bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations of phonation threshold pressure and fundamental frequency in the in vivo canine larynx using graded neuromuscular stimulation
Authors: Berry David A. , Chhetri Dinesh K. , Neubauer Juergen
Published: April 2012

Phonation threshold pressure is an objective measure of the relative ease of phonation. Previous studies of the in vivo canine larynx have reported values of phonation threshold pressure in the range of 3.5-5.5 kPa. Such studies are often cited to argue that canine and human vocal fold physiology may differ significantly, since threshold pressures in human phonation are often measured to be as low as 0.2-0.3 kPa. Similarly, the frequency range observed in canine phonation has generally been reported to be more limited than that found in human phonation. In this study, our hypothesis was that through the use of a newly-developed method of graded stimulation to both the superior laryngeal nerve and the individual branches of the recurrent laryngeal nerve, the ranges of phonation threshold pressure and fundamental frequency observed in the in vivo canine model would overlap significantly with that of human phonation. This hypothesis was confirmed. In particular, phonation threshold pressures were observed to be as low as 0.2-0.3 kPa, and the fundamental frequency range was observed to span nearly four octaves. Previous studies of in vivo canine phonation may have been limited by an inadvertent, exclusive focus on hyper-stimulation of the thyroarytenoid muscle.
Bayesian model-based filter design in acoustical signal processing applications
Authors: Botts Jonathan , Xiang Ning
Published: April 2012

Digital filter design finds applications across many disciplines. Acoustic applications include, but are not limited to, impedance boundary conditions in time-domain wave-based room-acoustics modeling, head-related transfer functions, and loudspeaker equalization. The process of filter design can be approached in a variety of ways. To design a non-standard filter, optimization methods may be used to solve for the coefficients that minimize the difference from a specified transfer function of a prescribed order. Interpreted as a model-based inference problem, a Bayesian framework, realized through the nested sampling algorithm, provides simultaneous optimal coefficient estimates and a filter order selection criterion. The selection criterion implicitly favors simpler models over more complex models, in this case lower-order filters over higher-order filters. Many acoustical applications are well suited to this type design, where low filter order is important, and the desired system response is unattainable with classical, closed-form design techniques. This paper formulates filter design problem as a problem in model-based inference. Then several illustrative examples from acoustical signal processing are used to demonstrate the flexibility of Bayesian digital filter design.
Application of time reverse mirror in underwater acoustic networks communication
Authors: Jingwei Yin , Xiao Zhang , Longxiang Guo , Xueli Sheng
Published: April 2012

Time reversal mirror (TRM) could match the acoustic channel impulse responses (CIR) automatically to achieve channel equalization without any transcendental knowledge. Active time reversal mirror (ATRM) needs monostatic sensor, and the signal propagates through the acoustic channel twice leading to inefficient. Further, the array processing enhances the complexity. In order to overcome disadvantages, the single sensor passive time reversal mirror (PTRM) and virtual time reversal mirror (VTRM) are presented. Based on the properties of underwater acoustic channel, using the uncorrelated character among different users' CIR, the single-element time reversal mirror is proposed to apply to underwater acoustic networks. The scheme could focus the desired user's information and suppress the undesired users' information. Furthermore, we have performed results of numerical simulations. Key words: time reversal mirror (TRM); channel equalization; underwater acoustic communication; networks
Own voice detection with near field head related transfer function based on frequency domain binaural model
Authors: Onoguchi Taira , Chisaki Yoshifumi , Usagawa Tsuyoshi
Published: April 2012

On the binaural hearing assistance systems with directivity control, it is difficult to distinguish user's own voice from the target speech located in front of the user. Therefore, emphasized user's own voice degrades the quality of hearing assistance. Because the own voice arrives from the specific angle in the median plane in the near field, it is difficult to distinguish whether the incoming sound is own voice or not. However, in the previous works, the elevation angle of signal source can be estimated even on median plane by means of artificial neural network based on the interaural level and phase differences. In this paper, a new method to detect own voice is proposed. This method utilizes the artificial neural network to discriminate own voice from any of signal sources located far than 1.5m from the user. The performance of this system is examined by simulation.
Study on localization of infrasound waves radiated by natural events
Authors: Lu Jun , Yang Yichun
Published: April 2012

In recent years, there happened several large earthquakes which have made very serious destruction to local people and society. Among these terrible events' gestation, occurring, and developing, infrasound waves radiated in these processes were often observed. According to the signals received by monitoring sensors, the infrasound sources should be located accurately by an infrasound microphone array. The array was constructed by several sensors of InSAS2008 developed by IACAS, distributed in the North China area. In near future, the sensors will be constructed in all China. Data of signals received by this network could be processed by some methods such as Progressive Multi Channel Correlation (PMCC), sound imaging, rainbow algorithm, etc., to get useful information of nature events. Depending upon this work, some natural events, such as earthquake, debris flow, tsunami, volcanic eruption, etc., could be forecasted under certain conditions, or get more knowledge of them.
Acoustic scattering from compact deformations of shallow-water waveguide's surfaces
Authors: An Junying , Xu Haiting
Published: April 2012

In shallow-water waveguide, compact deformations of sea surface or seafloor will affect the sound propagation. The deformations include local deformation of bottom topography, rock, trench and objects sank to the bottom, floater and surface ship on the sea surface, etc, which are all the components of an ocean waveguide. In this paper, the moments method and the boundary integral equation method are presented to compute the acoustic scattering from compact surface deformations in shallow-water waveguide. The former method combines the normal-mode theory with the numerical method for solving the boundary value problem of differential equation in local area, while the latter only covers the finite integral area of the deformed surfaces. The perturbation feature of near and far field and the deformation identification feature are analyzed.
Attenuating underwater pile driving noise at a remote receiving location using an encapsulated bubble curtain
Authors: Wochner Mark S. , Lee Kevin M. , Wilson Preston S.
Published: April 2012

Noise generated underwater by pile driving can reach dangerous levels at significant distances from the source, and thereby potentially disturb both marine life and human activities. In this presentation, we describe a method of shielding a specific underwater region remote from the source using a curtain of encapsulated bubbles. The sizes of these encapsulated bubbles are chosen so that their resonance frequencies are near the peak frequency of the noise generated by the pile driving, thus maximizing each encapsulated bubble's ability to mitigate the incoming noise through resonance phenomena. The method of using encapsulated bubbles has been previously described by the authors [J. Acoust. Soc. Am. 127:2015 (2010); J. Acoust. Soc. Am. 128:2279 (2010); J. Acoust. Soc. Am. 129:2462 (2011)], but in this work a region around the receiver, not the source, was treated with encapsulated bubbles, and the noise was due to pile driving activity rather than tonal. Results show that significant noise reduction can be attained using this encapsulated bubble curtain, in which a single layer yielded about 10 dB of SPL reduction. [Work supported by Applied Research Laboratories Internal Research and Development]
Effect of wind-generated bubble plumes on shallow water acoustic channels
Authors: Huang Xiaopeng
Published: April 2012

Wind blowing over the sea surface generates many dramatic effects. One of the most important effects is bubble plumes generated by breaking waves, which have major effects on high frequency acoustic propagation, sound speed profile and ambient noise due to the sound scattering and absorption properties of bubbles. On one hand, we will introduce several theoretical models of bubble plumes; on the other hand, we will propose how to calculate the acoustic signal attenuation and sound speed anomaly due to wind-generated bubble plumes. Simulation results will show the shallow water acoustic channel impulse response and sound speed anomaly with the effect of bubble plumes.
Near bottom acoustic and video measurements of the rise rate of methane bubbles in the Gulf of Mexico
Authors: de Moustier Christian , Boelmann Jan , Kraft Barbara
Published: April 2012

Simultaneous acoustical and optical measurements of the rise rate of methane bubbles were made at several natural seafloor seeps in the Gulf of Mexico. The measurements were taken between 2 m and 50 m from the bottom, using a remotely operated vehicle equipped with a 500 kHz multibeam sonar system capable of imaging and Doppler measurements, and a high-definition color video camera. The bubble source on the seabed at all the seeps encountered in this work was an orifice a few centimeters across that released individual bubbles at various rates. Video measurements made 3 m above the bottom showed that these bubbles formed a column 5 to 30 cm in diameter. The acoustic measurements showed that the column transitioned from laminar to turbulent flow behavior about 6 m above the bottom. Rise rates in the laminar portion are between 20 and 30 cm/s. Work funded by BP
Practice and cogitation on acoustics design of professional concert hall
Authors: Yongmin Song , Kuisheng Zhang
Published: April 2012

Development overview on design and construction of professional concert hall since the 1990s in China is summarized in this paper. Acoustics design cases of professional concert hall completed by Zhang Kuisheng acoustical design and research studio over the past decade are described. Then four designs among those professional concert halls including the architectural characteristics and acoustical parameters are introduced. Those are Hunan musical hall, concert hall in China conservatory, Beijing, philharmonic hall in Xiamen international conference center and Yangzhou musical hall. Finally, the preferred reverberation time, plane shape, volume per seat, acoustical material and diffuser design in concert hall are discussed in detail. Those successful experience and considered suggest are put forwards for sharing.
Vocal intelligibility and clarity in amplification: challenges for concert hall acoustics
Authors: Doria Damian , Clark Tom , Brooks Todd L. , McCarthy Bob
Published: April 2012

The modern concert hall presents a range of programming from soloists and small classical ensembles to large orchestras with choir. In many communities the same concert venue is also required to host a range of amplified events from politely-reinforced ensembles to overtly amplified popular music artists. Maintaining intelligibility of vocals and clarity at high amplification levels depends upon a number of factors both within the control of the acoustics and sound system designers and not. This paper will discuss the programming for a typical season at one 1600-seat concert hall, the elements within its design to allow flexibility of program use, and experiences during the process of adjustment, tuning, and optimizing the hall over its first season.
Spring isolators designed for the Melbourne Recital Centre, Melbourne, Australia
Authors: Plumb Michael
Published: April 2012

The subject matter deals with the performance of spring isolators designed to meet the specified isolation requirement for the 1000 seat Dame Elisabeth Murdoch Recital Hall located in Melbourne Australia. Predicted performance of isolators is evaluated, and measured vibration results are presented for isolated and non-isolated sections of the building. Results are presented in vibration reduction versus frequency with good agreement between predicted and achieved vibration reduction for the locations measured. Achieved background noise levels are also presented in order to provide comparison with anticipated outcomes.
Observation of blood echogenicity variation in rat arteries using high-frequency ultrasound
Authors: Nam Kweon-Ho , Yeom Eunseop , Lee Sang Joon , Paeng Dong-Guk
Published: April 2012

Previous studies have demonstrated that blood echogenicity is highly variable depending on blood flow velocity and pulsatility mainly due to the variation of red blood cell (RBC) aggregation. However, most of the studies were performed in a mock-flow loop using porcine blood and the results were not fully validated in vivo. Rat was rarely used for investigation of RBC aggregation due to its low aggregation tendency. But high-frequency ultrasound may detect the RBC aggregation from rat blood. The purpose of the present study is to investigate the cyclic and radial variation of blood echogenicty in rat arteries using a high-frequency ultrasound system with a 40-MHz scanner. B-mode images of blood were acquired from various arteries, including carotid artery and abdominal aorta. Blood echogenicity increased at systole and decreased at diastole. The cyclic variation was larger at the vessel center than near the vessel wall. The central hypoechoic zone ('black hole' phenomenon) was observed in carotid arteries. The experimental results from rat arteries in vivo corroborate the previous observations of cyclic and radial variations of blood echogenicity from porcine blood in mock-flow loops. Acknowledgments: This work was supported by the Korea Research Foundation Grant funded by the Korean Government (NRF-2011-0017984).
An optically transparent tissue mimicking phantom for monitoring the thermal lesion produced by high intensity focused ultrasound
Authors: Choi Min Joo , Guntur Sitaramanjaneya Reddy , Lee Kang IL , Paeng Dong Guk , Coleman Andrew
Published: April 2012

An optically transparent tissue mimicking (TM) phantom whose acoustic properties are close to those of tissue was constructed for visualizing therapeutic effects by high intensity focused ultrasound (HIFU). The TM phantom was designed to improve a prevalent polyacrylamide hydrogel (PAG) which attenuates ultrasound far less than a tissue and does not scatter ultrasound unlike any other tissue. A modified recipe has been proposed in the study by adding scattering glass beads with diameters of 40 ~ 80 μm (0.002 % in w/v) and by raising the concentration of acrylamide (30% in v/v). The constructed TM PAG has an acoustic impedance of 1.66 Mrayls, a speed of sound of 1,573±5 m/s, an attenuation coefficient of 0.53±0.04 dB cm-1MHz-1, a backscattering coefficient of 0.23×10-3 cm-1sr-1 MHz-1 and a nonlinear parameter (B/A) of 5.5±0.2. These parameters are close to those of liver. The thermal and optical properties are almost the same as the prevalent PAG. The TM PAG was tested to visualize the thermal lesions by HIFU and the characteristic features were contrasted with those of the prevalent PAG. In conclusion, the proposed TM PAG acoustically mimics tissue far better than the prevalent PAG and would be expected to be used in assuring if a clinical HIFU device could produce the thermal lesion as planned. Keywords: tissue mimicking phantom, high intensity focused ultrasound (HIFU), ultrasound, polyacrylamide hydrogel (PAG), monitoring, thermal lesion
Ultrasonic standing wave patterns in a petri-dish
Authors: Choi Min Joo , Kang Gwansuk , Kodama Tetsuya , Coleman Andrew J
Published: April 2012

A standing wave is well developed in a petri-dish used for cell culture, which is subject to the height of the culture fluid. A simple acoustic theory states that the pressure at the bottom of the petri-dish varies from 0 to its maximum while the height varies over a half wave length of the driving ultrasound. This suggests that the standing wave pattern should be taken into account when the cell line in a petri-dish is exposed to ultrasound. The present study has experimentally verified the theoretical prediction using the pressure sensitive film attached to the bottom of the petri-dish, when water, instead of the culture fluid, was contained in the dish. The driving field was made of 1 MHz transducer (V316, Panametrics, USA). Gradual destructuring of the standing wave patterns was observed as the driving power increased and, thus, the surface of water was becoming more fluctuating. Keywords, standing wave, petri-dish, cell, culture fluid, monitoring
Microbubble-enhanced high intensity focused ultrasound therapy: effect of exposure parameters on thermal lesion volume and temperature
Authors: Bhadane Sonal , Karshafian Raffi , Tavakkoli Jahan
Published: April 2012

Microbubble agents have been shown to increase therapeutic effect of HIFU (high intensity focused ultrasound). Here, the effects of treatment parameters on lesion volume and temperature are investigated. Ex vivo tissue was treated with a 2 MHz HIFU beam in absence and presence of the Artenga™ microbubbles at varying HIFU focal intensities (649-2316 W/cm2), microbubble concentrations, and exposure durations (3-10 s). The temperature was measured at 1 mm from focus using a K-type thermocouple. Thermal lesion volume was measured based on an ellipsoid model. Microbubbles increased the lesion volume and peak temperature achieved with HIFU. At the intensity of 2316 W/cm2, the lesion volume increased by 2-folds, and the peak temperature increased by 16° C with microbubbles. This effect depended on microbubble concentration, ultrasound intensity and exposure duration. Lower intensities and shorter time durations were required at higher microbubble concentrations to ablate the tissue. It was concluded that the efficacy of the HIFU therapy in combination with microbubbles can be controlled through ultrasound/microbubble exposure parameters
Analytical model of Dynamic AcoustoElastic Testing measurements in trabecular bone tissue: a rheological approach
Authors: Moreschi Hélène , Callé Samuel , Trarieux Chloé , Defontaine Marielle
Published: April 2012

A dynamic acoustoelastic testing (DAET) method based on the interaction of two acoustical waves was developed to measure viscoelastic properties of trabecular bone tissue. While a sinusoidal low-frequency (LF) acoustic wave successively compresses and expands the medium, ultrasonic (US) pulses are generated to probe the uniformly stressed medium (quasi-static pressure, pLF). The US pulses velocity and amplitude (c, A) vary with respect to the medium stress level. These modulations (c(pLF)-c(0); A(pLF)-A(0)) are plotted as a function of the instantaneous LF pressure. From these rheograms, nonlinear elastic and viscous (dissipative) parameters, β' and β” respectively, are extracted. Since the US velocity is directly related to the medium viscoelastic modulus (M*), considering either the celerity variations or the modulus variations as a function of LF pressure is equivalent. In this perspective, we developed an analytical model of the variations of M*, derived from the Kelvin-Voigt approach (M* as a function of pLF), introducing linear (M', M”) and nonlinear (β', β”) viscoelastic moduli. This model was first validated in water and Newtonian oils. In this paper we present preliminary results derived from measurements in the calcaneum, a highly inhomogeneous and porous trabecular bone tissue exhibiting hysteretic loops and asymmetry in rheograms.
Low frequency broadband monopole transducer based on trilaminar bender bar structures
Authors: Yuyu Dai , Xiuming Wang , Penglai Xin , Jiansheng Cong
Published: April 2012

A transducer which is produced by a skeleton and four Trilaminar bender bar vibration elements is presented in the paper. Four vibration elements formed a square array are excited by the same signal to realize monopole radiation. The influence of the skeleton is taken into account: flexural mode of vibration of the skeleton is used to extend the bandwidth. The transmitting voltage response of a modeling result shows that there are two peaks existed close to 1.8 kHz, which correspond to the 2nd order flexural mode of the Trilaminar bender bar and the 1st order flexural mode of the skeleton. The -3dB operational frequency range from 16.6kHz to 20.2kHz. The directivity patterns reflect that transducer can realize a monopole radiation in the horizontal plane before 13kHz.
Design of multi-functional ultrasonic imaging logging tool
Authors: Sun Zhifeng , Qiu Ao , Wang Wenliang , Tao Aihua , Chen Honghai , Liu Xien
Published: April 2012

By analyzing the measurement principle of the ultrasonic impulse method, a kind of Multi-functional ultrasonic imaging logging tool was designed and the implementation of its measurement technique was given. mainly contains the components of the tool, the realization of electronic sections and the measurement specifications. It can conduct borehole surface imaging in high resolution in the opened-hole. It can also conduct casing inspection and cement bonding evaluation in the cased-hole. The proposed tool was tested in the field of opened-hole and cased-hole. It shows that this tool can evaluate the geologic feature's informations, such as fracture, vug and bedding structure in the opened-hole. The casing thickness imaging, inner and outer diameter imaging and cement impedance imaging also can be measured in the cased-hole.
Study on the discrimination of the second interface bonding conditions using characteristics of the first arrivals in cased boreholes
Authors: Zhang Xiumei , Liu Xien , Chen Honghai , Lin Weijun
Published: April 2012

The evaluation of cementing bonding conditions influence the production of oil or gas in cased boreholes. Many researchers have focused their studies on identifying the cementing quality of the first and second interface, and provide lots of methods in evaluating the bonding conditions of the first interface, while for the second interface, remain a difficult problem till now. In this paper, the propagation velocity and amplitude of the first arrivals with different cement qualities, together with different channeling for the same cased hole are studied. The results show that for poor first interface bonding conditions, the velocity of the first arrival almost doesn't change with different channeling, while for poor second interface bonding conditions, the velocity varies greatly with different channeling. Specially, Time-Frequency Analysis on different cementing conditions are conducted, the analysis indicate that there is a relative large energy peak of the first arrivals for all poor first interface, while for poor second interface, which is not the case. As a result, the propagation velocity and the time frequency distributions rather than the amplitude of the first arrivals can evaluate the second interface bonding conditions.
Radial detection depths of borehole Stoneley modes
Authors: He Xiao , Wang Xiuming
Published: April 2012

Propagation features of Stoneley modes are widely used for measurements of reservoir permeability and rock anisotropy in acoustic logging. Through the finite difference algorithm, the radial detection depth of the Stoneley wave along a fluid-filled borehole is investigated. The radial variations of the displacement components Ur for Stoneley wavefronts are presented as the particle motions in that direction are controlled by the permeability and transverse shear modulus of the medium surrounding the wellbore. It is shown that the Stoneley-wave energy reaches a peak value at the borehole wall and attenuates exponentially with the increasing radial depth in the formation. By comparison of reflected Stoneley-wave amplitudes from reflectors with various distances to the borehole wall, the prospecting depths of Stoneley modes can be confirmed. It is generally no more than 0.2 meters with the frequency range of acoustic logging. This result reveals that only a very shallow region around the wellbore can be detected from the Stoneley-wave responses.
Dispersion measurement of acoustic field excited by dipole sources in fluid-filled borehole
Authors: Wang Rui-Jia , Qiao Wen-Xiao , Che Xiao-Hua
Published: April 2012

The flexural wave in fluid-filled borehole excited by dipole sources is dispersive wave. To obtain the phase slowness of dispersive waves, firstly we made several small-scaled model wells, and then measured the acoustical field excited by dipole sources. We researched three kinds of formation, including hard formation (aluminum well models), soft formation (nylon well models) and anisotropy formation (bakelite well models). For hard formation, the flexural mode is the main propagation wave mode in the measured waveforms, and the extracted dispersion curves are well agreed with theory curves. For soft formation, the measured dispersion curves do not well agree with theory curves due to the existence of stoneley wave mode. We drilled seven holes in the anisotropic media with different dip angles. This paper only studied the 7th borehole, whose axis is perpendicular to the symmetry's in this media, which is also called HTI formation model. For the HTI formation model, we observed that the dispersion curve of the slow flexural wave is obviously higher than that of fast flexural wave at the frequency plotted, which is consistent with the theory that the dispersion curves of slow and fast flexural wave arrays for intrinsic anisotropy formation are uncrossed.
Complex-modulus measurement by longitudinal vibration testing using pulse wave
Authors: Hou Hong , Sun Liang , Yang Jianhua
Published: April 2012

Paper presents a method to measure the complex modulus of rigid viscoelastic materials by the longitudinal vibration testing. In the measurement, one end of a rod of the material is driven by a transducer using a pulse wave and the other end is allowed to move freely. The Complex-modulus is calculated from the displacement ratio between the driven end and the free end. The displacement of the rod end is measured by an accelerometer whose mass load should be considered since the accelerometer is attached to the rod. The displacement ratio can be obtained over a wide frequency range because the driven signal of the pulse wave is a broadband signal. The Complex-modulus can then be determined at resonant frequencies. Some rigid viscoelastic rods are measured and the measured results agree well with that of commercial viscoelastic instrument.
Elastic wave scattering by periodic axisymmetric cavities in viscoelastic materials : theory and experiment
Authors: Bai Guofeng , Liu Bilong , Liu Ke , Sui Fusheng
Published: April 2012

The reflection, transmission and absorption performance of periodic axisymmetric cavity in viscoelastic materials are analyzed by multiple scattering(MS) method. Based on MS method of elastic wave, the transition matrix between the incident wave and scattered wave is obtained by the numerical integrals for cavity surface. Meanwhile, the complex modulus of viscoelastic materials is measured by dynamic mechanical thermal analysis and time-temerature equivalent theory. With transfer function method in water tube, the absorption coefficient curves of different specimens of rubber materials containing cylindrical cavities are obtained. The measuring results are compared with that of MS method and also verified experimentally. The results indicate energy attenuation in viscoelastic materials depends on cavity scattering properties.
A micro-machined high-Q film bulk acoustic resonator for chip-scale atomic clock
Authors: Tang Liang , Sun Quan , Qi Min , Qiao Donghai
Published: April 2012

Taking advantage of its low power consumption and small volume, Chip-Scale Atomic Clock (CSAC) will play a critical role in portable applications, underwater communication systems, unmanned aerial vehicles, underwater sensor systems and geophysical equipments. It has aroused great research interest in these years. Traditionally, the 3.4GHz Voltage Controlled Oscillator (VCO) applied to 87Rb atomic clock is based on the frequency multiplier method of a high stable crystal oscillator. It's power hungry and can not satisfy the requirement of CSAC. Based on the fact that SiO2 film can both compensate the Temperature Coefficient of Frequency (TCF) of Film Bulk Acoustic Resonator (FBAR) and improve the Q-factor of FBAR's high-order resonance, a film bulk acoustic resonator with resonant frequency 3.4GHz, Q-factor better than 500 and TCF better than 20ppm per K was designed and fabricated with a micro-machined method, which satisfied the requirement of CSAC. The authors would thank National Natural Science Foundation of China for the support under contract number 11104313.
Community response to aircraft noise around three airports in Vietnam
Authors: Nguyen Thu Lan , Nguyen Huy Quang , Nguyen Khanh Tuyen , Hukushima Hiroaki , Kawai Keiji , Yano Takashi , Nishimura Tsuyoshi , Sato Tetsumi
Published: April 2012

To assess the effect of aircraft noise on people in Vietnam, socio-acoustic surveys on community response to aircraft noise were conducted in residential areas around three airports in Ho Chi Minh City, Hanoi, and Da Nang. The community response was obtained by face-to-face interviews during the daytime on weekends. The aircraft noise was measured for seven successive days. Aircraft noise exposures ranged from 53 to 71 dB, from 48 to 61 dB, and from 52 to 64 dB Lden in Ho Chi Minh, Hanoi, and Danang, respectively. A representative dose-response relationship for aircraft annoyance in Vietnam has been proposed based on 3487 responses and noise data obtained by field measurements at 25 sites. It has been found that the curve for Vietnam is slightly higher than but rather almost consistent to the EU's curve. The respondents in each surveyed city have different levels of annoyance for the same aircraft noise exposure.
The tuning and vocal formant features of Chinese folk song singing: a case study of Hua'er music
Authors: Yang Yang , Sundberg Johan , Welch Graham , Himonides Evangelos
Published: April 2012

Hua'er music is one of the representative folk music traditions in China today, designated as part of the world intangible cultural heritage by UNESCO in 2009. Whilst folk music traditions like Hua'er have been promoted in the education of young musicians due to their musical and cultural significance, no in-depth research has analyzed the acoustic characteristics of this vocal style. In this study, studio recordings were made of eighteen folk song examples sung by four four traditional and one formally educated singers. Analyses showed that both the traditional and the formally trained singers used a tuning pattern containing four main anchor-pitches approximating a Pythagorean tuning. The voice source in two different vocal styles ('Zhensheng' and 'Jiasheng'), reportedly used by these singers in performances, were examined by inverse filtering. LTAS of songs performed by the traditional singers were similar and showed a 'Speaker's formant' cluster near 3.5kHz. Implications are drawn for the education of folk music singers in higher education.
Acoustical study of classical Peking opera singing
Authors: Sundberg Johan , Gu Lide , Huang Qiang , Huang Ping
Published: April 2012

Acoustic characteristics of classical opera singing differ considerably between the Western and the Chinese cultures. Singers in the classical Peking opera tradition are specializing on one out of a limited number of standard roles. Audio and electroglottograph signals were recorded of four performers of the Old Man roel and four performers of the Colorful Face role. Recordings were made of the singers' speech and when they sang recitatives and songs from their repertoires. Sound pressure level, fundamental frequency and spectrum characteristics were analyzed. Histograms showing the distribution of fundamental frequency showed marked peaks for the songs, suggesting a scale tone structure. Some of the intervals between these peaks were similar to those used in Western music. Vibrato rate was about 3.5 Hz, i.e., considerably slower than in Western classical singing. Spectra of vibrato-free tones contained unbroken series of harmonic partials sometimes reaching up to 17000 Hz. LTAS curves showed no trace of a singer's formant cluster. However, the Colourful Face role singers' LTAS showed a marked peak near 3300 Hz, somewhat similar to that found in Western pop music singers. The mean LTAS slope between 700 and 6000 Hz decreased by about 3 dB/octave per dB of equivalent sound level.
Abrupt register changing technique “Atari” in traditional Japanese singing
Authors: Saitou Takeshi , Sakakibara Ken-Ichi
Published: April 2012

A rapid modal-falsetto-modal register changing technique “Atari” is widely found in various Japanese traditional singing styles, such as Nagauta, Okinawan traditional singing, and Japanese traditional folk singing “Min-Yo”. In other Asian singing styles, such as Urtin doo in Mongolia and similar styles in Tyva, and Sakha, consecutive rapid modal-falsetto register change is also widely used. In this study, a vocal fold vibratory pattern of “Atari” was observed by high-speed digital imaging. In “Atari”, the vocal fold vibration did not break and was very smoothly carried out modal-falsetto and falsetto-modal register changing. Acoustical characteristics along with modal-falsetto-modal register changing were also analyzed. In “Atari”, rapid changings of F0 and spectral tilt were observed. Based on these results, synthesis methods of “Atari” using STRAIGHT were proposed. By a listening test, it was clarified that “Atari” was effectively synthesized by changing only F0 without changing any spectral parameters.
Timbral and melodic characteristics of Persian and Kurdish singing
Authors: Biglari Hama Jino , Sundberg Johan
Published: April 2012

The floridly ornamented vocal technique in the courtly heritage of the Persian singing style called Avaz was studied along with excerpts from the flamboyant variety of the vivid Kurdish tradition. Audio and EGG signals were recorded from professional male tenor singers singing stylistically typical song excerpts from each tradition. Voice source parameters and formant settings (F1 & F2) were measured from inverse filtering of the audio signal, using the custom made DeCap (Svante Granqvist) and the commercial Soundswell softwares. Fundamental frequency F0 was measured from the EGG signal using the Soundswell CORR tool. In all melismatic embellishments, melody tones were preceded by short falsetto episodes whereby F0 quickly jumped up to a peak. For example, rapid tone repetitions as well as drill-like alternations between two neighbouring scale tones were interleaved with short falsetto segments. Moreover, for most vowels, the singers tuned F1 and sometimes also F2 to a spectrum harmonic in the higher part of their voice range, i.e. above about Bb4 (235 Hz, approximately). These findings will be discussed in relation to other singing styles, such as western operatic singing.
Analysis of Chinese singing voices and its application to singing voice synthesis
Authors: Ota Kenko , Ehara Terumasa
Published: April 2012

Currently, many researchers work on singing voice synthesis in Japanese or English etc. However, there are few researches on singing voice synthesis in Chinese. Thus, this research tackles development of a fundamental frequency (F0) controlling method for realizing a natural vocal conversion system from a Chinese speaking voice to a singing voice. Firstly, Chinese singing voices are analyzed in order to clarify the characteristics of F0 contour. From the analysis result of Chinese singing voices, it has been clarified that the F0 of Chinese singing voices is varied in accordance with not only the acoustic characteristics affecting the singing voice perception, e.g. overshoot, but also the four tones. Then, vocal conversion system is developed based on findings. In order to confirm the validity of the developed F0 controlling model, the following synthesized singing voices are subjectively evaluated by native Chinese evaluators. One is synthesized by controlling F0 contour according to the musical note, the second is synthesized by considering the acoustic characteristics affecting the singing voice perception and the third is synthesized by the proposed F0 controlling method. As the result, the singing voices synthesized by the proposed method realize high naturalness.
A system for developing a series of interactive tests of vocal production requiring on-line audiovisual recording
Authors: Pan Bing-Yi , Liu Ding , Cohen Annabel J.
Published: April 2012

AIRS-TEST, an online system supporting a major collaborative research initiative, Advancing Interdisciplinary Research in Singing (AIRS), was developed. AIRS-TEST administers a sequence of interactive tests and organizes the results for analysis. The tests can present text and audiovisual information to prompt the participant's response (e.g., key presses, mouse clicks, touch-screen or audiovideo input). Researchers can design and create a sequence of related tests with auditory and/or visual stimuli via a management interface delivered by a web browser. Audiovideo recording modules can be embedded into the tests in many flexible ways. Participants need an invitation code to access a test collection. Experimental results can be explored online or downloaded for further analysis. An authority module is associated with collected data to control user's right of retrieval, considering both confidentiality and collaborative sharing. The software technologies supporting the various modules of AIRS-TEST are MySQL, Java EE, Flex and Red5. Whereas AIRS-TEST will be used worldwide to promote the AIRS study of cultural, universal, and individual influences on the acquisition of singing (Cohen et al, 2009, Annals NYAS, 1169, 112-115), AIRS-TEST can potentially support other experiments requiring on-line audio or audiovisual recording, as will be demonstrated. [Work supported by SSHRC MCRI]
Active control of noise in vehicle cabins
Authors: Pan Jie , Liu Yulan , Lu Jing , Qiu Xiaojun
Published: April 2012

Active noise control (ANC) technology has been applied to reduce low frequency noise in vehicle cabins. Different from ANC in laboratory conditions, installation of the ANC system in vehicles for a long term use requires the solution of a number of practical issues. This paper reports the progress of a couple of practical ANC installations, and the implication and solution of practical issues such as magnitude and frequency variations (corresponding to different vehicle operating conditions) of the primary and reference signals, and poor coherence between primary and reference signals.
Varying auxiliary-noise-power for improved noise reduction in active noise control systems with online secondary path modeling
Authors: Ahmed Shakeel , Akhtar Muhammad Tahir , Mitsuhashi Wataru
Published: April 2012

Active noise control (ANC) systems with online secondary path modeling (SPM) comprise two adaptive filters: 1) The FXLMS algorithm-based ANC filter to cancel the primary noise, and 2) an LMS algorithm-based online SPM filter. The online SPM filter is a supporting filter and is needed for a stable operation of the FXLMS algorithm-based ANC filter. The online SPM is achieved by injecting an auxiliary noise, which however degrades the noise reduction performance of the ANC system. In this paper, a new method is proposed for varying the power of the injected auxiliary noise in accordance with the convergence status of the power of the error signal of the SPM filter. Furthermore, in order to deal with the non-stationary noise sources, normalized step-sizes are employed for both the ANC and SPM filters. The proposed method for varying the auxiliary-noise-power achieves a good online SPM, and an improved noise reduction performance as compared with the existing methods. Furthermore, it has a reduced computational complexity as compared with the method proposed by Carini et. al. In order to verify the effectiveness of the proposed method, various scenarios of the input noise are considered in the simulation results presented in this paper.
The ISO 12913 series on soundscape: An update, May 2012
Authors: Axelsson Östen ,   ISO/TC 43/SC 1/WG 54
Published: April 2012

In February 2009 the working group ISO/TC 43/SC 1/WG 54 “Perceptual assessment of soundscape quality”, of the International Organization for Standardization (ISO), begun preparing the first International Standard on soundscape “ISO 12913-1 Acoustics — Soundscape — Part 1: Definition and conceptual framework”. This paper presents the latest version of the definition of “soundscape” and its conceptual framework. At its current state of development the framework highlights seven general concepts and their relationships: (1) sound sources, (2) acoustic environment, (3) auditory sensations, (4) interpretation of auditory sensations, (5) responses, (6) context, and (7) outcomes. By providing a standard reference, the working group aims at international consensus in order to avoid ambiguity, and to enable conceptual progress in soundscape research. ISO 12913-1 is expected to be published as an International Standard in 2015. Subsequent parts of the ISO 12913 series will deal with minimum reporting requirements in soundscape research, and methods for measuring soundscape quality.
Assessment of tranquility in an urban church garden
Authors: Jeon Jin Yong , Hwang Inhwan , Hong Jooyoung
Published: April 2012

Tranquility in view of urban church soundscape was assessed by field measurements and soundwalks. The Cathedral Myeong-dong located in the heart of Seoul was selected as a measurement site. Five sites adjacent to the church buildings were selected for field measurements and audio recordings were conducted at the sites. From the field measurements, the temporal and frequency characteristics, and several acoustic parameters of the sound environment at each site were analyzed. In addition, a general questionnaire survey was conducted to identify people's perception on the current church soundscape and design elements to enhance the spaces. Individual soundwalks were also performed in order to evaluate soundscape perception in the church garden. From the results, the indicators representing tranquility sensation in urban church garden were investigated.
The influence of thresholding passive bubble-acoustic signals on the quantification of physical effects
Authors: Manasseh Richard , Zhu Yonggang , Chanson Hubert , Ooi Andrew , Babanin Alexander , Bobevski Irena
Published: April 2012

Passive emissions of sound by bubbles provide potentially useful data in many natural and engineered systems. Bubble-acoustic data are used to predict the severity of volcanic eruptions, identify undersea gas seeps, and measure ocean wave breaking. In these natural cases, and in many chemical engineering and metallurgical processes, statistics on the bubble size are sought; the bubble size controls the rate of gas to liquid mass transfer as well as fluid dynamical aspects such as mixing. However, owing to uncertainty in the physics generating the acoustic amplitude, bubble-size determination remain essentially empirical, requiring an threshold to select data. The impact of various thresholding and data-windowing techniques is discussed. Examples are given on the data from a chemical engineering aerator, a plunging jet, and a case in which diagnostic statistics can be used to identify the threshold giving the optimum sensitivity and specificity for detecting the breaking of wind-waves. Once found, the optimum threshold can be used to infer relevant physics from the acoustic signal alone.
Spatiotemporal quantification of therapeutically relevant cavitation for ablation and drug delivery by ultrasound
Authors: Coussios Constantin-C. , Jensen Carl , Ritchie Rob , Gyongy Miklos , Hockham Natalie , Rifai Bassel , Mylonopoulou Eleonora , Choi James , Collin Jamie R.T.
Published: April 2012

Stable and inertial cavitation have been shown to play a key role in several therapeutic ultrasound applications, ranging from non-invasive ablation to drug delivery. In order to achieve meaningful quantification of therapeutically relevant cavitation, a hypothesis as to the underlying mechanism by which bubbles enhance energy delivery and momentum transfer to their surroundings must first be formulated. Based on this hypothesis, correlations can be sought between time-based or frequency-based metrics of a relevant cavitation 'dose' and the desirable associated bioeffects, enabling the establishment of thresholds for therapeutically relevant processes to occur. However, the problem is complicated further by the fact that a single type of cavitation activity rarely occurs throughout an ultrasound exposure, or throughout the acoustic field of a therapeutic transducer. A recently developed method, known as passive acoustic mapping, makes it possible to obtain real-time maps of inertial and stable cavitation activity and could thus enable improved dosimetry of therapeutically relevant cavitational processes. The use of passive acoustic mapping for spatiotemporal classification and quantification of cavitation will be illustrated in the context of HIFU ablation, drug release from thermosensitive liposomes and drug delivery.
Effect of microbubble-induced microstreaming on the sonoporation
Authors: Zhang Dong , Tu Juan
Published: April 2012

In the present work, MCF-7 cells mixed with polyethylenimine: Deoxyribonucleic acid (DNA) complex and microbubbles were exposed to 1-MHz ultrasound with low acoustic driving pressures (0.05-0.3 MPa). The sonoporation pores generated on the cell membrane were examined with scanning electron microscopy. The results show that larger sonoporation pores would be generated with the increasing acoustic pressure or longer treatment time, which could be useful for the enhancement of DNA transfection efficiency, the mean diameters of pores ranged from 100nm to 1.25 μm. The calculated results based on Marmottant model indicate that the microstreaming-induced shear stress might be involved in the mechanisms of the low-intensity ultrasound induced sonoporation. [This work is supported by the National Basic Research Program 973 (Grant No. 2011CB707900) from Ministry of Science and Technology, China, National Natural Science Foundation of China (11174141), and the Fundamental Research Funds for the Central Universities (Grant Nos. 1103020402, 1116020410 and 1112020401)]
Quantification of bubble population in bubbly liquids
Authors: Ohm Won-Suk
Published: April 2012

Estimation of bubble spectra is usually performed through the inversion of attenuation and/or dispersion measurements of bubbly liquids [see, for example, Commander and Prosperetti, J. Acoust. Soc. Am. 85, 732-746 (1989)]. However, the inversion method often fails to yield accurate bubble spectra, as the bubble resonance starts to play a significant role. An alternative approach is to infer the bubble population from the sound of Minnaert-like bubble oscillations within the bubble cloud [Leighton and Walton, Eur. J. Phys. 8, 98-104 (1987)]. In this talk, a survey of the existing methods for bubble spectrum estimation is given with a particular emphasis on the pros and cons of each method under different circumstances.