bluuebunny/crossref_metadata_2025 huggingface dataset:
Using an autonomous underwater vehicle to track the changing arctic ambient noise field in real time
Authors: Fried Stephanie , Schmidt Henrik
Published: November 2013

The ambient noise field, particularly the directionality of the noise, can provide a wealth of information about the local environment. Changes in the ambient noise field often reflect changes in the physical environment. Accurate calculation of the noise field, though, can be a challenge. Because of their maneuverability autonomous underwater vehicles (AUVs) provide novel capabilities not only for measuring and analyzing the local noise field, but also for continuous tracking of changes to the noise field and thus the environment. Of interest is the measurement and analysis of the ambient noise in arctic environments. By integrating models for arctic ambient noise into an AUV simulation, this paper analyzes the use of AUVs in real-time autonomous tracking of the three-dimensional changing arctic ambient noise field.
Interdecadal trends in ocean ambient sound at seven sites in the northern Pacific Ocean basin
Authors: Andrew Rex K. , Howe Bruce M. , Mercer James A.
Published: November 2013

A long-term observation program begun in approximately 1994 has amassed time-series of ambient sound short-time spectra from omni-directional hydrophones deployed on the ocean floor at seven locations in the northern Pacific Ocean. Each time-series consists of spectra estimated every 5 min over a useful band of 10–500 Hz, thereby encompassing the vocalizations of baleen whales, the anthropogenic contribution of ship traffic noise, and wind/wave noise due to sea surface processes. Simple linear trend lines show that traffic noise in the northern and northwestern reaches of the Pacific has increased by as much as 3 to 4 dB during this program. In the eastern North Pacific, however, the ambient sound shows a decrease of about 3 dB. The number of ships in the world merchant fleet increased by approximately 25% over this period. This change is insufficient to explain the increases in noise levels along northern and northwestern regions, and provides no explanation for the decreases observed in the north-east. The traffic noise field is evidently dependent on more complex temporal and geographical patterns of shipping traffic. [Work supported by ONR.]
Correlating acoustical with physical and biological oceanography
Authors: Parnum Iain , Erbe Christine , Verma Arti
Published: November 2013

The Centre for Marine Science & Technology at Curtin University built and maintains the underwater acoustic recorders of Australia’s Integrated Marine Observing System (IMOS; http://IMOS.org.au). Recordings have been obtained at four locations (off Western Australia, Victoria, and New South Wales) since 2011. IMOS includes a multitude of oceanographic and remote sensors, contributed by various institutions, which are also responsible for data management. Data are shared and publicly available encouraging collaboration and syntheses. This study has compiled time series of weather data, tides, current data (from Acoustic Doppler Current Profilers, ADCP), and wind (from radar measurements), and established correlations with underwater noise is a series of one-third octave bands between 10 Hz and 3 kHz from the Perth Canyon. Our results further demonstrate that ocean noise in certain frequency bands can be used to estimate aspects of physical and biological oceanography.
Undersea noise characterization using vector sensors and adaptive particle filters
Authors: Lindwall Dennis , DelBalzo Don , Charalampidis Dimitrios , Leclere Jim , Yoerger E. J. , Ioup George
Published: November 2013

Acoustic noise in the ocean is spatially complex and dynamic. It results from a composite of moving discrete and distributed sources with narrow and broadband signatures from near and distant locations over complex propagation paths. Whether the goal of noise characterization is to improve understanding of the sources and environmental aspects of noise or to find and describe weak signals, it can be better achieved with vector acoustic data and vector-based analysis rather than with a pure scalar-pressure approach. We will show analytically and with realistic acoustic noise simulations that the vector characterization of noise parameters such as directional distribution, frequency content, and time variation is more accurate and can be done with simpler instrumentation than what is commonly done with pressure data. We employ adaptive particle filters to model and estimate the temporal aspects of the noise fields. The filter's state and observation vectors consist of signal directions and magnitudes, respectively. As a result, the noise fields are directly associated with the filter's process and observation noise.
Model-based feasibility assessment and evaluation of prostate hyperthermia with a commercial MRI-guided endorectal high intensity focused ultrasound ablation array
Authors: Salgaonkar Vasant A. , Rieke Viola , Ozhinsky Eugene , Prakash Punit , Plata Juan , Kurhanewicz John , Hsu I-C (Joe) , Diederich Chris J.
Published: November 2013

Numerical simulations were conducted to devise methods for targeted and protracted hyperthermia (40–46 °C, 30–60 min) to the prostate with a commercial MR-guided endorectal ultrasound phased array (2.3 MHz, ExAblate, InSightec). The intention is to fast-track clinical implementation of this FDA approved ablation system for delivering targeted hyperthermia in conjunction with radiation or chemotherapy. Conformable hyperthermia to focal tumors in posterior and hemi-gland prostate was simulated through 3D patient-specific biothermal models and beamformed acoustic patterns that incorporated the specific constraints imposed on the ExAblate array: irregular element spacing, switching speeds, operating power and short pulse duration. Simulations indicated that diverging and iso-phase sonications could treat (T > 41 °C, max < 46 °C) 13–23 cm3 with ~1.1 W/cm2, multi-focused patterns could treat 4.0 cm3 with 3.4 W/cm2, and curvilinear patterns could treat 6.5 cm3 with 0.8 W/cm2 while avoiding rectum, urethra, pubic bone, etc. Custom beamforming identified through simulations was implemented on the ExAblate system and sonications were performed in tissue mimicking phantom material. ExAblate delivered long duration sonications (0.86 W/cm2) with these customized beamforming patterns and generated diffuse hyperthermia (ΔT = 4–8 °C) in phantom, monitored with real-time multi-slice MR temperature imaging (3T). [NIH R01CA122276, Focused Ultrasound Foundation.]
High intensity focused ultrasound laparoscopic instrument for partial nephrectomy
Authors: Mitchell Stuart , Wang Yak-Nam , Harper Jonathan , Hsi Ryan , Crum Lawrence
Published: November 2013

Partial nephrectomy (PN) is the gold standard for small clinically localized renal masses because of equal oncologic outcomes and greater preservation of renal function compared with radical nephrectomy (RN). However, it is a complex operation due to the challenges of cutting into a well-vascularized organ and the need for reconstruction of the remaining kidney following excision. PN is associated with higher blood loss, risk of transfusion, and longer operative time compared to RN. High intensity focused ultrasound (HIFU) affords the ability to ablate tissue and perform hemostasis, thus potentially mitigating some of the challenges associated with PN. The purpose of this paper is to introduce a new HIFU clamp as an adjunctive tool for PN. A HIFU device was created to conform to the shape of a commonly used laparoscopic instrument. Characterization studies were conducted using ex vivo tissue. Histology was performed to evaluate thermal damage. Ex vivo studies indicated that complete ablation planes could be achieved at temperatures sufficient for thermal tissue necrosis. Gross parenchymal changes were observed with clear demarcation between treated and untreated regions. Histological evaluations revealed that there were no viable cells in ablated regions. [This work was funded by NIH (EB013365).]
Optimization of parameters for therapeutic applications of high intensity myocardial contrast echocardiography
Authors: Miller Douglas , Dou Chunyan , Owens Gabe E. , Kripfgans Oliver D.
Published: November 2013

High intensity myocardial contrast echocardiography (HI-MCE) can lethally injure cardiomyocytes leaving scattered microlesions. This cavitational bioeffect may be of value for graded tissue-reduction therapy for conditions such as hypertrophic cardiomyopathy. Anesthetized rats in a heated water bath were treated with 1.5 MHz focused ultrasound, which was guided by an 8 MHz diagnostic imaging probe. Eight-pulse bursts were triggered intermittently over 5 min at approximately end systole during contrast microbubble infusion. The relative efficacy between 2 MPa (~173 W/cm2 IPA) or 4 MPa (~892 W/cm2) pulses, 1:4 or 1:8 trigger intervals, and 5 or 10 cycle pulses was explored in 6 groups. ECG premature complexes (PCs) induced by the triggered pulse bursts were counted, and microlesions assessed in Evans blue-stained cardiomyocyte scores (SCSs). The increase from 2 to 4 MPa produced significant increases in PCs and SCSs. In addition, the higher pressure eliminated the decline in the rate of PC induction over time, which was seen at 2 MPa and likely hindered therapeutic efficacy. Neither increased trigger intervals nor pulse durations yielded significant increases in therapeutic effects. High concentrations of microlesions were readily produced, which suggest that HI-MCE can be refined into a clinically robust method for therapeutic myocardial reduction.
Synergy between high intensity focused ultrasound and ethanol injection in ablation of thyroid cancer cells
Authors: Murad Hakm , Hoang Nguyen H. , Ratnayaka Sithira H. , Tsumagari Koji , Kandil Emad , Khismatullin Damir
Published: November 2013

We have investigated the combination of high intensity focused ultrasound (HIFU) and ethanol injection for ablation treatment of anaplastic thyroid cancer, a highly aggressive form of thyroid cancer characterized by >80% mortality within months. The suspension of FB1 anaplastic thyroid cancer cells (100 μl, 2.7 million cells/ml) were placed in a 0.2 ml thin-wall PCR tube and then exposed to HIFU alone, ethanol alone, or ethanol + HIFU. The focused ultrasound signal was generated by a 1.1 MHz transducer with acoustic power ranged from 4.1 W to 12.0 W. Ethanol was diluted in the FB1 cell growth medium to the concentration of 2%, 4%, or 10% (v/v) and applied to the cells before HIFU exposure. The viability of the cells was measured by flow cytometry and trypan blue exclusion 2, 24, and 72 h post-treatment. The exposure of FB1 cells to HIFU alone greatly reduced the number of viable cells immediately after treatment; however, their proliferation rate remained high. On the other hand, both the viability and proliferation rate significantly decreased in the cells treated with both ethanol and HIFU. In conclusion, percutaneous ethanol injection (PEI) and HIFU have a synergistic effect on anaplastic thyroid cancer ablation.
Histotripsy beyond the “intrinsic” cavitation threshold using very short ultrasound pulses: “Microtripsy”
Authors: Lin Kuang-Wei , Kim Yohan , Maxwell Adam D. , Wang Tzu-Yin , Hall Timothy L. , Xu Zhen , Fowlkes Brian , Cain Charles A.
Published: November 2013

Conventional histotripsy uses pulses with ≥3 cycles wherein the bubble cloud formation relies on the pressure-release scattering of the positive shock fronts from sparsely distributed cavitation bubbles. In a recent work, the peak negative pressure (P(-)) threshold for the generation of dense bubble clouds directly by a negative half cycle were measured, and this threshold has been called the “intrinsic threshold.” In this work, characteristics of lesions generated with this intrinsic threshold mechanism were investigated using RBC phantoms and excised canine tissues. A 32-element, PZT-8, 500 kHz therapy transducer was used to generate short (<2 cycles) histotripsy pulses at PRF = 1Hz and P(-) = 24.5–80.7 MPa. The results showed that the spatial extent of the histotripsy-induced lesions increased as the applied P(-) increased, and the lesion sizes corresponded well to the estimates of the focal regions above the intrinsic threshold. The sizes for the smallest reproducible lesions averaged 0.9 × 1.7mm (lateral × axial), significantly smaller than −6 dB beamwidth of the transducer (1.8 × 4.0 mm). These results suggest that predictable, well-confined and microscopic lesions can be precisely generated using the intrinsic threshold mechanism. Since the supra-threshold portion of the negative half cycle can be precisely controlled, lesions considerably less than a wavelength are easily produced (“microtripsy”).
Microphone array with computer vision based directivity
Authors: Messier Marc , Reimers Jordan
Published: November 2013

In the field of acoustic signal processing, one of the most popular areas of research is that of microphone arrays. As a small research project in this field, a microphone array system with adjustable polar response will be developed. To make research more innovative and multi-disciplinary, the polar response of the array will be controlled by a facial tracking system implemented with computer vision techniques. This research will take part as a means of combining coursework and research for courses in engineering acoustics, computer vision, and real-time digital signal processing at the University of Miami. Before any physical testing, simulations will be performed in Matlab to determine optimum array configurations and to analyze various facial tracking and dsp algorithms. Then, using a Texas Instruments TMS320C6713 DSP on a DSK audio target board, and writing code in C, Assembly, and Matlab, physical tests will be conducted to analyze performance of design. A MEMS microphone model will likely be used for its small size and low cost. A Microsoft Kinect and compatible desktop computer will be used for the computer vision interface. From there, results will be analyzed and further research in the area proposed.
Development of a multi-resonance transducer for highly directional underwater communication
Authors: Hwang Yonghwan , Je Yub , Lee Jaeil , Lee Jonghyeon , Kim Wonho , Seo Heesun , Moon Wonkyu
Published: November 2013

The parametric array is a nonlinear conversion process that generates a narrow beam of low-frequency sound using small aperture. It can be applied to underwater communication between two nodes with known locations, since the highly directional sound beam may provide such benefits as privacy, no interference due to the multi-path. The difference frequency wave (DFW) from the parametric array shows small side lobes and extraordinary directivity. The shortcoming of the DFW generated by the parametric array may be its low sound pressure level relative to that of the directly generated sound beams. In this study, we designed and fabricated a multi-resonance transducer as a parametric array source and evaluated its feasibility as a transmitter. For that purpose, we determined the proper design parameters for midrange communication. We selected 10 kHz as the communication frequency and then determined the primary frequencies as 100 and 110 kHz. We composed the source transducer using the two kinds of unit transducers. The fabricated transducer array and the developed operating techniques enabled us to successfully transmit letters, words, and drawings inside the water tank. By testing the characteristics, we confirmed that the developed operating scheme and transducer can be used for underwater communication. [Work supported by ADD (UD130007DD).]
A first look into the caxirola—Official music instrument of the Soccer World Cup 2014
Authors: Pozzer Talita , Paul Stephan
Published: November 2013

For the 2014 Soccer World Cup Brazilian Musician Carlinhos Brown created the caxirola as the official music instrument, adapting an old African instrument—the caxixi. Both caxixi and caxirola generate sound by hard particles impacting on the walls of a closed basket. While the basket of the caxixi is made of natural materials the basket of the caxirola is made of environmentally friendly polymer. Remembering the acoustical impact of the vuvuzela in 2010 as quite negative it was decided to study the acoustics of the caxirola. First, the way people will use the caxirola in terms of arm's excursion and velocity of shaking was studied. It was found that the caxirola was used moving it longitudinally and perpendicularly to its main axis, both in vertical direction. Spectra of the sound emitted by the caxirola and caxixi moving perpendicularly are quite similar with slightly more low frequency energy. However, when subjected to longitudinal movements, spectra are different. For the caxirola, the particle impact sound on the walls is the same for all impacted walls but for the caxixi, where lateral walls are of different material than the bottom, the spectra shows more energy for impacts at bottom.
Active structural acoustic control using a sum of weighted spatial gradients control metric
Authors: Johnson William R. , Hendricks Daniel R. , Anderson Monty J. , Blotter Jonathan D. , Sommerfeldt Scott D.
Published: November 2013

Active structural acoustic control (ASAC) is an active noise control technique, which provides global control by targeting and minimizing the structural vibrations which contribute to radiated sound power. The majority of research in ASAC has focused on validating various proposed concepts on flat rectangular plates, an important but not comprehensive class of structures. To extend the body of knowledge, ASAC has been investigated on finite ribbed plates under a variety of boundary conditions. Simulated results have shown that two different approaches, minimizing the volume velocity and minimizing the weighted sum of spatial gradients (WSSG) provide comparable average attenuation of radiated sound power on ribbed plates. With regards to sensing, minimizing WSSG has several advantages over minimizing volume velocity. In particular, WSSG has been formulated to be easier to measure than volume velocity, without requiring a priori information about the structure or its modes. WSSG has also been shown to be relatively uniform spatially and relatively insensitive to boundary conditions, while also providing improved control over volume velocity at structural modes higher than the first mode. These results suggest that more practical, complex vibrating structures can be effectively controlled for the reduction of radiated sound power using the WSSG approach.
Active control of sound transmission through soft-cored sandwich panels using volume velocity cancellation
Authors: Sahu Kiran C. , Tuhkuri Prof. Jukka
Published: November 2013

In this paper, the active control of harmonic sound transmitted through soft-cored sandwich panels into a rectangular enclosure is studied. As it has already been shown that in the low frequency region, the noise transmission through soft-cored sandwich panels mainly occurs due to flexural and dilatational modes [Rimas Vaicaitis, NASA Technical Note, NASA TN D-8516, 1977]; therefore, in this study, volume velocity cancellation control strategy is used to control these modes, and achieve sound attenuation in a broad frequency range. Point force and uniformly distributed force actuators are used as the secondary source to cancel the volume velocity of the inner surface of the sandwich panel which is open to cavity. Cancelling the net volume velocity of this is compared not only in terms of the reduction in sound power in the enclosure but also in terms of the plate velocities. Numerical studies indicate that the active control method controls both the flexural and dilatational modes and therefore, attenuates significant amount of sound power inside the cavity irrespective of the isotropic loss factors of the viscoelastic core. Also a finite element study has been done in the commercially available COMSOLMultiphysics software to compare with the analytical result.
Effect of modeling errors on virtual sensing systems for active noise control
Authors: Vicente Luis
Published: November 2013

In the active noise control literature, there are a number of algorithms based on the virtual sensing approach. In all of them, the aim is to control the noise at a position apart from the physical sensors, by somehow estimating the actual signal at that point. The benefit of such an arrangement is evident. However, the practical difficulties found when trying to achieve a properly working virtual sensing system surely are the main reason for a reduced number of successful applications reported. In this paper, we analyze and quantify those difficulties for several virtual sensing algorithms. All of them are based on some modeling that needs to be made previous to the actual control. We focus on the effect that errors on these models have on the stability of the whole system, the cancellation capability and the convergence rate. We check that the sensitivity of the cancellation capability to modeling errors is much higher in the virtual sensing case, when compared to that of systems with physical sensors on the desired points of cancellation.
Echo removal in tubular acoustic systems: Passive and active techniques
Authors: Groves Keir H. , Lennox Barry
Published: November 2013

Acoustic pulse reflectometry (APR) has been shown to be a very capable means of identifying features in tubular objects. APR systems excite a test object with a sound wave and listen for reflections, indicating the presence of features in the test object. An undesirable effect of this process is that the returning sound wave is re-reflected by the loudspeaker and re-enters the system. This paper presents two complimentary techniques that may be used to remove unwanted echoes in APR systems. The first approach uses two axially separated microphones to separate forward and backward propagating waves. This passive technique is shown to be highly capable of cancelling undesired echoes in the system. The second approach actively cancels unwanted echoes by introducing a phase inverted version of the wave that is incident on the loudspeaker. The active cancellation operates in real-time using the measured backwards propagating wave. As a consequence of the proposed techniques, the effectiveness of APR when applied to detecting features within tubular systems is improved considerably. The empirical results presented at the conference will demonstrate that corrosion effects, such as holes and pits, located in short lengths of pipes, can be detected clearly within seconds.
The effects of the orifice plate structure on the aerodynamic noise in the high parameter pressure reducing valve
Authors: Wei Lin , Jin Zhijiang
Published: November 2013

The high velocity steam flow in the high pressure reducing valve can cause loud noise, which is harmful to the operators and the relevant devices. The orifice plate is used to reduce the noise in the pressure reducing valve. The main objective is to study the relationship between the orifice plate structure and the aerodynamic noise in the high pressure reducing valve. Based on computational fluid dynamics hybrid approach was used to simulate the flow and the acoustic field in the valve. The thickness of the plate, the length between the plate and the plug, the bore diameter and its distribution were changed to analyze their effects on aerodynamic noise.
Lightning characterization through acoustic measurements
Authors: Gallin Louis-Jonardan , Rénier Mathieu , Gaudard Éric , Farges Thomas , Marchiano Régis , Coulouvrat François
Published: November 2013

Lightning generated acoustic shock waves are the most frequent natural explosions: they are good candidates to probe meteorological local properties of the acoustic propagation medium over distances of less than 100 km. The goal of the Ph.D. is to study the transformation the thunder undergoes (amplitude, spectrum) during its travel from the lightning channel towards a detector (microphone, microbarograph), the work is based on two complementary approaches: first the Flhoward software (UPMC) designed to simulate the propagation of acoustic shock waves through a realistic atmosphere model (including temperature gradients, rigid ground, and winds) will help us studying the traveling waveforms. And in second the analysis of the acoustic records (audible and infrasounds) obtained during the PEACH campaign (Autumn 2012) will provide data to which simulations will be confronted.
Where am I, where is the sound source?
Authors: William Yost A. , Zhong Xuan , Najam Anbar
Published: November 2013

Locating sound sources in the everyday world often involves listeners and sources who change location. Since sound source localization cues are relative changing when the listener or source moves, veridical and accurate sound source localization when the listener moves requires that the auditory brain “knows” where the listener is in 3-dimensional space. Experiments were conducted in a sound-deadened room with 36 loudspeakers located on a 5-foot radius sphere and a rotating chair. The listener was rotated in accelerating, decelerating, and constant velocity conditions and was either sighted (eyes open) or blind folded (eyes closed). The sound source was either fixed at one location, or the sound (100-ms, broadband noise) changed position from one loudspeaker to the next (along a 24-loudspeaker azimuth circle) in an accelerating, decelerating, or constant velocity manner. In all cases but one, listeners were able to perceive the loudspeaker presenting the sound in the same way they did when the listener was stationary. When the eyes were closed (no visual cues) and the chair was rotated at constant velocity (no semicircular canal vestibular cues), listeners badly misperceived sound source locations. The results indicate that veridical sound source localization requires visual and/or vestibular information.
Characterization of a spark source focused by an ellipsoidal reflector
Authors: Dai Xiaowei , Tsai Yi-Te , Haberman Michael R. , Zhu Jinying
Published: November 2013

Air-coupled ultrasonic non-destructive testing (NDT) provides an ideal solution for rapid scanning of large specimens. Unfortunately, despite decades of research, many challenges remain to render air-coupled ultrasonic methods a broadly effective sensing modality for high impedance materials due to low energy transmission between air and the solids being inspected. In this paper, we present experimental results and theoretical analysis of an electrical spark source focused by an ellipsoidal reflector. This acoustic source, which generates a short duration, high amplitude signal in air, is of high interest for air-coupled NDT for high impedance materials and has been shown to excite wave motion in concrete without contact. Theoretical modeling using weak shock theory and the KZK equation is used to predict the temporal and spatial features of the pressure field in the region of the geometric focus. We also present a series of experimental studies that characterize the spark generated acoustic wave in both free-field and the focused conditions. The bandwidth and directivity of the focused spark source are shown to be adjustable by changing the spark gap size and the reflector geometry. Finally, experimental results from three reflectors made of different material and geometries are presented.
Dynamic acousto-elasticity in Berea sandstone: Influence of the strain rate
Authors: Riviere Jacques , Candela Thibault , Scuderi Marco , Marone Chris , Guyer Robert , Johnson Paul A.
Published: November 2013

In comparison with standard nonlinear ultrasonic methods such as frequency mixing or resonance based measurements that allow one to extract average, bulk variations of modulus and attenuation versus strain level, dynamic acousto-elasticity (DAE) allows to obtain the elastic behavior over the entire dynamic cycle, detailing the full nonlinear behavior under tension and compression, including hysteresis and memory effects. To improve our understanding of these phenomena, this work aims at comparing static and dynamic acousto-elasticity to evaluate the influence of strain rate. To this purpose, we perform acousto-elasticity on a sample of Berea sandstone and a glass beads pack, oscillating them from 0.001 to 10 Hz. These results are then compared to DAE measurements made in the kHz range. We observe that the average decrease in modulus increases with frequency, meaning that conditioning effects are higher at high strain rate, when relaxation characteristic time is higher than the oscillation period. This result, together with previous quasi-static measurements (Claytor et al., GRL 2009) showing that the hysteretic behavior disappears when the protocol is performed at a very low strain-rate, confirms that a rate dependent nonlinear elastic model has to considered for a more complete description (Gusev et al., PRB 2004).
The use of high rise terminals in Southern Californian English
Authors: Ritchart Amanda , Arvaniti Amalia
Published: November 2013

This study investigates High Rise Terminals (HRTs), i.e., utterance-final rising pitch movements, as used in Southern Californian English (SoCalE), examining the phonetics and phonology of HRTs and their relation to pragmatic functions. Twelve female and 11 male speakers were recorded during a map task and in the retelling of a sitcom scene. HRTs were coded for discourse function (statement, question, confirmation request, floor holding) based on context. The alignment of the pitch rise start was measured from the onset of the utterance’s last stressed vowel, and the rise’s final Hz value was recorded. In HRTs used for statements, the rise started within the stressed vowel, while in questions it started after vowel offset. Together with the low F0 on the stressed syllable, this pattern suggests that statements have a L*L-H% melody while questions have L*H-H%. Confirmation requests and floor holding were more variable in alignment. Consistent differences in pitch scaling were found in the order: questions, confirmation requests > floor holding > statements. Females used HRTs more often than males, and their HRTs showed greater pitch excursion and later alignment. In conclusion, SoCalE uses different HRT melodies than other varieties and maintains a distinction between HRTs for statements and questions.
Mon voice registers: Acoustics and laryngeal control
Authors: Abramsonn Arthur S. , Tiede Mark K. , Luangthongkum Theraphan
Published: November 2013

Mon is spoken in many villages in Thailand and Myanmar. The dialect of Ban Nakhonchum, Ratchaburi Province, Thailand, has two voice registers, modal and breathy, phonation types that, along with other phonetic properties, commonly distinguish registers. Four native speakers recorded several repetitions of 14 randomized words (seven minimal pairs) for acoustic analysis. We used a subset of these pairs for listening tests to verify the perceptual robustness of the distinction. Four speakers, three of the original ones and one new one, were also recorded using electroglottography (EGG) while repeating the word set several times. The listening tests showed the distinction to be robust. Acoustic analysis of both sets of recordings was done using the UCLA VoiceSauce program. Differences in noise component (ratio of harmonics to noise and cepstral peak prominence), spectral slope, fundamental frequency, and formant frequencies all differ across the registers. For analysis of the EGG data we used the UCLA EGGWorks program to obtain closure quotient (CQ) measures. CQ was significantly different for all four speakers with higher values for the modal register. The salience of these cues in maintaining the register distinction will be discussed. [Work supported by NIH grants and the Thailand Research Fund.]
Reduction and frequency analyses of vowels and consonants in the Buckeye speech corpus
Authors: Yang Byunggon
Published: November 2013

In a casual conversation American speakers tend to talk fast and to reduce or change sounds of phonetic symbols defined in an English dictionary which we would find in citation speech style. This study examined how much reduction of pronunciation Americans make from the dictionary prescribed symbols to the real speech ones and how frequently Americans use vowels and consonants in the Buckeye speech corpus. The corpus was recorded by 40 American male and female subjects for an hour per each subject. Results were as follows: First, the Americans produced a reduced number of vowels and consonants in daily conversation. The reduction rate from the dictionary transcriptions to the real transcriptions was around 38.2%. There was not much difference between the vowels and consonants in the reduction. Second, the Americans used more front high and back low vowels while 78.7% of the consonants accounted for stops, fricatives, and nasals. This indicates that the segmental inventory has nonlinear distribution in the speech corpus. From those results we conclude that there is a substantial reduction in the real speech from the dictionary symbols and suggest that English educators consider pronunciation education reflecting the real speech data.
Word-internal ambisyllabic consonants are codas
Authors: Durvasula Karthik , Huang Ho-Hsin , Merrill Rose
Published: November 2013

The syllabic affiliation of ambisyllabic consonants (e.g., the word-medial consonants in happy and Danny) is unclear. Research on ambisyllabic consonants has revealed an inconsistent set of phonetic correlates (Krakow, 1989; Turk, 1994; Gick, 2004). While some suggest they behave as onsets or codas (but not both simultaneously), others suggest their gestural durations are intermediate between onsets/codas. At least some of the research is based on comparisons of the ambisyllabic consonants to word-edge onsets/codas. However, comparisons to word-edges are confounded by the fact that such consonants undergo domain-edge related changes (Fougeron, 2001; Keating et al., 2003b). Here, we control for this confound, and compare ambisyllabic consonants to word-medial onsets and codas. We conducted an experiment on 10 native English speakers, who produced 15 repetitions at three different speech rates of 16 English words (8 test, 8 filler) that consisted of the nasal consonants [n or m] in one of four positions: word-medial onset, word-medial coda, word-final coda, and ambisyllabic context (e.g., gamete, gamble, gam, and gamma). The results suggest: (1) Consistent with previous research, there are durational differences between word-medial and word-final nasal codas; (2) Ambisyllabic consonants clearly pattern with the word-medial nasal codas and are significantly different from the nasal onsets.
The articulation of derived affrication in American English
Authors: Sung Jae-Hyun
Published: November 2013

Affrication of coronal stops before /ɹ/ is commonly observed in English. For instance, /t/ in “tree” and /d/ in “dream”, in which coronal stops precede /ɹ/, are often realized as affricated stops (i.e., [ɹi] instead of [tɹi]; [ɹim] instead of [dɹim]). Given that morphological structures and frequency of words play a critical role in many coarticulatory processes (Bush, 2001; Ernestus et al., 2006; Myers and Li, 2009), the present study investigates whether the degree of derived affrication before /ɹ/ is influenced by different morphological structures and frequency of words and phrases. This study uses ultrasound imaging and audio recordings of seven native speakers of American English to examine the articulatory aspect of derived affrication. Comparisons of the degree of affrication show significant differences among words in various environments, in which tautomorphemic words and high-frequency words and phrases lead to greater degree of affrication. Furthermore, the gestural patterns of various morphological and frequency conditions are highly individualized.
The role of the posterior cricoarytenoid muscle in phonation
Authors: Berry David , Chhetri Dinesh K. , Neubauer Juergen
Published: November 2013

The posterior cricoarytenoid muscle (PCA) is generally considered to be a respiratory muscle. Indeed, as the sole abductor of the glottis (i.e., the only laryngeal muscle with the capability of opening the true vocal folds), paralysis of the PCA may lead to asphyxiation. While the PCA muscle also appears to play a role in phonation, a consensus has not been reached among voice scientists regarding its precise role in the control of fundamental frequency, phonation threshold pressure, and other phonatory variables. Using a new developed method of graded stimulation to the laryngeal muscles, Chhetri, Neubauer, and Berry (2012) explored the role of the cricothyroid muscle (CT), thyroarytenoid muscle (TA), and the lateral cricoarytenoid and interarytenoid muscle complex (LCA + IA) on fundamental frequency, phonation threshold pressure and glottal posturing. The present study augments the previous study by also investigating the influence of the PCA muscle on these same phonatory variables. Similar to the adductor muscles, it is shown that the PCA muscle introduces new possibilities for achieving multiple phonation types at a given fundamental frequency.
Anatomic development of the hyo-laryngeal complex in humans from birth to 95 Years: An imaging study
Authors: Vorperian Houri K. , Wang Yuan , Durtschi Reid B. , Cotter Meghan M. , Kent Ray D. , Chung Moo K. , Gentry Lindell R.
Published: November 2013

During postnatal development, the hyo-laryngeal complex descends in the pharyngeal cavity primarily during early childhood, followed by a secondary descent during puberty, particularly in males. The purpose of this study is to quantify the descent of the human hyo-laryngeal complex, as well as its relational growth to other functionally related structures such as the epiglottis and the tongue from birth to 95 years. Anatomic data secured from 902 medical imaging studies (482 males; 420 females) were analyzed in two phases: (I) A detailed assessment of developmental changes of the hyo-laryngeal complex and functionally related structures from birth to 19 years using 771 imaging studies. I(I) Comparison of similar measurements between three adult groups (ages 20-to-45 years; 45–70 years, and 70–95 years) using 131 images. Findings indicate that: (a) growth/descent of the hyo-laryngeal complex is non-linear and protracted, displaying a predominantly somatic growth pattern; (b) small sex differences in growth are present during childhood, with increased differences emerging at about 10 years, and maximal differences present by 19 years; and (c) there appears to be a coincident relational growth of functionally related structures. These novel findings are of clinical significance, and enhance the understanding of vocal tract development. [NIH-Grants R01DC6282, P-30HD03352.]
Signal detection of lipreading visemes using two dimensional and three dimensional images
Authors: Quigley Rita , Yonovitz Al
Published: November 2013

The actual process by which the lipreader translates the lip movements they identify into a message is very complex. The lip movements observed represent only fragments of the complete message. The main purpose of this study is to investigate (1) the ability of lipreaders to use visual information alone to identify phonemes in varying contexts including nearby coarticulation effects and vowel neighborhoods; (2) lipreading responses using the effect of improved video presentation through 3D video, providing better and more realistic video presentation; and (3) the use of a novel measurement technique, i.e., a signal detection two-alternative-forced choice method of subject response that should provide measures of discrimination between phonemes including “visemes.” Video recordings were made in both 2D and 3D formats. This 3D image presented more realistically the movements such as lip-rounding and micro-movements of viewable articulators in three dimensions. Subjects with normal hearing were presented these video presentations. A Two-Alternative-Forced-Choice (2AFC) paradigm was used. The consonants were viewed with various vowel contexts. D-prime values were obtained for both the 2D and 3D videos. Particular consonant clusters were more discriminable in 3D.
Electropalatography examination of groove width in Russian
Authors: Howson Phil
Published: November 2013

Previous studies have indicated a difference between voiced and voiceless pairs of consonants with respect pre-constriction vocal tract volume. This article utilizes electropalatography (EPG) to examine the anterior and posterior groove width of palatalized and non-palatalized fricative pairs in Russians in order to observe different degrees of pre-constriction vocal tract volume. Measurements were taken at the point of maximum constriction using Articulate Assistant software. Higher degrees of contact with the palate were taken to indicate smaller pre-constriction vocal tract volume. The results (based on a single speaker), indicate a significant difference in the degree of contact with the palate between the voiced and voiceless pairs of non-palatalized fricatives. However, the palatalized consonants indicated no significant difference in the degree of contact with the palate. The findings suggest that the smaller vocal cavity created by the secondary articulatory gesture for palatalization is sufficient to facilitate voicing and frication; in the case of the voiced fricatives, the sub-glottal pressure is adjusted to permit vibration of the vocal cords. The findings further suggest that speakers adhere to the principle of minimal articulatory effort when producing speech.
An analysis of tongue shape during parkinsonian speech
Authors: Dawson Katherine M. , Iskarous Khalil , Whalen D. H.
Published: November 2013

Parkinson’s disease (PD) is a neurological disorder characterized by the degeneration of dopaminergic neurons. Speech impairments in PD are characterized by slowed muscle activation, muscle rigidity, variable rate, and imprecise consonant articulation. Complex muscular synergies are necessary to coordinate tongue motion for linguistic purposes. People with PD may show an altered rate of change in tongue shape during vowel to consonant transitions and may also ultimately attain less complex consonantal tongue shapes than controls during speech. In order to test this hypothesis, five PD participants, five older controls and five younger controls (all French-speaking) were imaged using ultrasound. They produced consonant–vowel–consonant word stimuli. Transitions analyzed were vowel-to-liquid (/l/) and vowel-to-velar stop. Tongue shapes were analyzed using a method designed to infer complexity by analogy with the bending energy of a thin shell [Young, Walker, and Bowie, Info. Control 25(4), 357–370 (1974)]. This method works by integrating the squared curvature of a piece-wise polynomial function fitted to the extracted discrete tongue contour. Results will be discussed in terms of shape change during the transition and maximal consonantal shape attained between PD and control subjects.
Control of voice intensity
Authors: Sjögren Karin , Ström Emmma , Lofqvist Anders
Published: November 2013

This study examined the control of voice intensity using acoustic and aerodynamic recordings. A total of 34 subjects participated half of them with and half without song training, 21 females and 13 males. The subjects produced the syllable sequence /papapa/ while the acoustic signal, the oral air flow, and the oral air pressure were recorded using the Kay-Pentax Phonatory Aerodynamic System. The oral pressure provided an estimate of the subglottal pressure. A measure of glottal flow resistance was calculated as the ratio between subglottal pressure and oral air flow.Three different voice levels were used, normal, reduced, and increased; the change between the normal level and the two others was required to be 6–10 dB. Overall, an increase in voice intensity was associated with increased subglottal pressure and glottal flow resistance with only a small increase in air flow. A comparison between the subjects with and without song training showed those with training to produce higher intensities, to use higher subglottal pressure, but lower glottal flow resistance. Female voices had lower subglottal pressure and lower flow rates but higher glottal resistance than male voices.
Menstrual cycle-dependent plasticity of auditory-vocal integration in vocal pitch production
Authors: Liu Hanjun , Zhu Xiaoxia , Niu Yang
Published: November 2013

Considerable evidence suggests that auditory function can be influenced by gonadal steroids (estradiol and progesterone), but whether there is a sex hormonal modulation of auditory-vocal integration in vocal production remains unknown. The present event-related potential (ERP) study sought to examine the behavioral and neurophysiological processing of auditory feedback during self-produced vocalization across the menstrual cycle. Eleven young Mandarin-native female speakers with regular menstrual cycle were tested during the menstrual, follicular, and luteal phases. Subjects heard their voice pitch-shifted 50 or 200 cents while producing a vowel sound /u/. Vocal compensations and ERPs in response to pitch perturbations as well as estradiol and progesterone concentrations were measured at three different phases. The behavioral findings showed significantly larger magnitude of vocal compensation at the menstrual phase in comparison to follicular or luteal phase. As to the neurophysiological findings, P2 amplitude in the luteal phase was significantly smaller compared to that in the menstrual and follicular phase. These results demonstrate the menstrual cycle-related effect on the behavioral and neurophysiological processing of auditory feedback in vocal pitch production, suggesting that the integration between auditory and vocal motor system can be modulated by the estradiol and progesterone levels across the menstrual cycle.
The high frequency environmental acoustics sediment model in the light of recent advances
Authors: Chotiros Nicholas , Isakson Marcia J.
Published: November 2013

The high frequency environmental acoustics sediment model (HFEVA) published in the High-Frequency Ocean Environmental Acoustic Models Handbook (APL-UW 9407), which has been widely adopted by underwater acousticians and sonar modelers, is examined in the light of recent sediment acoustic models and measurements, particularly the multiple scattering and poro-elastic models. The former indicates that the sound speeds and attenuations for the larger grain sizes (phi < -1) need to be updated, and the latter that the sediment densities for the middle range of grain sizes (1 < phi < 5) are underestimated. On the last point, the authors of the original model were aware of the problem, and for practical reasons decided to accept the understatement in the interests of achieving the correct reflection loss. The discrepancies may be alleviated by adopting a poro-elastic model with multiple scattering corrections. For practical applications, an efficient parameterization of the poro-elastic model allows the number of adjustable parameters to be reduced to a level comparable with that of simpler fluid and elastic models, while retaining all its physical advantages. [Work supported by the Office of Naval Research, Ocean Acoustics Program.]