bluuebunny/crossref_metadata_2025 huggingface dataset:
The native language benefit for voice recognition is not contingent on lexical access
Authors: Monto Nicholas R. , Theodore Rachel M. , Orena Adriel J. , Polka Linda
Published: November 2016

Listeners show heightened talker recognition for native compared to nonnative speech, formalized as the language familiarity effect (LFE) for voice recognition. Some findings suggest that language comprehension is the locus of the LFE, while others implicate expertise with the linguistic sound structure. These hypotheses yield different predictions for the LFE with time-reversed speech, a manipulation that precludes lexical access but preserves some indexical and phonetic properties. Research to date shows discrepant results for the LFE with this impoverished signal. Here we reconcile this discrepancy by examining how the amount of exposure to talkers’ voices influences the LFE for time-reversed speech. Three experiments were conducted. In all, two groups of English monolinguals were trained and then tested on the identification of four English talkers and four French talkers; one group heard natural speech and the other group heard time-reversed speech. Across the experiments, we manipulated exposure to the voices in terms of number of training trials and duration of the talkers’ sentences. A robust LFE emerged in all cases, though the magnitude was attenuated as the amount of exposure decreased. These results are consistent with the account that the LFE for talker identification is linked to the sound structure of language.
Language familiarity mediates identification of bilingual talkers across languages
Authors: Orena Adriel John , Polka Linda , Theodore Rachel M.
Published: November 2016

Many studies show that listeners are more accurate at identifying talkers in their native language than in an unfamiliar language; yet, little is known about the nature of this language familiarity effect in bilingual speech. Here, we investigate the links between language and talker processing further by assessing listeners’ ability to identify bilingual talkers across languages. Two groups were recruited: English monolinguals and English-French bilinguals. Participants learned to identify bilinguals speaking in only one language (English); they were then tested on their ability to identify the same talkers speaking in the trained language (same language context: English) and in their other language (different language context: French). Both monolinguals and bilinguals showed above chance performance in identifying talkers in both language contexts at test, confirming that there is sufficient information in bilingual speech to generalize across languages. Moreover, the results showed a language context effect that was facilitated by language familiarity: monolinguals showed a substantial decrease in performance between the same and different language contexts, whereas the bilinguals—who understood both languages at test—showed only a slight decrease in performance between the two language contexts. These results indicate that language familiarity affects talker encoding and retrieval, even for bilingual speech.
Interspeech posture in Spanish-English bilingual adults
Authors: Shary Merrily R. , Betancourt Kyna S. , Frisch Stefan A. , Maxfield Nathan D.
Published: November 2016

Interspeech posture (ISP) is a term used to define the position of a person’s articulators when preparing to speak. Wilson and Gick (2014) found French-English bilinguals used different tongue posture during ISP depending on which language they were speaking. The authors suggested that ISP may be representative of a speaker’s phonological knowledge in a particular language but recommended other languages be examined. The purpose of this study was to replicate Wilson and Gick (2014) using Spanish-English bilingual speakers. To this end, bilingual Spanish-English adults were asked to produce sentences while speaking in monolingual and bilingual modes. While they were speaking, ultrasound images of the oral cavity were obtained and tongue tip height during each interutterance pause was measured. Additionally, monolingual English speakers rated the accentedness of each bilingual’s speech in English as a behavioral correlate of language proficiency. Overall results of this study supported Wilson and Gick (2014); bilingual Spanish-English speakers judged to be native sounding in English only utilized similar postures in monolingual and bilingual speaking modes. Different measures of ISP and speaker variability will also be completed to determine if there is a better method for measuring ISP in Spanish-English bilinguals.
A preliminary investigation of velar-vowel coarticulation in Spanish-English Bilinguals
Authors: Frisch Stefan , Allen Marsha , Betancourt Kyna , Maxfield Nathan
Published: November 2016

Coarticulation, the influence of one speech sound on another in running speech, has been suggested as an index of speech motor control. Therefore, proficient and stable coarticulation could be a diagnostic tool in language assessment and speech-language pathology. In the present study coarticulation was investigated in Spanish-English bilingual adults to determine whether velar-vowel coarticulation patterns differ in English versus Spanish. Velar-vowel coarticulation was measured in six Spanish-English bilingual university students. Participants recited sentences in blocks of English, Spanish, and a mix of both languages. Each sentence included a target word starting with /k/ + vowel. Tongue movement was recorded using a sub-mental ultrasound probe held in a stabilizing helmet. Ultrasound images were analyzed to identify tongue posture following procedures of Frisch & Wodzinski (2016, Journal of Phonetics, doi: 10.1016/j.wocn.2016.01.001). The results indicate a pattern similar to that found for Interspeech Posture in French-English bilinguals (Wilson & Gick, 2014, Journal of Speech, Language, Hearing Research, doi: 10.1044/2013JSLHR-S-12-0345). Some bilinguals showed a single pattern for both languages while others produced distinct velar postures between English and Spanish.
Speech sound naturalness alters compensation in response to transformed auditory feedback
Authors: Hiroya Sadao , Mochida Takemi
Published: November 2016

Articulatory compensations in response to real-time formant perturbation have revealed that auditory feedback plays an important role in speech production. However, these compensatory responses were at most 40% for formant shifts and varied depending on vowel type and subjects. Although previous formant perturbation studies have been done using linear predictive coding (LPC), it is known that the estimation accuracy for low vowels and female speech would be degraded due to a glottal source-vocal tract interaction. To improve the accuracy, we have developed a real-time robust formant tracking system using phase equalization-based autoregressive exogenous (PEAR) model which utilizes the glottal source signals measured by electroglottography. In this study, we compared compensatory responses to real-time formant perturbation using PEAR and LPC. Eleven Japanese subjects (seven females) read a Japanese mora (/hi/ or /he/) with headphones. The first two formant frequencies were altered. Results showed that compensatory responses using PEAR were significantly larger than LPC. Moreover, naturalness of altered speech sounds was improved by PEAR. This indicates that improving speech sound naturalness by PEAR led to larger compensatory responses. Therefore, our system would be useful to understand the auditory feedback mechanisms in more detail.
Speech stability as a characteristic of the individual
Authors: Frisch Stefan , Massey Jessica , Maxfield Nathan
Published: November 2016

Coarticulation, the influence of one speech sound on another in running speech, has been suggested as an index of speech motor control. Therefore, proficient and stable coarticulation could be a diagnostic tool in language assessment and speech-language pathology. In the present study, stability in the production of velar-vowel coarticulation was measured within speakers across experimental sessions to determine whether differences in stability can be attributed to individual differences in speech production ability. Velar-vowel coarticulation was recorded in children aged 8-12 in three sessions roughly one month apart. Participants recited sentences that included a target word starting with /k/ + vowel. Ultrasound images were analyzed to identify tongue posture and stability in posture across repetitions following procedures of Frisch, Maxfield, & Belmont (2016, Clinical Linguistics & Phonetics, doi:10.3109/02699206.2015.1137632). Preliminary analysis of two participants suggests there is less variation in stability within a participant across sessions than there is between participants. Analysis of the remaining participants is ongoing. This suggests that speech stability may indeed be a property of an individual speaker. If this finding holds, there are implications for models of speech production that include individual differences, including differences in language proficiency or clinical diagnosis.
Event related speech readiness potentials to spoken words and CV’s
Authors: Smith Silas , Sears Robert , Yonovitz Al
Published: November 2016

This study investigated the temporal and dynamics of brain activity to speech and motor preparation. Previous EEG studies have identified a slow negativity wave that occurs previous to the onset of speech. Brain electrical potentials were obtained in subjects prior to initiation of speech in a using a single vertex electrode. Both a repeated single syllable word and CV’s were used. The sample rate permitted an analysis of both slow negative waves and faster neurogenic signals. The purpose of this research was to establish a real-time event related brain electrical potential system. This research uses a vocal signal as the marking point, and displays in real time the event-related potential. Each time epoch was sampled at 25600 samples/sec. One second of these signals were averaged for 100 trials just prior to initiation of the word “pool” or a randomly presented CV. The inter-trial interval was approximately 25 seconds. For the 100 trials, each trial was saved. Separate odd and even event potentials were averaged. The obtained waveform (pre-speech) was consistent and reliable between and within subjects. The microstructure of the waveform was also obtained showing specific waveform morphology. The reliability was greater for the CV productions.
Differential frequency hopping performance in doubly spread underwater acoustic communication channels
Authors: Edelson Geoffrey S. , Cazzanti Luca
Published: November 2016

Underwater acoustic communication requires waveforms that are robust to the signal distortions caused by the channel. Many waveforms used for this purpose require the transmission of training symbols that span the inter-symbol interference (ISI) to compensate for these channel effects. Differential frequency hopping (DFH) is a fast frequency hopping, digital signaling technology that requires minimal information at the transmitter to communicate in the underwater channel. The relationships between the parameters of Doppler spread-inducing underwater environments and DFH bit-error performance are characterized. Wind speed determines the nature of the effect that the water surface imposes on acoustic DFH waveforms with low wind speeds resulting in an essentially flat, low-absorption sea surface. In this case, strong surface reflections and little frequency spreading make ISI the dominant effect on the received waveforms. At high wind speeds, air bubbles in the surface layer absorb almost all energy incident on the surface, resulting in no surface reflections reaching the receiver so that the surface has little effect on the received signal. The intermediate ranges of wind speed, with a mix of ISI and surface-induced Doppler spread, pose the greatest challenge. Simulations and at-sea experiments show that DFH performance is robust across environmental conditions.
Multichannel equalization method based on vector time-reversal and decision feedback equalizer technology
Authors: Sheng Xueli , Ruan Yewu , Lu Dian , Yin JIngwei , Guo Longxiang
Published: November 2016

A kind of underwater communication receiver combined with Vector Time-Reversal algorithm and multichannel decision feedback equalizer (VTR-MDFE) is studied, which can address the problem of inter-symbol interference and waveform distortion, resulting from time-varying multipath channel. Impacts of environmental noise can be suppressed by use of vector sensor’s combined directivity and Corresponding vector signal processing technology. Meanwhile, error rate is reduced while system capacity is enhanced by time-reversal algorithm’s anti-multipath ability. The performance of VTR-MDFE are proved by simulated results in the communication channel provided by a ray-based acoustic model, for different ocean conditions and source-receiver geometries.
Application of maximum entropy to statistical inference for inversion of data from a single track segment
Authors: Stotts Steven A. , Koch Robert A.
Published: November 2016

An approach is presented for statistical inference, based on maximum entropy (ME) with inversion data from a single source track segment, to account for model mismatch. A previous approach requires data from multiple track segments to set the, otherwise undetermined, ME constraint value specifying the posterior probability density (PPD). One effect of mismatch is that the lowest cost inversion solutions for some parameter values, e.g., source track parameter values obtained from GPS measurements or source levels from towed sources, may be well outside a relatively well known, narrow, uncertainty interval. The basis for the new approach is that the ME constraint value is determined by requiring for such a parameter value that the inferred uncertainty interval encompass the entire uncertainty interval comprising its prior information. Motivating this approach is the hypothesis that the proposed constraint determination, applied to the PPD for a model space broader than that parameter value’s prior, could account for the effect of mismatch on the inferred, but a priori less well defined, values for other parameters.
On the dependence of the nonlinearity coefficient of marine silica sands on grain size, shape, and packing density
Authors: Sanders William , Reed Allen , Wood Warren
Published: November 2016

Several applications of parametric sonars rely on utilizing nonlinear propagation of sound in marine sediments. Whereas it has been speculated that the nonlinearity coefficient for granular materials is expected to be relatively high, few measurements have been made to support the notion, nor has any theory been used to satisfactorily predict the parameter. Moreover, unlike fluids, the nonlinearity coefficient of granular materials does not follow from an equation of state, but is likely the composite effect of multiple mechanisms. Hence, we aim to compile a comprehensive set of measurements of the nonlinearity coefficient for a variety of sediments and conditions. This effort reports on the initial set of observations on unconsolidated quartz silica sands in water with grain sizes ranging from 0.05 to 1 mm, a variety of shapes (angular, sub-rounded, and rounded), and a variation in packing density. [This work was supported by ONR.]
Near-field measurements of a parametric source
Authors: Sanders William , Reed Allen , Wood Warren
Published: November 2016

In order to characterize nonlinear interactions within granular materials, measurements were made in the near-field of a 50 kHz transducer (an ITC 5270). High-resolution beam patterns were observed which reveal significant diffraction effects. Observed beam patterns were used to predict the difference frequency signal and this resulted in more than a 10 dB difference from that predicted by assuming constant amplitudes. This points to an inadequacy of the typical treatment of the parametric field as that due to collimated beams of constant amplitude in the near field, e.g. as in the Moffet and Mellen model. [This work was supported by ONR.]
Perturbation theory for mode coupling over a sloping penetrable bottom
Authors: Zhu Feilong , Thorsos Eric I.
Published: November 2016

In environments with water depth variations, one-way modal solutions involve mode coupling. One approach is to model the depth variation as a series of steps, and use a new set of modes at each step (Evans, JASA, 1983). Higham and Tindle (JASA, 2003) developed an accurate and faster approach using perturbation theory to locally determine the change in mode functions at steps and limit the required number of new sets of mode functions. The method of Higham and Tindle is limited to low frequency (< 250 Hz). We have extended the coupled mode perturbation method so it can apply to higher frequencies. The approach will be described and some examples shown.
Elucidation of a mechanism of acoustic impedance technique using two cardioid microphones and ensemble averaging method
Authors: Hoshi Kazuma , Hanyu Toshiki
Published: November 2016

Recently, there is growing need for in-situ impedance measurement of several materials. We propose using two cardioid microphones (called C-C sensor) for it. C-C sensor has many advantages against two omnidirectional microphones (called P-P sensor) and one omnidirectional microphone and sound velocity (called P-U sensor). I reported the possibility of using C-C sensor for measuring acoustic impedance on 12th Western Pacific Acoustics Conference 2015 (WESPAC2015) and International Congress on Acoustics 2016 (ICA2016). When measuring some porous materials, C-C method can measure acoustic impedance as same as using P-P method, and C-C method can do it from 100 Hz to over 10 kHz. Next, we tried to elucidate the mechanism of using C-C sensor and Ensemble Averaging (EA) method using numerical experiments. As a result, the range in application of C-C sensor for measuring acoustic impedance was clarified. In this presentation, we'll introduce the measuring technique and mechanism.
A case for modular partitions in healthcare facilities
Authors: Jurdy Basel , Gray Kathleen
Published: November 2016

In healthcare, good acoustic separation between rooms is critical for speech privacy and user comfort. While there are multiple factors that contribute to acoustic separation, this is usually achieved by increasing the acoustical performance of the separating architecture between rooms. This is done by running a wall of a specific Sound Transmission Class (STC) to structure to minimize flanking paths. However, running a modular wall up to or slightly above the ceiling tile can reduce the cost of construction and improve programmatic flexibility. In situations where the wall runs only to the ceiling, the acoustic ceiling tile (ACT) and plenum condition begins to play a large role in the acoustic performance of the separating architecture. Given a high-performing ACT, a high-STC modular wall, and partially open plenum, is there a condition where good speech privacy can be achieved between rooms without running walls to structure? This was examined with a mock-up for EvergreenHealth in Kirkland, WA. The results show that given certain plenum conditions and a CAC-40 tile, the separating architecture using a modular partition can perform at the minimum STC-45 separation between patient rooms set by the 2014 Facility Guidelines Institute (FGI) for healthcare facilities.
Objective acoustical quality in healthcare office facilities
Authors: Hodgson Murray
Published: November 2016

Health-care facilities include many non-clinical office spaces for administrative staff; the role of acoustics in these spaces has been underexplored. This paper discusses the acoustical part of a study of indoor environmental quality (IEQ) in 17 healthcare office facilities. Physical acoustical measurements were made in six types of rooms, some with sound-masking systems, to determine the acoustical characteristics, assess their quality, relate them to the building designs, and develop prediction models. Background-noise levels were measured in the occupied buildings. In the unoccupied buildings, measurements were made of reverberation times, and “speech” levels needed to calculate speech intelligibility indices for speech intelligibility and speech privacy. In open offices, sound-level reductions per distance doubling (DL2) were measured. Noise isolations of internal partitions of different designs (double-plasterboard construction, modular or built in-situ, rising to the suspended ceiling or to the floor-ceiling slab, without and with doors, different amounts of glass) were measured. The acoustical characteristics were compared to design criteria to evaluate their acceptability. The results are presented, and are related to room type and partition design. An empirical model for predicting partition noise isolation, developed using regression techniques, is discussed. The knowledge gained from this study informs the decision-making of designers and facilities management for upgrades and future design projects.
Intra-click time-frequency patterns across the echolocation beam of a beluga whale
Authors: Starkhammar Josefin , Reinhold Isabella , Moore Patrick , Houser Dorian , Sandsten Maria
Published: November 2016

The echolocation beam of toothed whales has been studied ever since it was first discovered in 1960. Recent studies have focused on the frequency distributions across the cross sections of the beams. Other studies have focussed on describing the entire acoustic field around the animal. However, no one has yet described the timing of each frequency component in the main lobe beam in relation to the other frequency components. Even though the echolocation clicks of broadband click species like the beluga whales (Delphinapterus leucas) are short in time (around 70 μs), previous results have shown indications on a frequency dependence with time, within each click. Little is known about the details of how the signal is generated and transmitted into the water. Investigations of when in time the frequency components occur within each click would give us further knowledge to how the signals are generated. This study takes a closer look at these intra-click time-frequency patterns across the echolocation beam of a beluga whale. This is done by analyzing echolocation clicks with a novel reassigned spectrogram method, developed especially for separating and determining time and frequency locations of multi-component transient signals.
Nonlinearities in the vocalizations of Stenella species in the Southwest Atlantic Ocean
Authors: Moron Juliana R. , de Castro Franciele R. , Andriolo Artur
Published: November 2016

Some complex features found in tonal emissions may be the result of nonlinear phenomena in sound production systems, which may result in individually acoustic signals highly variable and complex. From the analysis of five opportunistic acoustic records of distinct groups, two of spinner (Stenella longirostris) and three of Atlantic spotted dolphins (Stenella frontalis), we registered the emission of six different types of nonlinearities. Spinner dolphins had less events presenting mostly biphonation in the form of nonparallel bands and subharmonics. Atlantic spotted dolphins presented a higher rate of these features presenting mostly biphonation and screams on their vocalizations. Although the exact function of these processes is still being investigated, recent documentation in several species suggests that they may play a communicative role. Describing the occurrence of these characteristics can indicate their level of importance, as well as its structure may be indicative of its function. This is the first record of these events in Stenella species in the Southwest Atlantic Ocean. Future studies that allow to associate the behavior of these species while emitting these signals would greatly increase the understanding of these events. This study was funded by Chevron.
Neural-inspired segmentation of audio streams into phone-like units
Authors: Roch Marie A.
Published: November 2016

Recent work has shown that the human preauditory and/or auditory cortex is likely to play a role in acoustic landmark processing, such as the recognition of syllable and phoneme boundaries. Neurons appear to track acoustic envelopes with neural activity corresponding well with acoustic landmarks. These structures have also been observed in non-human primates, suggesting that acoustic landmark processing could be present in non-human primates and have an evolutionary role. Should landmark processing occur in non-humans, it could provide new methods for approaching animal communication. In this work, we use a simplified computer model to examine envelopes of acoustic signals that were filtered through a series of octave spaced band-pass filters. Peaks are detected in the signal envelopes with closely spaced peaks suppressed for a period of time after the first detection. Preliminary work shows an ability to detect human phoneme boundaries with a recall of 45% and a precision of 72% on the TIMIT speech corpus. The TIMIT corpus contains phoneme-level transcriptions and successful matches were defined as detecting landmarks within 20 ms of the over quarter million TIMIT phoneme boundaries. We also show qualitative results of the system for segmenting non-human primate calls into phone-like units.
Call concatenation in non-primate mammals
Authors: Manser Marta B.
Published: November 2016

Animals produce a variety of call sequences, from simple repetitions of the same acoustic unit to the combination of different, meaningful acoustic units resulting in a new meaning. On the example of several highly vocal mongoose species, including meerkats (Suricata suricatta), and banded mongoose (Mungos mungo) I identify the composition of different acoustic combinations and relate them to their function and meaning. I discuss this in regards to the underlying cognitive mechanisms and the differences and similarities in relation to other combinatorial communication systems in birds, but particularly shown for primates, and also to human language.
Coastal observation systems to monitor physical, chemical, and biological parameters
Authors: Yamazaki Hidekatsu , Masunaga Eiji , Gallager Scott , Tanaka Mamoru , Takeuchi Marika , Amakasu Kazuo , Kondo Hayato
Published: November 2016

We have developed a free-fall multi-parameter profiler (YODA Profiler) to measure various physical and biological parameters in coastal ocean. We found internal bores create a strong mixing event. Sediment resuspension is associated with the mixing event and also AZFP detected fish school at the front of bore. We have deployed a cable observatory system (Oshima Coastal Environment data Acquisition Network System, OCEANS) in a coastal area to monitor coastal ecosystem continuously. OCEANS can measure various physical, chemical and biological parameters simultaneously, and operates a plankton imaging system (Continuous Plankton Imaging and Classification System, CPICS). Based on acquired images of phytoplankton and zooplankton, we are investigating how planktonic biodiversity is affected by multi-scale physical processes, such as Kuroshio and internal waves. We are developing a technique to predict the biodiversity of plankton from three-dimensional hydrodynamic model using a newly developed plankton ecosystem model. We are also developing a AUV (MEMO-pen) that carries CPICS as well as microstructure profiler (TurboMAP) in order to simultaneously observe turbulence and plankton. We will introduce the most recent results from these observation systems.
Seasonal and interannual changes in the sound scattering layer at deep-sea floor in the Amundsen Sea, Antarctica
Authors: La Hyoung Sul , Park Keyhong , Wåhlin Anna , Ha Ho Kyung , Atkinson Angus , Fielding Sophie , Kim Dong Sun , Yang Eun Jin , Kim Tae Wan , Lee SangHoon , Im JungHo , Shin Hyoung Chul
Published: November 2016

Vertical migration of zooplankton is ubiquitous behavior in marine plankton community; however, seasonal and interannual behavior are little observed in the deep sea under seasonal varying sea ice. Here, the first evidence that sound scattering layers of zooplankton can support the knowledge for understanding the effect of climate change is presented, based on four-years acoustic backscattering strengths in the Amundsen Sea, Antarctica. Amundsen Sea is a biological hotspot region with the rapid oceanic melting of the ice shelf as well as the most productive (per unit area) in the Antarctic. High-temporal resolution profiles of acoustic backscattering strength collected from a bottom-moored, upward looking Acoustic Doppler Current Profiler were examined to describe the temporal variation of sound scattering layers. Our observations show that sound scattering layers exhibited clear diel, seasonal, and interannual pattern associated with solar radiation, sea ice concentration, and phytoplankton biomass. The timing of seasonal variation is also closely related with climate index for Southern Annular Mode and El Niño Southern Oscillation. This observation points out that acoustic signals from sound scattering layers could be a proxy to understand zooplankton ecosystem response to climate shifts.
Comparison of the volume backscattering strength measured by EK60 and EK80
Authors: Mukai Tohru , Amakasu Kazuo
Published: November 2016

Walleye pollack (Gadus chalcogrammus) resources are abundant around Hokkaido in Japan. The acoustic survey of the walleye pollack using the quantitative echo-sounder has been performed around Hokkaido since 1995. The quantitative echo-sounder that is mainly used for this survey is the EK60 system consisting of GPT + ER60 software made by Simrad. On the other hand, EK80 system using the WBT has been released in 2015, and the acoustic survey will be conducted by EK80 system from now. Therefore, it is necessary to examine whether the acoustic data measured by the EK60 and EK80 systems are identical. In this study, in the area where sound scattering layer was seen, these two systems were used alternately on the same track line to examine whether there are differences in the acoustic data to be measured. Systems used in this study were GPT in frequency 38, 120, and 200 kHz, controlled by ER60 (Ver.2.4.3) and WBT in CW mode at 120, 200 kHz controlled by EK80 (Ver.1.8.3). The acoustic data of the same transect were collected by both systems. The difference of SV between both systems will be discussed.
Broadband acoustics: A viable tool for quantification of cod egg density and distribution?
Authors: Macaulay Gavin , Ona Egil , Kubilius Rokas , Godø Olav Rune
Published: November 2016

Fish eggs are ichthyoplankton with a similar behavior in the water column as small zooplankton. Their specific density relative to sea water determines their vertical distribution and spread; horizontal transport of the layers will then determine their fate and geographical position during the hatching of the larvae. Acoustic techniques are routinely used to assess the quantities and distribution of fish populations. In comparison to fish, zooplankton and ichthyoplankton are very weak acoustic reflectors and this makes the application of acoustic techniques challenging. We assessed the potential feasibility of using broadband acoustics to detect cod eggs in a two stage process: first, we carried out small-scale tank experiments to measure the acoustic reflectivity of individual and grouped cod eggs over the 170 to 360 kHz frequency range. These experiments showed that natural densities of cod eggs could be detected above the background acoustic noise level. This lead to the second stage whereby we conducted a field test in an area with known concentrations of cod eggs, using a combined acoustic-optical towed and moored system. We postulate that the high spatial resolution, yet rapid wide area coverage possible with acoustics will lead to a better description of egg distributions and subsequent larval distributions and help to understand the extremely variable recruitment success in sub-arctic and arctic ecosystems.
Mid-frequency clutter and reverberation characteristics of fish in a shallow ocean waveguide
Authors: Lee Wu-Jung , Tang Dajun , Thorsos Eric I.
Published: November 2016

Horizontal-looking, mid-frequency sonar systems allow synoptic underwater observation over kilometer scales and are useful for a wide range of applications. However, quantitative assessment of fish aggregations using such systems in a shallow water environment is challenging due to the complexity of sound interactions with the surface and seafloor. Based on data collected during TREX13 (Target and Reverberation Experiment 2013), this study investigates methods to reliably distinguish fish echoes from background contributions to reverberation. The data were collected on a fixed, horizontal receiving line array from a source transmitting linear frequency-modulated signals in the band between 1.8 and 3.6 kHz. The experimental site was nearly isodepth (approximately 20 m) and characterized by a well-mixed, isothermal water column. Fish echoes were ubiquitously found in the data, with noticeable differences between day and night. In a particularly interesting case, a large aggregation of fish was observed emerging from a shipwreck, evolving in space, obscuring the wreck echoes temporarily, and eventually dispersing and disappearing into the overall reverberation background. Using a physics-based approach, the scattering level, statistical features, and spatial characteristics of both the fish echoes and background reverberation in this data set were analyzed and modeled. [Work supported by the APL postdoctoral fellowship and ONR.]
Heterogeneity of deep scattering layer shapes the Bahamian mesopelagic ecosystem
Authors: Sato Mei , Benoit-Bird Kelly J.
Published: November 2016

We explored deep scattering layers off the Bahamas where the beaked whales have been historically observed. By comparing the habitats frequently used by the beaked whales with the ones rarely utilized, we examined the differences in mesopelagic ecosystem potentially driving the whales’ prey habitat through bottom-up control. Using ship-based multifrequency echosounders and direct net sampling, we identified common layer structures characterized by the diffuse, broad layers (>100 m in thickness) observed across the study site. Within those diffuse layers, we occasionally observed distinctively bounded intense layers (~20 m in thickness) located at the upper edges. Instead of a specific layer structure dominating the habitat characteristics, we found that heterogeneity of the layer structures shaped the preferred habitat of beaked whales. Frequently used habitat was characterized by evenly distributed diffuse layers alone, or combined with patchy thin layers. Less-used habitat showed diverse characteristics such as diffuse layers combined with highly variable patchiness of the thin layers. The layer depth, its thickness, and frequency response were not related to the preference of the habitats. Heterogeneity of the layer structures reveals the dynamics of the mesopelagic ecosystem, potentially impacting higher trophic levels.
Celebration of Floyd Dunn: Some remarks about his life, career, and accomplishments
Authors: O'Brien W. D.
Published: November 2016

No Celebration of Floyd Dunn would be complete without some remarks about the life, career, and accomplishments of this remarkable scientist/engineer. 1946 is a key year in the history when Floyd arrived at the University of Illinois as an undergraduate student, having served in the European Theater during World War II. The same year, William J. (Bill) Fry and Francis J. (Frank) Fry were hired by the University of Illinois, and the Bioacoustics Research Laboratory was established (70 years ago!). Floyd had made significant scholarly contributions in six general themes. The six ultrasonic biophysics themes include: absorptive processes, nonlinear phenomena, application in living systems, toxicity, measurement techniques, and ultrasonic microscopy. Floyd has been recognized for his accomplishments by being the recipient of most the important national and international awards including: National Academy of Sciences, National Academy of Engineering, ASA’s Gold Medal and Silver Medal in Bioresponse to Vibration, Acoustical Society of Japan’s Medal of Special Merit, IEEE’s Edison Medal, and election to Fellowship in six professional societies.
Non-invasive in-situ quantitative observation of biological cells by acoustic microscopy
Authors: Hozumi Naohiro , Takanashi Kyoichi , Washiya Mamoru , Yoshida Sachiko , Kobayashi Kazuto , Saijo Yoshifumi
Published: November 2016

Several ways of quantitatively observing biological cells will be exhibited. Cells are cultured on a thin plastic film in order to make is possible to access by high-frequency acoustic beam focused onto the cell. Reflection waveform has a spectrum briefly spreading from 100 to 400 MHz. Mechanical scan makes it possible to acquire a 2-D profile. Cells in contact with the substrate can be characterized by means of characteristic acoustic impedance. In most of observations, buffer liquid that is simultaneously observed with cells may be employed as the reference material for calibration. In the process of cell culture, some of the cells may be delaminated from the substrate. In such a case significant error in acoustic impedance measurement may take place. In order to avoid such an error waveform separation is performed. As a result of such a waveform analysis, delamination distance may be calculated as well as the acoustic impedance of the cell that is slightly distant from the substrate. As an example C2C12 cells that develop into muscle tissue were observed after differentiation-inducing. Finally, feasibility of cross-sectional observation of cells will be discussed by showing some examples.
Evolution of acoustic microscopy in the commercial marketplace
Authors: Kessler Lawrence W.
Published: November 2016

The promise of Acoustic Microscopy from the 1970s,—to image features and structures of samples from a micromechanical aspect—has found a few niche markets in industry, and, in particular, defect detection in manufactured products. The hope for its widespread application in medicine and pathology has not yet been reached in the commercial market, though there are several pockets of significant biomedical research that employ acoustic microscopy methods. This paper will give this author’s perspective on the field from his 40 years of experience at Sonoscan, Inc., a company originally founded to explore commercial applications, and whose primary activities have found to be serving the semiconductor and microelectronics industries. Based on the original Ultrasonic Absorption Microscope paper by Dunn and Fry in 1959, the early commercial technique substituted a scanning laser as an acoustic detector for their thermocouple probe to produce two dimensional acoustic images.
At the Intersection: Science, fatherhood, and historical events. Unscientific remarks about Floyd Dunn through the lens of his career at the meeting point of historical events, fatherhood, and possibility
Authors: Dunn Roo
Published: November 2016

Floyd’s 60 years of scientific contributions to ultrasonic biophysics and his life experiences created, and crossed with, many of the thrilling and tumultuous events of the 20th and early 21st centuries. We will consider national and global events in economics, war, geopolitics, cosmology, and black holes. This paper will look at these topics through conversations spanning some 40 years. We will examine how they meshed with his life, family and the hypotheticals that were frequently discussed which might have drastically altered the outcome. The material is based on informal talks between father, son, and youngest grandson.
Low-energy extracorporeal shock wave therapy, preclinical and clinical studies
Authors: Greenleaf James F. , Carrascal Carolina A. , Urban Matthew W. , Kinnick Randy , Lerman Amir , Lerman lilach
Published: November 2016

Floyd Dunn’s extensive research career contributed significantly to safety and efficacy of diagnostic and therapeutic ultrasound. Positive effects of low-energy shock wave therapy (SWT) show preclinical promise in renal disease in pigs and in cardiovascular disease in humans. Preclinical: a set of 26 pigs were divided into four groups, normal + SWT, atherosclerotic renal artery stenosis (ARAS) + SWT, and Normal and ARAS pigs. After three weeks of ARAS or sham, SWT was applied twice a week for three weeks. SWT after ARAS decreased blood pressure, recovered the stenotic microvascular density, improved renal blood flow and glomerular filtration rate, and decreased fibrosis. No noticeable kidney injury was observed. Low-energy SWT recovers the stenotic kidney toward normal function by preserving intra-renal microcirculation and may also alleviate renovascular hypertension. 72 patients with refractory angina, 43 were treated with low-energy SWT in the area peripheral to their infarct and 29 patients were in the control group. No adverse effects were seen in the treated group. At six months post-treatment angina class score was decreased (p = 0.0002), nitroglycerine use was reduced (p = 0.03), and hospitalization rate was reduced (p = 0.03). Low-energy shockwave therapy may be a tool for treating diseases caused by ischemia.
Ultrasound and microbubbles induced extravasation in a machine-perfused pig liver
Authors: Averkiou Michalakis A. , Keravnou Christina P. , De Cock Ine
Published: November 2016

Ultrasound driven microbubbles interact with capillaries and cells and have been proposed to be beneficial for localized drug delivery and uptake. Some of the mechanisms involved is transient cell membrane permeability alteration and vessel poration which increase particle extravasation. Ex vivo machine perfusion of human-sized organs is a technique that provides an ideal environment for preclinical investigations with high physiological relevance not possible with in vitro experiments. In this work, ex vivo machine-perfused pig livers combined with an image-guided therapy system were used to investigate extravasation induced by ultrasound driven microbubbles. Local microvascular flow changes (measured by contrast enhanced ultrasound) and leakage of Evans blue dye in liver parenchyma were used to assess the degree of extravasation. 1—4 MPa peak negative pressure and 20—1000 cycles were considered. Liver areas that were exposed to long pulses (1000 cycles) and peak negative pressure >2.5 MPa showed a detectable perfusion change. Two fold increase in Evans blue concentration was observed at areas treated with peak negative pressure above 1 MPa and 500 cycles, indicating that extravasation still occurs in lower pressures where flow changes cannot be detected with contrast enhanced ultrasound quantification.
Enhanced high rate shockwave lithotripsy stone comminution in an in-vivo porcine model using acoustic bubble coalescence
Authors: Alavi Tamaddoni Hedieh , Roberts William W. , Duryea Alexander P. , Hall Timothy L.
Published: November 2016

While cavitation on the surface of urinary stones has been shown to aid stone fragmentation, bubbles along the propagation path away from the stone may attenuate shockwaves. We have shown applying low amplitude acoustic waves after each shockwave can force bubble coalescence enhancing lithotripsy efficacy in vitro. For the present study, we demonstrate the feasibility of applying acoustic bubble coalescence (ABC) in vivo. Artificial model stones were percutaneously implanted in the right kidney of ten 50 kg female pigs and treated with 2500 shockwaves at 120 SW/min with or without ABC. ABC sequences consisted 1 MPa tone bursts at 500 kHz for a total duration of 16 ms. After treatment, kidneys were removed and dissected. Remaining fragments in the kidney were retrieved and filtered for size. Comparing size distributions, a significant improvement was observed when ABC was used. Without ABC, only 25% of the remnant mass of fragments was less than 2 mm. With ABC, 75% of the mass was less than 2 mm. These results suggest ABC can reduce the shielding of cavitation bubbles resulting in a more efficient SWL treatment.
Analysis of the electrostatic ultrasonic airborne actuator using the finite-difference time-domain method
Authors: Igai Ryosuke , Shibamata Takefumi , Kurosawa Minoru K.
Published: November 2016

We have investigated the structure of an electrostatic airborne ultrasonic actuator by using the FDTD method. The actuator structure has low-mass pleat-fold diaphragms. The pleat designed 10 mm deep and 2 mm wide, vibrate at a frequency range of 10 kHz to 200 kHz. The diaphragms of the pleat vibrate and carry out high power and wide directivity ultrasonic sound waves from a narrow output opening end. We have found the correlation between the depth of the pleat and the wavelength that the sound pressure level had peak and dip depending on the frequency. Using numerical simulation by the FDTD method, the interference in the pleat animated and described visibly. Instead of the plane wave source that caused the interference of the sound source in the pleats, progressive wave sources have mitigated interference and gained higher outputs. In the FDTD simulation, progressive wave source at 200 kHz generated 73 dBSPL and about + 30 dBSPL higher compared to the plane wave when the vibration amplitude and velocity were 33 micron and 41 mm/s at the diaphragm surface. The particle velocity at output point compared to the sound source gained 4.9 times faster at 20 kHz and 7.3 times faster at 200 kHz.
Some investigations on properties of spatial principal components analysis of individual head-related transfer functions
Authors: Takane Shouichi
Published: November 2016

Analysis for compact representation of spatial change of Head-Related Transfer Functions (HRTFs) based on principal components analysis (PCA), called Spatial PCA (SPCA), is investigated in this report. Although the SPCA of HRTFs has been researched for about 30 years, there exist some questions left unclear. In this report, the author tries to answer the following two questions: (1) how much amount of data (number of subjects and/or directions) is enough for generation of principal components, and (2) which domain (impulse response, frequency spectrum, etc.) is the best for compact representation of individual HRTFs based on the SPCA. As for (1), the amount of data may be relatively small as a result of the preliminary investigation, meaning that the HRTFs of a certain subject can be reconstructed by using the SPCA with the HRTFs of the other subjects of relatively small numbers. As for (2), the author concluded that the complex frequency spectrum brings about the most compact representation as the results of the SPCA of a single Head-and-Torso Simulator (HATS) [S. Takane, Appl. Acoust. 101, 64-77(2016)]. In this report, whether the same results are obtained or not is examined via comparison of the reconstruction accuracy among the individual subjects. [A part of this research was supported by JSPS KAKENHI (25330202).]
Localization of acoustic source in windy environment using ray tracing
Authors: Go Yeong-Ju , Choi Donghun , Lee Jaehyung , Choi Jong-Soo
Published: November 2016

Position estimation of sound source using ray tracing method is introduced based on wind field measurement. TDOA (time difference of arrival) estimate error occurs during outdoor sound measurement due to the atmospheric condition such as wind, temperature, humidity and so on. Such condition can possibly change the trajectories of rays. It produces erroneous propagation time information accordingly. In this study, simplex method is used to estimate the source position using ray tracing. The basic concept is to find the estimation point which generates smallest mean square error of propagation distances or times from the candidate points. At first the estimation area is set around the first estimate which is calculated from the TDOA estimation. The simplex method is then applied to each point in the estimation area. Nelder-Mead simplex method is used to find the best position that produces the minimum error in travelling distances. In order to apply the ray tracing, the wind distribution is interpolated based on the wind measurements around the boundary. Simulation and experiments are conducted to verify the performance of the algorithm.