bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of phonetic orthography on the perception of Mandarin syllables
Authors: Lin Yu-Jung , Yang Chung-Lin , Lin Chien-Jer Charles
Published: November 2013

It has been found that vowels have perceptual advantage over tones (e.g., Ye and Connie, 1999) and that phonetic orthographic information can be activated in speech perception (e.g., Frauenfelder, Segui, and Dijkstra, 1990). In the present study, we used a tone-vowel detection task where Zhuyin (Taiwanese) and Pinyin users (Mainland Chinese) were asked to monitor Mandarin syllables containing [i4] to test how tonal and vowel information are processed in syllable monitoring, and to examine if Zhuyin and Pinyin users’ responses are affected by their phonetic orthographic systems. The results demonstrated that in both groups, vowel-mismatched syllables (e.g., bu4) were rejected faster than tone-mismatched syllables (e.g., bi2). Moreover, the RT of rejecting vowel-mismatched syllables and double-mismatched syllables (e.g., bu2) were similar, indicating that as long as vowel was mismatched, tonal information caused little difference in RT when rejecting the mismatched syllables. This finding was consistent with Ye and Connine (1999). Furthermore, both groups resort to their phonetic orthography in simple syllables (e.g., bi4, zhi4). However, in complex syllables (e.g., biao4), different patterns were observed between the two groups, possibly due to the factors such as how tones are marked in their phonetic orthography or how they learned the orthography.
Perceiving politeness from speech acoustics alone: A cross-linguistic study on Korean and English
Authors: Winter Bodo , Brown Lucien , Idemaru Kaori , Grawunder Sven
Published: November 2013

Politeness is a crucial aspect of everyday speech communication; however, there are to date only few acoustic studies on this topic. Winter and Grawunder (2012) showed that for Korean speakers, politeness is reflected in pitch, intensity, voice quality and speaking rate. Here, we extend this production study by investigating whether Korean and English listeners can perceive the intended politeness of short Korean utterances based on speech acoustics alone. In two experiments with a total of 47 English and 30 Korean listeners, we found that both groups can detect the intended politeness purely based on the phonetic qualities of speech. In one experiment, accuracy was low (Korean: 58%, English: 53%) because speakers heard multiple voices in a randomized fashion, not allowing them to familiarize with any particular voice. In a design that was blocked by speaker voice, accuracy was higher (Korean: 70%, English: 58%), showing that vocal politeness can be used as a cue when the voice is known. This shows that politeness is not only expressed by honorific lexical forms commonly employed in Korean, but also by speech acoustics. It is remarkable that English speakers performed above chance at all, pointing to cross-linguistic regularities in how politeness is expressed vocally.
The role of vowels in determining a male speaker's sexual orientation
Authors: Tracy Erik C.
Published: November 2013

Prior research (Tracy and Satariano, 2011) found that listeners primarily use the vowel in a monosyllabic word to determine the speaker’s sexual orientation. Given this result, if listeners were presented utterances that contained multiple vowels, then the accuracy of their sexual orientation ratings should increase. In Experiment 1, listeners were presented with trisyllabic words (“authentic”). They heard the first syllable (/ə/), the first two syllables (/əōɛn/), and the entire word (/əōɛntɪk/). Sexual orientation ratings were the most accurate for the entire word and the least accurate for the first syllable. These results were replicated in experiment 2, which used only bisyllabic words. An items analysis from both experiments revealed that a syllable that contained more phones resulted in higher accuracy ratings compared with a syllable that contained fewer phones. For example, listeners’ sexual orientation ratings were more accurate when they heard the first syllable of “lavender” compared to the first syllable of “authentic.” These findings suggest that when the number of vowels is kept constant, listeners’ responses are more accurate if the utterance contains additional phones.
Lexically biased perceptual adaptation
Authors: McAuliffe Michael
Published: November 2013

Listeners are able to rapidly shift their acoustic-phonetic categories in the face of speaker-specific variation. However, an open question is how top-down expectations can influence this perceptual adaptation. Under Adaptive Resonance Theory [Grossberg (2003)], if an acoustic token provides initial activation of a linguistic category, top-down expectations about that category can boost the resonance and lead to activation of the category even with an ambiguous token. Ambiguous tokens in positions with stronger expectations are hypothesized to lead to less perceptual adaptation than in positions with lower expectations. To test this hypothesis, two groups of participants will be exposed to 10 ambiguous s-∫ sounds during a lexical decision exposure task. The groups differ in where in the word these sounds will occur, either in the onset or coda of CVC words. Lexical bias, as a form of top-down expectations, is stronger for ambiguous coda sounds [Pitt and Szostak (2012)]. I predict that in a s-∫ categorization task following exposure, the coda group will differ less than the onset group from a control group that only completes the categorization task, indicative of less perceptual adaptation.
Degraded word recognition in isolation vs a carrier phrase
Authors: Carbonell Kathy M. , Lotto Andrew J.
Published: November 2013

Recognizing a spoken word presented in isolation is a markedly different task from recognizing a word in a carrier phrase. The presence of a carrier phrase provides additional challenges such as lexical segmentation but also provides additional information relevant to word recognition such as speaking rate and talker-specific spectral characteristics. The current set of studies is part of an attempt to determine how target word recognition differs in isolation versus in a carrier phrase. In an initial experiment, a set of 220 spoken CVC words were noise-vocoded (6 channel) and presented to listeners either in isolation or following a noise-vocoded carrier phrase—“The next word on the list is…” The target words were transcribed in each condition and scored for initial consonant accuracy and overall word accuracy. Despite the lack of semantic or syntactic information provided by the carrier phrase accuracy for both word and consonant recognition were much higher in the carrier phrase context. A second experiment, used different talkers for the carrier phrase and target word. A smaller but significant benefit over isolation was present for these mixed talker stimuli suggesting that the benefits of the carrier phrase include, but are not limited to, talker-specific information.
Differences in the recognition of careful and casual speech
Authors: Sumner Meghan , Calder Jeremy , D'Onofrio Annette , McGowan Kevin B. , Pratt Teresa
Published: November 2013

Previous work in spoken word recognition and speech perception has shown two seemingly conflicting patterns. While some studies have shown a processing benefit for more frequent word variants (i.e., in a casual speech mode), others have found a benefit for more canonical word forms (i.e., in a careful speech mode). This study aims to reconcile these findings, proposing that different types of processing apply to each speech mode–top-down processing for casual speech, and bottom-up for careful speech. Listeners in an auditory priming task heard natural (non-spliced) sentences spoken in either a careful or casual speech mode. The final word of the auditory prime was either semantically predictable from the preceding sentence context or unpredictable. After the audio prime, listeners responded in a lexical decision task to a visual probe: either the final word heard in the prime, an unrelated word, or a nonword. Preliminary results suggest that, regardless of speech style, reaction times are faster for related targets in the semantically predictable conditions than for unrelated targets. Crucially, responses to the target word in the careful condition are delayed compared to casual speech for semantically unpredictable sentences. The implications for the apparent paradox in previous results will be discussed.
Effects of hearing loss and linguistic context for phoneme and word recognition in noise
Authors: Svec Adam , Munson Benjamin , Nelson Peggy B.
Published: November 2013

This project measured whole-word and phoneme recognition in normally hearing (NH) and hearing-impaired (HI) participants listening in steady-state noise. Stimuli were modeled after those used in Olsen et al. [EarHear 1997] including 10-word lists of consonant-vowel-consonant (CVC) monosyllables containing 10 vowels and 20 consonants. Words were presented in isolation and in contextually correct sentences. Speech-shaped noise was presented at a range of signal-to-noise ratios, from −9 to + 3 dB SNR for NH listeners, and from −6 to + 6 dB SNR for HI listeners. Results suggested that HI listeners needed an increased proportion of components (pp) to recognize a whole word (pw) relative to their NH counterparts (e.g., a higher j value) when stimuli were presented at unfavorable SNRs. For -3 and 0 dB SNR conditions, j factors for NH listeners (0 dB SNR: j = 2.17) were consistently lower than those for HI listeners (0 dB SNR: j = 2.52). However, for the 3 dB SNR conditions, j factors were higher for NH listeners (j = 3.06) than those for HI listeners (j = 2.58). This suggests an unexpected interaction between hearing acuity, background noise, and the recognition of phonemes versus whole words. [Research supported by DC008306 to Peggy Nelson.]
A word to the eyes: Visual cues benefit lexical segmentation in noise
Authors: Helms Tillery Kate , Cook Sarah J. , Utianski Rene L. , Liss Julie M. , Dorman Michael F.
Published: November 2013

In English, most word-initial syllables are stressed. Listeners use these syllable strength cues to identify word boundaries in degraded acoustic conditions. This is evident in the types of lexical boundary errors they make when tasked with parsing a continuous stream of degraded speech: word boundaries are more often inserted before strong syllables than before weak syllables. Listeners also use visual cues from the talker's face to glean both phonemic and prosodic speech information in degraded listening conditions. While the benefits of lipreading have received much attention, the role of visual cues in lexical segmentation remains largely unexplored. The present study examined the effect of auditory-visual cues on lexical boundary decisions. Normal-hearing listeners identified target phrases degraded by multi-talker babble. Responses in auditory-only and auditory-visual conditions were analyzed for percent words correct and lexical boundary error type. Results indicate large inter-individual variability, but overall an increase in word identification accuracy and a decrease in lexical boundary errors in the auditory-visual condition. Further, some listeners made a greater proportion of lexical boundary insertions before strong syllables, suggesting that the addition of visual cues increased their use of syllable strength to identify word boundaries. Implications for clinical populations will be discussed.
Talker familiarity effects on speech-in-speech perception
Authors: Cooper Angela , Bradlow Ann R.
Published: November 2013

Talker familiarity can facilitate the extraction of linguistic content from speech signals embedded in broadband noise; however, relatively little research has investigated the impact of talker familiarity with competing speech in the background. This study explores the effects of familiarity with the target or competing talker in speech-in-speech perception. Listeners were first familiarized with and trained to identify three female voices. They then completed a sentence recognition task in the presence of 1-talker babble. Familiarity with either the target or background talker was manipulated in separate conditions. Results revealed significantly better sentence recognition for familiar relative to unfamiliar target talkers in the presence of an unfamiliar background talker; however, sentence recognition with an unfamiliar target talker did not differ depending on background talker familiarity. Thus, while listeners were able to capitalize on familiarity with a talker’s voice to aid target speech recognition, familiarity with the competing talker was neither facilitative nor inhibitory. This suggests that the influence of talker familiarity is limited to the actively attended stream. This stands in contrast to other aspects of the unattended stream which have been shown to exert an influence on speech-in-speech recognition including language and semantic content of the background speech.
Defense applications of acoustic signal time delay estimation
Authors: Ferguson Brian G. , Lo Kam W.
Published: November 2013

Measurements of the differences in the times of arrival (or time delays) of a signal at spatially-separated sensors can be used to provide localization information about a source. For continuous broadband signals, the time delay for a given pair of sensors is estimated using the generalized cross-correlation method. The time delay estimate corresponds to the time lag at which the cross-correlation function attains its maximum value. The variance of the time delay estimates depends on the signal-to-noise ratio, signal bandwidth, and integration time. Errors in the source localization parameters depend on the variance of the time delay estimates as well as on the source-sensor geometry, stationarity of the sound propagation medium, uncertainty in the actual sensor positions, and the presence of multipath arrivals. Numerous practical examples of time delay estimation and the instantaneous localization of sources of military interest are presented for acoustic sensors deployed on land and under water. Also, localization performance is observed to degrade when the sound propagation medium becomes nonstationary, the direct path and multipath arrivals are unresolvable, or the differential Doppler effect is significant. Finally, the results of source motion parameter estimation using sequences of time delay estimates from pairs of sensors are presented.
Coordinated optimization of stationary and moving sensors with scenario-specific coverage and cost goals
Authors: Vecherin Sergey , Wilson D. Keith , Pettit Chris
Published: November 2013

The problem of simultaneously optimizing coverage among stationary sensors placed on the ground and moving sensors on aircraft is considered. The formulation extends a previously developed algorithm for optimizing placement of ground sensors subject to signal propagation effects and terrain-dependent coverage preferences. To this end, candidate aircraft routes should be characterized in terms of cost and coverage. Cost can reflect a variety of disincentives, for example, the probability that an aircraft can be heard on the ground. Coverage reflects the area of regions with probability of detection higher than a specified threshold. The extended algorithm can be applied to a variety of planning scenarios, such as determining an optimal combination of routes for multi-aircraft operations, optimization of aircraft routes to supplement ground-sensor coverage, optimization of ground sensors to cover blind spots of aircraft coverage, and simultaneous optimization of ground sensors and aircraft coverage. An illustrative problem of routing an unmanned aircraft system (UAS) to provide surveillance around a roadway while minimizing aircraft audibility at specified locations on the ground is considered in detail.
Performance comparison of distributed and centralized systems based on information
Authors: Yang Tsih C.
Published: November 2013

Distributed systems using many sensors widely distributed over a large area present an alternative way for target detection and environmental sensing. The diversity of opportunities for detection by widely distributed sensors seems attractive but the signals received on distributed sensors are usually not coherent due to the wide separations between the receivers. Hence, conventional approaches based on signal coherence/gain no longer apply. In this paper, information theory will be used to compare their performance. Treating the target radiated signal as a communication signal, transmitting continuous Gaussian-distributed alphabets, the Shannon channel capacity yields the maximum information that the receivers can learn about the (target) transmitted signal. The channel capacity can then be used as a metric to compare the performance of various sensor systems in the ideal case. Matched tracking processing is introduced to motivate a capacity-based detector and detection capacity. Based on that, it is found that the distributed systems can achieve in principle an area of coverage two to three times larger than that of a centralized system under the right conditions, and the area of coverage by the entire system can be significantly larger than the sum of detection areas of individual nodes.
Acoustic signatures of small boats measured in controlled lake conditions
Authors: Sutin Alexander , DeLorme Michael , Salloum Hady , Sedunov Alexander , Sedunov Nikolay , Weiss Robert , Tsionskiy Mikhail , Goheen Howard
Published: November 2013

Measurements were conducted under controlled conditions at Lake Hopatcong, NJ, to compare acoustic signatures of various small boats. The tested boats included: an outboard-driven Panga, a multiple-outboard driven go-fast boat, an electric drive vessel, a personal watercraft (PWC), and two small outboard-driven rigid hull inflatable boats (RIBs). Stevens Passive Acoustic Detection System (SPADES) was used for acoustic measurements and the specially developed “Portable Vessel Data System” (PVDS) was used to record vessel position, speed, shaft RPM, and vessel orientation. Vessel acoustic Source Level measurements were conducted by comparing the recorded vessel acoustic signals with a signal generated by a calibrated emitter from the same point. Dependencies of acoustic signatures on boat speed and loading were also investigated. For several vessels, the Source Level decreased when its speed increased. Analysis of tonal components in the vessels acoustic signatures with Detection of Envelope Modulation on Noise (DEMON) allowed to determine the number of engines per boat and even the gear ratio for transformation of shaft rotation to the propeller rotation. [This work was supported by DHS S&T.]
Practical applications of track segment association algorithms to an active sonar network for underwater port surveillance
Authors: Edson Patrick , Stein Peter J.
Published: November 2013

Acoustic detection and tracking of small (swimmer-size) targets while minimizing the incidents of false alerts can be challenging in a shallow, multipath, high-clutter harbor environment. One common problem involves track intermittency where periods or locations of high clutter or multipath interference inhibit detection and cause tracks to fail and restart. This paper describes the results of applying track segment association and related algorithms from airborne and ground radar applications [e.g., Zhang and Bar-Shalom, IEEE Trans. Aerosp. Electron. Syst. 47(3), 1899–1914 (2011)] to an active sonar network for underwater port surveillance [Edelson et al., J.Acoust. Soc. Am. 129(4), 2598 (2011), Stein et al., J. Acoust. Soc. Am. 121(5), 3084 (2007)] using real-world swimmer and synthetic target data.
Adaptive processing for mitigation of biologically induced active-sonar clutter and reverberation
Authors: Summers Jason E.
Published: November 2013

Scattering from biological entities can be a significant source of reverberation and clutter for active sonar systems operating in deep or shallow water. Resonant scattering from the swim bladders of fish is a dominant source of this biologically induced reverberation and clutter for midfrequency active sonar (1–10 kHz), which can obscure targets, result in false targets, and otherwise overload operators of tactical systems. Though significant questions remain regarding the fisheries oceanography needed to predict clutter and reverberation, the basic physics of scattering from individual fish and groups of fish is well understood. This motivates a data-driven, clutter adaptive approach to mitigation of biologically induced reverberation and clutter that utilizes physical models without requiring unavailable databases of fish-species abundance and local spatiotemporal distributions. In this work, physics-based models relating physical parameters of fish and their spatiotemporal behaviors to spectral properties and spatiotemporal distributions of scattering form the basis of in situ parameter estimation. In this presentation, adaptive processing developed for the early stages of the active-sonar processing chain using these in situ estimates is described, including waveform and matched-filter design and within and across-beam normalization. [Work supported by a NAVSEA Phase I SBIR award.]
Fast nearfield to farfield conversion for circular synthetic aperture sonar
Authors: Plotnick Daniel , Marston Phillip L.
Published: November 2013

Monostatic circular synthetic aperture sonar (CSAS) images are formed by processing azimuthal angle dependent backscattering from a target at a fixed distance from a collocated source/receiver. In the laboratory data is taken by fixing the source location and spinning the target via a rotating mount. Typical CSAS imaging algorithms [Marston et al., Proc. IEEE Oceans (2011); Ferguson et al., J. Acoust. Soc. Am. 117, 2915 (2005)] assume the scattering data are taken in the farfield. Experimental constraints may make farfield measurements impractical and thus require a target to be scanned in the nearfield. If left uncorrected, this results in distortions of the target image and possible distortions of the angular dependence of features. A fast approximate Hankel function based algorithm is presented that converts nearfield data to farfield data. Images and spectrograms of an extended target are compared for both cases. Spatial sampling requirements for data collection are also considered. [Work supported by ONR.]
Predicting internal waves of acoustical significance
Authors: Duda Timothy F.
Published: November 2013

The broad dynamic range of internal gravity wave periods and scale lengths, as well as the variable group geometries of these waves, means that they are responsible for a variety of acoustic propagation effects. As a result, their degree of acoustical significance and the specific effects that they cause depend on time and place. A variety of internal-wave (IW) acoustic effects will be reviewed, with analysis of the regimes where each effect may have first-order propagation consequences. Many of the effects are specific to details such as the IW amplitudes, the angle between acoustic and IW propagation paths (and thus IW direction), IW proximity to sound source and/or receiver, and whether the IW field can be considered to be a random medium or, alternatively, a set of identifiable scattering features. The current state of our knowledge motivates a question: To what degree are specific acoustically relevant aspects of the IW field, and thus the acoustic effects, predictable? The answer to this question is being investigated through efforts to build ocean models bridging large-scale ocean dynamics, smaller-scale IW, and submesoscale dynamics, plus two-dimensional and three-dimensional acoustic propagation behavior.
Anisotropy in horizontal plane for the sound propagation in the ocean in the presence of internal waves
Authors: Katsnelson Boris
Published: November 2013

Review of researches dedicated to the sound propagation in the presence of internal waves is presented (starting with Evgeny Malyuzhinets, 1959 and Owen Lee, 1961). Main attention is paid on dependence of properties of the sound field (for example, sound amplitude fluctuations) on direction of propagation in horizontal plane. It was established—three main mechanisms: mode coupling, adiabatic variations, and horizontal refraction can be manifested in dependence on direction of sound propagation relative wave front of internal waves. Theoretical results as well as results of numerical modeling are presented illustrating different properties of acoustical signals for mentioned mechanisms including dependence on mode number and frequency. Experimental observations are also presented confirming real manifestations of mentioned three mechanisms.
Modeling the nonlinear internal wave field for coastal acoustics
Authors: Newhall Arthur E. , Lin Ying-Tsong , Lynch James F. , Duda Timothy F. , Helfrich Karl R.
Published: November 2013

It is now well known that coastal nonlinear internal waves, a common ocean feature, have large effects on the propagation of sound in the coastal ocean. Modeling such waves for input to acoustic models using regional ocean numerical models is difficult due to the fine spatial and temporal resolution needed. A multi-university program called Integrated Ocean Dynamics and Acoustics (IODA) is addressing this problem using two approaches—one a two-way, direct nested ocean model approach, and the other a blending of mesoscale ocean models and fine scale internal wave models. In this talk, we will discuss the latter approach. Issues of the internal wave source positions, their nonlinear propagation, earth rotation effects, field interpolation, output verification and integration of the ocean model with acoustics codes will be discussed. The results going from an ocean model to fully 3-D acoustic fields will be presented. [Work sponsored by ONR MURI program.]
Modal interference and frequency striations induced by moving nonlinear internal waves
Authors: Yang Tsih C. , Liu Jin-Yuan
Published: November 2013

Spectrogram of a broadband signal propagated over distances often displays striated bands of constant acoustic intensity levels plotted against the range and frequency. This phenomenon is due to modal interference and the slope of the striation is related to the source range and frequency by the waveguide invariant parameter “beta.” As an application, one can estimate the range to a moving source based on the striation of the spectrogram (as a function of frequency and time), knowing the source velocity and the waveguide invariant parameter. Conversely, no frequency striation is expected in the spectrogram of the received signal when both the source and receiver are fixed (the frequency content remains unchanged with respect to time). However, when nonlinear internal waves, appearing as a train of moving solitons, are present in the propagation path, the spectrogram of the received signal will display frequency striations (with respect to time) even for a fixed source and receiver. This paper applies the mode coupling equation to calculate the modal interference, intensity fluctuation and the striation slope. Broadband spectrograms are simulated to show the frequency striation as the solitons move from the receiver to the source. Results from at-sea data will be presented for comparison.
Synthetic aperture sonar imaging of breaking internal wave structures
Authors: Lyons Anthony P. , Hansen Roy E. , Sæbø Torstein O. , Callow Hayden J.
Published: November 2013

In October 2012, the Centre for Maritime Research and Experimentation (CMRE) conducted the ARISE’12 trials from the NATO research vessel Alliance, off of Elba island, Italy. During this trial, data were collected by the Norwegian Research Defence Establishment (FFI) using a HUGIN AUV with interferometric synthetic aperture sonar (SAS). Large visible structures in the SAS images and in the SAS bathymetries were caused by features in the water column, called boluses, which formed after breaking internal wave events. Variation in backscattered intensity from the seabed was caused by focusing of sound by the bolus and errors in bathymetry by the changes in phase as the acoustic energy moved through the lower sound speed bolus. A ray model and a 3D parabolic equation (PE) model were used to simulate the effects of the bolus on the acoustic field incident on the bottom and results compared favorably with SAS data. Models for the change in bolus size and speed as it propagated upslope also gave reasonable comparison to estimates obtained from SAS intensity images. [The work performed by APL was supported by the US Office of Naval Research.]
Modeling sound propagation through internal waves using a spectral element method
Authors: Joshi Sumedh M. , Ballard Megan S. , Diamessis Peter J.
Published: November 2013

Considered here is the problem of low-frequency sound propagation over shallow, shoaling bathymetry in the presence of perturbations to the background sound velocity profile due to internal waves (IW). The question we attempt to answer is: to what degree can heuristic models of IWs coupled to numerical sound propagation models capture the variability in sound propagation observed in the environment? A high-order finite element model is employed to compute the acoustic field as it propagates through these IWs. The generality of the finite element method allows for spatial and temporal sound speed variations, and its convergence properties yield arbitrarily small error as the grid is rened. Simulations in the presence and absence of IWs will demonstrate the degree to which IWs influence sound propagation. Different models of IWs will demonstrate the sensitivity of the sound propagation to the choice of heuristic used for the IWs. Results will be shown for shoaling waveguides of O(100 m) depth and O(10 km) range, and frequencies of O(50 Hz). [Work supported by the NDSEG Fellowship.]
Estimates of source range using horizontal multipath in continental shelf environments
Authors: Ballard Megan S.
Published: November 2013

In a continental shelf environment, energy from an acoustic source propagating obliquely upslope repeatedly reflects from the sea surface and sloping seafloor with a consequent change in direction with each bottom reflection. Measurements of this type of effect can be observed in beamformed data from a horizontal line array. The arrivals from a single source are seen on two beams: a direct path with bearing angle corresponding to the source location and a refracted path with a bearing angle inshore of the source. In this work, the horizontal multipath effects are exploited to estimate the location of an acoustic source. Using the hybrid modeling approach of vertical modes and horizontal rays, rays are traced in the horizontal plane with refraction determined by the modal phase speed. Invoking reciprocity, the rays orientate from the center of the array and have launch angles equal to the estimated bearing angles of the direct and refracted paths. The location of the source in the horizontal plane is estimated from the point where the rays intersect. The technique is applied to data recorded on a horizontal line array located about 12 km east of the southern coast of Florida. [Work supported by ONR.]
Night club skylight vs. hotel—A case study
Authors: Kanter Shane J. , Giegold Carl , Walker Constance , Strong John
Published: November 2013

The Paris Club, a popular night club in Chicago, Illinois, is enclosed by an enormous, operable skylight. This feature spans across the entire space, acting as the only “barrier” between the club and the directly adjacent hotel and high end condominium buildings. From within the Paris Club, the condominium balconies and hotel windows are in direct line-of-site. Although the skylight is a wonderful architectural feature, it is devastating to the isolation of thumping music played within the club. Through various testing methods, the isolation performance was measured and required performance was determined. Calculations and a laboratory tested mockup yielded a viable solution.
Acoustical characteristics of restorative space on a university campus
Authors: Bristow Abigail , Horoshenkov Kirill V.
Published: November 2013

This paper explores the nature, sound environment, and value of restorative space on University campuses in the United Kingdom that is separated from standard teaching venues. Questionnaire surveys were undertaken in the Atrium and Student Central at the University of Bradford and in the Library at Loughborough University to explore expectations and perceptions of restorative quality, preferences, values, and use on non-teaching space. These spaces are used routinely by the students for social, relaxation, individual, and group studies. Contemporaneous, continuous measures of noise were undertaken at the survey locations. Noise levels in a social space on campus can be as high as 85 dB, which affects the restorative quality of the space. The results of these surveys enabled us to explore the link between the acoustical characteristics of a space and its restorative quality, and to identify key sounds which contribute to the value of a restorative space. The value of such spaces is reflected in the willingness to pay for quieter and greener spaces.
Design of a new restaurant and remedial design of an existing café: Reducing noise of patron activities
Authors: Pettyjohn Steve
Published: November 2013

R. Selands is an experienced restauranteur with an understanding of the importance of controlling excess sound, as was his architect from the Netherlands. When designing a new restaurant in Sacramento called Ella, acoustics was an important item. Both sound from the HVAC system and patron noise were evaluated. Acoustical treatment of patron noise had to fit in with the aesthetic plan by the architect. HVAC sound was controlled using specific wall and floor/ceiling design and spring isolation. The result was very successful with continuous compliments from patrons. Some issues still exist where a decision was made to not use acoustical treatment. When designing a new market and café, acoustics was not high on the list until the day the facility was opened. Within three days, calls were made requesting assistance to reduce or eliminate excess sound because of complaints from patrons. Site visits, limited field tests, and drawings were used to evaluate the architectural acoustics. Options were provided to modify room finishes to reduce the reverberation time within the space. The most difficult task was modifying the tin-type ceiling to allow sound absorptive material to be placed above.
Examining the relationship between room acoustics parameters and the cafe effect in restaurants
Authors: Reuter Eric L. , O'Connor Christopher
Published: November 2013

It is well known that the so-called café effect, the progressive increase in speech effort as an enclosed space becomes more crowded with talkers, is related to the reverberant characteristics of the room. This study attempts to correlate specific room acoustics parameters (total absorption, reverberation time, etc.) to the café effect through analysis of several existing restaurants. At each establishment, noise monitoring was conducted over the course of a busy weekend, followed by corresponding impulse response measurements in the empty room. Results and conclusions from the study will be presented.
Hierarchical effects of attention on amplitude modulation encoding in auditory cortex
Authors: Sutter Mitchell , O'Connor Kevin N. , Downer Joshua , Johnson Jeffrey , Niwa Mamiko
Published: November 2013

How attention influences single neuron responses in the auditory system remains unresolved. We found that when monkeys actively discriminated temporally amplitude modulated (AM) from unmodulated sounds, primary auditory (A1) and middle lateral belt (ML) cortical neurons better discriminated those sounds than when the monkeys were passively listening. This was true for both rate and temporal codes. Differences in AM responses and effects of attentional modulation on those responses suggest: (1) attention improves neurons’ ability to temporally follow modulation (2) non-synchronized responses play an important role in AM discrimination (3) ML attention-related increases in activity are stronger and longer-lasting for more difficult stimuli consistent with stimulus specific attention, whereas the results in A1 are more consistent with multiplicative nonlinearity, and (4) A1 and ML code AM differently; ML uses both increases and decreases in firing rate to encode modulation, while A1 primarily uses activity increases. These findings provide a crucial step to understanding both how the auditory system encodes temporal modulation and how attention impacts this code. Further, our findings support a model where rate and temporal coding work in parallel, permitting a multiplexed code for temporal modulation. [Work supported by NIDCD RO1 DC-02514.]
Individual identification of Japanese macaques by coo-calls: Pitch or vocal tract characteristics?
Authors: Furuyama Takafumi , Kobayasi Kohta I. , Riquimaroux Hiroshi
Published: November 2013

Japanese macaques, Macaca fuscata, utter the Smooth Early High (SEH), one of harmonically structured coo-calls, for greeting and locating other individuals. The purpose of this study was to examine acoustical features of SEH for them to identify the caller. Two male Japanese macaques were trained to discriminate SEHs of Macaque A (SEHa) from those of B (SEHb). The fundamental frequencies (pitch) of SEHa and SEHb were different. Those calls were recorded from monkeys unfamiliar to subjects. GO-NOGO paradigm was used for training the animals. SEHa served GO stimuli (S + ) while SEHb served NOGO stimuli (S-). A “Hit” was reinforced with about 1 ml of orange juice. Unfamiliar SEHa and SEHb, which were never used for training sessions, were used as test stimuli. A series of morphed SEHs between SEHa (S + ) and SEHb (S-) with only pitch or vocal tract characteristics varied were also used for test stimuli. Results showed that reaction times (RTs) for unfamiliar SEHa were significantly shorter than those for unfamiliar SEHb. RTs to morphed stimuli shortened as the distance from SEHb (S-) increased in both pitch and vocal tract dimensions. Data suggested that both pitch and vocal-tract characteristics were important for Japanese macaques to identify individuality.
Early experience improves neural discrimination/recognition of natural complex sounds
Authors: Bao Shaowen
Published: November 2013

In natural environments, behaviorally relevant complex sounds are often produced with “speaker” variability and contaminated with environmental noises. To efficiently discriminate/recognize natural complex sounds, the auditory system has to tune to defining acoustic features and filter out random, meaningless features. In humans, for example, efficient speech recognition is achieved by enhancing perceptual contrast for native speech sounds, as well as reducing perceptual contrast for non-native speech sounds. The neural mechanisms underlying this perceptual transformation are still not well understood. We exposed juvenile rats to heterospecific vocalizations recorded in a natural environment, and subsequently examined their cortical complex sound representations. Cortical neurons became more responsive to dynamic and complex features of the complex sounds. In addition, more neurons were involved in representing the whole set of complex sounds, but fewer neurons actually responded to each individual sound. Cortical responses to different renderings of the same song motif were more similar, and responses to sounds of different motifs became more distinctive, indicating that cortical neurons were more selective to the defining features of the experienced sounds. These effects lead to better neural discrimination/recognition of the experienced complex sounds.
Neural encoding of learned auditory feedback statistics in avian vocal-motor circuitry
Authors: Bouchard Kristofer E. , Brainard Michael S.
Published: November 2013

Many complex behaviors are supported by neurons with both sensory and motor properties. During behavior such sensory-motor neurons experience the probabilistic associations of pre-motor activity for current actions with feedback from previous actions. Consequently, these associations might become encoded through Hebbian mechanisms. To investigate this possibility, we measured whether and how auditory-motor neurons in the vocal premotor nucleus HVC of songbirds encode the relative probabilities that different syllable sequences were produced during singing. We recorded from HVC while playing pseudo-randomly sequenced syllables from the bird’s repertoire and found that auditory responses to syllables were positively modulated by the conditional probability that preceding sequences were produced during singing. Moreover, responses integrated over seven or more syllables, with the sign, gain, and temporal extent of integration depending strongly on probability. Our findings indicate that encoding of probabilistic associations between current and previous sounds may be a general principle of vocal-motor circuits.
Audiomotor activity in the superior colliculus of the big brown bat engaged in a natural, acoustic orientation task
Authors: Wohlgemuth Melville J. , Moss Cynthia F.
Published: November 2013

To accurately select and orient to a target, noisy, and multimodal sensory information about the target’s location must be integrated into a coordinated set of orienting movements. At the hub of sensorimotor integration for species-specific orientation is the superior colliculus (SC), a midbrain structure receiving multimodal sensory inputs and projecting to premotor nuclei throughout the brainstem. Our research brings together behavioral and chronic neural recording data to examine auditory and premotor activity in the SC of the echolocating big brown bat as it performs a natural, goal-directed task. We trained bats to rest on a platform and track a tethered insect moved by a computerized stepper motor system. While the bat was tracking and capturing insects, single neuron activity was recorded across superficial, intermediate, and deep layers of the SC. Neural activity across the laminae of the SC signal auditory and pre-motor events: Echoes reflected from the sonar target evoked activity in superficial and intermediate layers, while premotor activity related to pinna, head, and vocal-motor behaviors was found at deeper recording sites. Collectively, the results of this study contribute to a deeper understanding of midbrain audiomotor activity in the context of natural goal-directed tasks.
Targeted drug delivery to the brain and brain tumors using focused ultrasound and microbubbles
Authors: McDannold Nathan
Published: November 2013

The physiology of the vasculature in the central nervous system (CNS), which includes the blood-brain barrier (BBB) and other factors, severely limits the delivery of most drugs to the brain and to brain tumors. Focused ultrasound (FUS), when combined with circulating microbubbles, is a noninvasive method to locally and transiently disrupt the BBB at discrete targets and enhance delivery across the “blood-tumor barrier.” This talk aims to provide insight on the current status of this unique drug delivery technique, experience with it in preclinical models, and its potential for clinical translation. In particular, methods to monitor the procedure using acoustic receivers and the feasibility of controlling and predicting drug deposition will be reviewed. If this method, which offers a flexible means to target therapeutics to desired points or volumes in the brain, can be translated to the use in humans, it can enable the use of the whole arsenal of drugs in the CNS that are currently prevented by the BBB.
Ultrasound-based neurostimulation in the mouse model
Authors: Butts Pauly Kim , King Randy , Ye Patrick , Brown Julian
Published: November 2013

Ultrasound-based neurostimulation would be a useful tool prior to MR-guided focused ultrasound treatments in the brain. In this work, we report on our studies on ultrasound-based neurostimulation in the mouse model. We define the success rate as the ratio of the number of positive EMG responses to the number of sonications. A single element ultrasound transducer with a center frequency of 500 kHz was applied to the mouse head via a coupling column and coupling gel on the mouse head. EMG electrodes were placed in the mouse neck and tail muscles to measure contraction of the relevant muscles as the ultrasound transducer is moved across the mouse head. The success rate increases with ultrasound intensity or with ultrasound duration, following a sigmoidal curve. As the ultrasound frequency is increased, the ultrasound intensity must be increased for the same success rate. Movement of the ultrasound transducer across the brain changes the response in the relevant EMG systems such that the neck EMG response is stronger when the transducer is more rostrally placed, while the tail EMG response is stronger when the transducer is more caudally placed. Our findings present evidence for selective targeting in the mouse model of ultrasound-based neurostimulation.
Thermoacoustic sound projectors using carbon nanotubes and other nanostructures
Authors: Aliev Ali E. , Baughman Ray H.
Published: November 2013

The application of solid-state fabricated carbon nanotube sheets as thermoacoustic (TA) projectors is extended from air to underwater applications. Due to non-resonant sound generation, the emission spectrum of nanotube sheets in air or underwater varies smoothly over a wide frequency range, 1-105 Hz. Encapsulating the nanotube sheet projectors using inert gases with low heat capacity provided attractive performance at needed low frequencies, as well as a realized energy conversion efficiency in air of 0.2% and 1.5% underwater, which can be enhanced by further increasing the modulation temperature. We suggest enhancement of sound generation efficiency of encapsulated device by using high quality resonant acoustical windows and modulation of high frequency carrier current with a low frequency resonant envelope. Applications of TA projectors for high power sonar arrays and transparent flexible loudspeakers will be discussed. Finally, the alternative nanostructures for excitation of thermoacoustic sound waves will be surveyed. [We gratefully acknowledge support by Office of Naval Research grant N00014-13-1-0180.]
Alternative tonpilz and bender transducer designs
Authors: Butler John
Published: November 2013

Tonpilz transducer designs with half-wavelength water-sized radiating-pistons are commonly used in SONAR arrays. And here the tonpilz piston normally radiates in the broadside direction with reduced output as the array is steered to the end-fire direction. Bender transducer designs, used in low frequency applications, can take the form of a dipole transducer which, as a result of partial self-cancellation, can lead to a low source level output. We present two alternative transducer designs, which solve these problems. In the case of the tonpilz array, a cylindrical-shaped leveraged-transducer design with one-half water wavelength size and modal performance is proposed. This transducer is shown to operate in the first three modes allowing the formation of an element beam that may be steered in the general directions the array is steered, with full output in a single end-fire direction. In the case of the dipole transducer, advantage is taken of the strong near-field dipole acoustic pressure which is used to energize a nearby compliant parasitic resonator yielding a dominant monopole source of greater output. [Work supported in part by ONR.]