-field acoustic energy flow characteristics. Without these data, structures may not be designed to handle the correct vibroacoustic loads, which can result in either an over-built, excessively massive structure or an under-designed vibration mitigation system that could result in damage to payloads. These measurements are difficult to perform because of the extreme nature of the acoustic and temperature environments near the rocket plume as well as the large physical size of the rocket noise source. With these design constraints in mind, a field-deployable data acquisition system and energy-based measurement probe have been developed to measure the magnitude, directivity, and spectral content of the rocket source. Initial measurements with various prototypes were conducted during a static test fire at ATK Space Systems Test Services in Promontory, Utah with limited results presented here. [Work sponsored by NASA John C. Stennis Space Center.]
Low-frequency calibration of a multidimensional acoustic intensity probe for application to rocket noise
Authors: Giraud Jarom H. , Gee Kent L. , Sommerfeldt Scott D. , Taylor R. Troy , Blotter Jonathan D.
Published: October 2011

Measurements of acoustic vector quantities in the near field of a solid-fuel rocket motor are useful for enhancing prediction models related to rocket noise. However, the probes used to measure these quantities traditionally have low-frequency bandwidth limitations (e.g., below 45 Hz) thereby excluding the lowest, and in some cases, the loudest frequencies generated by large rocket motors. At these low frequencies, the phase and magnitude mismatch between microphones become greater and the acoustic phase separation between any two microphones becomes smaller, resulting in more error in estimating the pressure gradient between microphones. To investigate the low-frequency response of an acoustic intensity probe, a turntable is used to rotate a four-microphone probe with variable microphone spacing in a low-frequency noise field and an experimental assessment of the bandwidth is given for both magnitude and directional response. Also discussed is the effectiveness of a microphone interchange calibration technique to remove amplitude and phase mismatch and increase the usable bandwidth of the probe.
Sliding dynamic studies by use of elastography
Authors: Latour Soumaya , Catheline Stefan , Campillo Michel , Renard Francois , Voisin Christophe , Larose Eric , Gallot Thomas
Published: October 2011

To get an insight into the processes underlying dynamic friction that plays an important role in seismic sources, we developed a sliding dynamic experiment coupled to elastography imaging. This experimental setup permits to observe simultaneously the frictional interface and the waves emitted in the bulk during slipping. We use soft solids made of hydro-organic gel of PVA, in contact with either glass or sandpaper. The huge interest of such soft solids is that elastography allows to observe in real time the rupture nucleation and propagation, as well as shear waves themselves inside the medium. We investigate the friction in two different cases. In the case of friction on sand paper, links are formed between the gel and the sand paper by local pinning. The breaking of these links emits a characteristic wave pattern, and their occurrence is related to the local sliding velocity. In a very different way, when the gel slide on a glass surface, with an interlayer of sand grains, the slip occurs as successive rupture events, with a rupture front crossing the whole surface. We can study then the rupture velocity, and in the cases of ruptures faster than the shear wave velocity, we observe a Mach cone of shear waves.
An investigation into the interaction of a grazing angle broadband spherical audio signal with the dynamically rough air–water interface of shallow flows in rivers and channels
Authors: Nichols Andrew , Horoshenkov Kirill V. , Tait Simon J. , Attenborough Keith
Published: October 2011

Laboratory measurements were made of a broadband audio signal transmitted and received at grazing angles over a range of shallow water flow regimes. Synchronous measurements of local surface fluctuation were taken using a thin-wire wave gauge positioned at the point of specular reflection. The first and second statistical moments of the acoustic intensity at the receiver are shown to be directly related to the second statistical moment of the water surface fluctuations. It was hypothesized that this relationship was due to the path-length of the dominant signal fluctuating in direct relation to the interface fluctuations at the specular reflection point. This hypothesis is corroborated by analysis of the second statistical moment of the “time-of-flight” of the surface-reflected signal, and by direct analysis of the instantaneous water surface position.
Performance of thermoacoustic device and its thermal contact to a source
Authors: Rodriguez Ivan , Symko Orest G. , Flitcroft Myra
Published: October 2011

An important application of a thermoacoustic prime mover is in the conversion of heat to electricity when coupled to a sound to electricity converter. In order to achieve maximum sound output, the thermal coupling of the heat source is critical. This was studied here by using (i) a constant heat flow heat source and (ii) a constant temperature difference heat source. As in an electric system where the higher efficiency of power delivery is for a constant voltage source, maximum heat is delivered to the acoustic device from a constant temperature difference heat source. This was investigated on a 1.94 kHz thermoacoustic engine coupled to an acoustic cavity. A shutter located inside the cavity made it possible to have sound on and sound off. In the constant heat flow approach, the shutter technique gave a direct value and measure of heat which was converted to sound. The constant temperature difference approach provided the most heat input for maximum sound output. The temperature profile of cold heat exchanger, hot heat exchanger, and stack was determined by thermocouples.
Monotic versus diotic thresholds in an amplitude modulation and quasi-frequency modulation discrimination task
Authors: Borucki Ewa , Shim Allison I. , Berg Bruce G.
Published: October 2011

This study investigated monaural and binaural differences in a task traditionally used to investigate the bandwidths of phase sensitivity. Subjects discriminated amplitude modulated (AM) tones and quasi-frequency modulated (QFM) tones presented diotically. An adaptive threshold procedure was used to estimate modulation depth needed to make the discrimination as a function modulation frequency for a 2000-Hz carrier. Threshold functions were often nonmonotonic, with nonmonotonicities observed at higher-modulation frequencies (above 600 Hz). This is likely due to the effects of cubic difference tones (CDTs) creating spectral cues, yielding lower thresholds. Subjects then completed the task at higher modulation frequencies monotically, demonstrating differences between monotic and diotic thresholds. Within subject thresholds also differed between left ear and right ear presentations. Some subjects yield nonmonotonic thresholds in the monotic condition, even when diotic thresholds were monotonic. For these subjects, it is likely that the CDT interaction is not consistent between the two ears, rendering them an unusable cue when stimuli are presented diotically. Distortion product otoacoustic emissions (DPOAEs) were measured and support the hypothesis that nonmonotonicities found are the effect of a CDT interacting with the low tone of the stimulus.
Converging evidence from behavior and electroencephalography for differences in the storage of streams versus individual sound objects
Authors: Varghese Lenny A. , Best Virginia , Shinn-Cunningham Barbara G
Published: October 2011

Previous psychophysical experiments from our lab have suggested a difference in the way perceptual sound streams and discrete sound events are stored in short-term memory. We explored differences in brain activity during memory retention of these two kinds of sequences using EEG. Listeners heard a target sequence composed either entirely of short pitched tones (forming a stream) or natural sounds (e.g., a horn or a scream, which are perceptually disconnected), while scalp activity was recorded using EEG. After a 2 s retention period, listeners were required to detect a change in the ordering of a probe sequence (same/different). For a given sequence length, performance for pitched tone sequences was consistently higher than for natural sound sequences, suggesting that memory retention of an auditory stream requires less cognitive effort than retention of a sequence of perceptually disconnected sounds. Retention period alpha (8–12 Hz) oscillatory activity generally increased from pre-target levels in parietal and occipital electrodes for both types of sound sequences, with a trend toward more widespread increases for natural sounds. These results may indicate that alpha activity is related to the amount of cognitive effort required to maintain sound sequences in short-term memory. [Work supported by NSSEFF grant to BGS-C.]
The response to R ½ T. Can forensic acoustics play a leading rôle in a new wave of adoption of the likelihood-ratio framework?
Authors: Morrison Geoffrey Stewart
Published: October 2011

In 2010, the England and Wales Court of Appeals ruled in R ν T that the likelihood-ratio framework should not be used for the evaluation of evidence except “where there is a firm statistical base.” It was not favorable to the use of likelihood ratios even if a firm statistical base does exist. It was, however, willing to accept evidence without a firm statistical base, but on the condition that likelihood ratios are not used. In response, 31 leading forensic scientists published a statement asserting that the likelihood-ratio framework is the logically correct way to evaluate evidence (as a logical framework it is not itself dependent on data or statistical models). This statement has been endorsed by the board of the European Network of Forensic Science Institutes, representing 58 laboratories in 33 countries. Forensic scientists have argued that the ruling is based on misunderstandings of both the likelihood-ratio framework and statistics. The presenter proposes that the magnitude of the response to R ν T potentially heralds a new wave of adoption of the likelihood-ratio framework by forensic scientists and by the courts (the first wave was DNA in the 1990s) and that forensic acoustics can potentially play a leading rôle.
Nasal spectra for forensic voice comparison
Authors: Enzinger Ewald , Zhang Cuiling
Published: October 2011

For features to be effective in forensic voice comparison, they must have relatively low within-speaker variability and relatively high between-speaker variability. An understudied source of features, which potentially meets these criteria is the acoustic spectrum of nasals. Nasals spectra contain poles and zeros dependent upon nasal cavities. The latter are complex static structures which vary from person to person. Theoretically, nasal spectra may therefore have low within-speaker and high between-speaker variabilities. This study evaluates different methods for extracting spectral features (e.g., pole-zero models, all-pole models, and cepstra) and using them as part of a likelihood-ratio forensic-voice-comparison system. The validity and reliability of each system is empirically evaluated using /m/ and /n/ token extracted from a database of voice recordings of 60 female speakers of Chinese.
The Canadian shift in Ontario: Transmission and diffusion
Authors: Roeder Rebecca V.
Published: October 2011

The Canadian Shift, a sound change in progress that is affecting the front lax vowels of Canadian English, was initially characterized as a chain shift. However, recent studies have observed a different pattern of movement over apparent time, requiring an alternative theoretical model to explain the change. Relying on instrumental analysis of data from nearly 100 speakers across five Ontario cities and towns, this paper provides additional observations of parallel shifting across apparent time in these vowels and adopts vowel dispersion theory as a theoretical framework for positing phonetic movement toward a system that is balanced both phonetically and phonologically. This phonetically-based model has primarily been used to explain the relationship between phonological inventories and acoustic space, but the generalizations and principles that are emerging through such research are also useful in the interpretation of observations regarding sound change in progress. Findings also indicate that the geographical progression of the shift corresponds with a cascade or gravity model of diffusion.
Voice onset time production in Singapore English
Authors: Liu Priscilla Z.
Published: October 2011

This current study investigates the effects of linguistic accommodation through the production of voice onset time (VOT). Six Singaporeans were recorded in three separate conversations that differed by interlocutors: 1) another Singaporean, the researcher, and a non-Singaporean. The two Singapore English dialects, Standard Singapore English (SSE), and Singlish, are investigated. SSE is influenced by British English while Singlish draws from a myriad of languages, “mother tongues” that are spoken in Singapore: Mandarin Chinese, Hokkien, Tamil, and Malay. Thus, Singaporeans were expected to shift production of VOT as motivated by linguistic accommodation to their interlocutors. Previous research indicates that VOT is a valuable acoustic demarcation of phonetic and phonological boundaries. Thus, speakers were found to significantly shift their production of VOT for /p t k/ towards phonetic categories of British English or Malay and Tamil dependent on their audience. (Though the trends for /b d g/ were not significant, the numerical data also shift in the same direction.) Lastly, the paper discusses the implications of these results, that although SSE and Singlish are not entirely discrete and both exist as heavily used dialects of English in Singapore, speakers manipulate VOT in order to accommodate their listeners.
Acoustic contrastivity in conversational and loud speech
Authors: Kim Yunjung
Published: October 2011

Despite frequent clinical observations of improved speech intelligibility following high vocal intensity training in speakers with dysarthria, the mechanism by which loud speech results in increased speech intelligibility is little understood. Prior research has reported conflicting acoustic results of articulatory modifications in loud speech conditions such as changes in vowel durations, acoustic vowel space, and F2 transition duration/extent. More interestingly, the impact of an overall increase in amplitude of speech signals on perceptual judgment of speech intelligibility is unclear, especially when the entire speech signal is amplified as compared to the amplification of selected phonetic events (see Kim and Kuo, in press). This presentation focuses on the change of relative contrastivity within utterances that were produced at both conversational and loud levels to better understand the underlying mechanism of enhanced speech intelligibility secondary to greater vocal intensity. In this presentation, data on the ratio of vowel durations (long versus short), formant structures of vowels (tense versus lax), as well as the ratio of syllable intensity (stressed vs unstressed) will be compared between conversational and loud speech conditions produced by young adult speakers.
Visual speech influences on interactive speech alignment
Authors: Dias James W. , Cook Therasa , Rosenblum Lawrence D.
Published: October 2011

Speech alignment describes the unconscious tendency of humans to produce speech that shares the acoustical characteristics of a perceived speech signal. Participants have been found to align more when interacting in full view of their partner than when conversing only through sound [J. W. Dias and L. D. Rosenblum, J. Acoust. Soc. Am. 128, 2458 (2010)]. However, this previous study did not address what specific visual information enhances speech alignment. The present study evaluates whether being able to see visual speech gestures enhances alignment in a conversational setting. Pairs of participants performed an interactive search task, for which they were required to utter nine key words multiple times. Participants performed the task, while interacting face-to-face, or with visibility of the mouth and throat occluded using a small sound-permeable screen. Participants' utterances of the key words were recorded before, during, and after the interaction. Alignment was evaluated by naïve raters in an AXB matching task. In a second experiment, participants performed the task in a background of talker-babble noise. Preliminary results indicate that alignment increases with visibility of the mouth. The findings are consistent with evidence that alignment occurs to amodal, gestural properties of perceived speech.
Liquids as syllable peaks: Preconsonantal laterals in closed syllables of American English
Authors: Nelson Onna A.
Published: October 2011

Liquids occur in all syllable positions in English and may behave as syllable peaks or nuclei (Proctor, 2009). Previous work has examined syllabic liquids in open syllables like little and doctor, in the onset of closed syllables like prayed and played (Price, 1980) and has established that rhotics are syllabic in certain closed syllables like bird, church, and learn. However, little work has investigated whether laterals can serve as syllable peaks in preconsonantal position. This study examines potential syllabic liquids in closed and open syllables in the Santa Barbara Corpus of Spoken American English (Du Bois etal., 2000, 2003, 2004, 2005), focusing on CVlC syllables, such as bulk, filled, and help, which are structurally similar to the aforementioned contexts containing syllabic rhotics. Vowel and lateral duration and intensity are measured to determine whether these laterals display properties associated with syllabicity (Price, 1980). Additionally, the first and second formants of the vowel and lateral are measured at 10 ms intervals to examine the vowel-like behavior of the liquids (Gick, 2002). Further influencing factors are considered, including morphology, surrounding vowel quality, place and manner of surrounding consonants, intonation, and other prosodic elements to determine the environments in which lateral syllabicity occurs.
Vowel undershoot in production of English tense and lax vowels by Mandarin and American speakers
Authors: Yang Chung-Lin
Published: October 2011

Vowel undershoot (Lindblom, 1963), an effect where the articulatory gesture fails to reach the target due to the following contrary gesture (de Jong, 2004), is found to be particularly prominent (lowered F1 and shortened duration) in polysyllables (Lindblom, 1968; Moon and Lindblom, 1989). The current study investigates Mandarin and American speakers' production of English tense-lax vowels /i/-/I/ and /eI/-/ε/, and examines undershoot in monosyllabic and disyllabic words. Three Mandarin and three American speakers were recorded. Fifteen target vowels were embedded in a voiced stop-V-voiceless stop context. All disyllabic words were first-syllable stressed. Carrier sentences were of variable length to create a natural-speech-like context. F1, F2, vowel duration and utterance duration were measured. The results show that Americans did show a significant distinction between /i/-/I/ but tended to merge the formants of /eI/-/ε/ in disyllabic words, which was partly due to the coarticulation with the following syllable. They also demonstrated undershoot effect in /eI/-/ε/ but not much in /i/-/I/. Mandarin speakers, however, could not make a significant tense-lax distinction, and showed formant undershoot in disyllabic words, especially tense vowels. One possible account for this effect is the influence from L1. The issue of Mandarin vowel inventory is discussed.
Voice quality and pitch contrast in non-native Korean
Authors: Chang Seung-Eun
Published: October 2011

In this study, I compare the effects of linguistic experience on voice quality (H1-H2) and fundamental frequency (f0) in Korean stops among native and non-native Korean speakers. Native speakers of Chinese, English, Korean, and Spanish produced Korean words in a /CVC/ context, and H1-H2 and f0 of the initial stops in each set of materials were measured. Korean and Chinese speakers showed creakiness (smaller H1-H2) for Korean tense stops and breathiness (larger H1-H2) for lenis and aspirated stops, whereas English and Spanish speakers showed relatively larger H1-H2 for all stops. For f0 values, Korean and Chinese speakers displayed a lower f0 for lenis, an intermediate f0 for tense, and a higher f0 for aspirated stops. For English speakers, however, lenis and tense stops were merged in the lower f0 region, and aspirated stops showed a higher f0. In Spanish speakers, tense and aspirated stops merged in the higher f0 region, and lenis stops showed a lower f0. These results demonstrate a strong effect of linguistic experience on voice quality and f0: speakers of Chinese were more accurate in replicating Korean stops than were speakers of English or Spanish, languages that lack phonemic voice quality and tone contrasts.
Native English speakers learning German as a second language: Devoicing of word-final voiced stop targets
Authors: Smith Bruce L. , Peterson Elizabeth A.
Published: October 2011

In contrast to German and other languages that devoice underlying word-final, voiced obstruent targets, English has a surface contrast between voiced and voiceless obstruents. The present study investigated the issue of what occurs when native speakers of American English, in an early stage of learning German as a second language, produce word-final voiced and voiceless stop targets in German versus English. The fact that the underlying voicing contrast in German is reflected orthographically (e.g., “Tod” versus “tot”) could make it difficult for native speakers of English to learn to devoice German word-final, voiced targets. The findings indicate that many of the 12 native English learners of German who were studied showed a tendency toward devoicing voiced targets in German relative to their productions of orthographically-similar words in English (e.g., “toad” and “tote”). In general, their partial devoicing in German (relative to their English productions) occurred due to a combination of producing somewhat shorter vowels before voiced consonant targets, reducing glottal pulsing during the closure of voiced consonant targets and/or shortening voiceless consonant closure durations. Subjects who produced more characteristically “voiced” consonants when speaking English (e.g., longer preceding vowel durations, etc.) tended to devoice German final stops to a lesser extent.
Lexical effects in the production of emotional speech
Authors: Kryuchkova Tatiana , Tucker Benjamin V.
Published: October 2011

Emotion in speech production has been shown to correlate well with fundamental frequency (F0), intensity, and duration [B. Zupan etal., J.Commun. Disord., 42, 1–17 (2009)]. Studies in non-emotional speech have shown effects of lexical predictors on speech production (e.g., neighborhood density [B. Munson and N. P. Solomon. J. Speech, Lang. Hear. Res., 47, 1048–1058 (2004)], and lexical frequency [R. H. Baayen etal., in Proceedings of the Annual Meeting of the Chicago Linguistic Society (2007), Vol. 43, pp. 1–29]. In the present study, we investigate the effects of lexical predictors in the production of emotional speech. Two professional male actors recorded 260 isolated words. Three emotional states were analyzed: neutral, anger, and joy. Measures of word frequency, morphological family size, number of synonyms and homophones, and ratings for danger and usefulness [L. Wurm, Psychon. Bull. Rev., 14, 1218–1225 (2007)] were used as statistical predictors in modeling, using linear mixed-effects regression. Following previous literature, both speakers use F0, intensity, and duration to portray emotion. Lexical predictors such as word frequency, morphological family size, and danger ratings were found to significantly predict mean F0, mean intensity, and word duration across emotional types for both speakers.