bluuebunny/crossref_metadata_2025 huggingface dataset:
Direction-of-arrival estimation using a three-dimensional cross array equipped underwater glider
Authors: Jiang Yong-Min
Published: November 2016

With the development of autonomous platform and sensor technologies, unmanned underwater vehicles have been more and more involved in maritime intelligent surveillance and reconnaissance missions. The NATO—STO—CMRE has been exploring the capabilities of gliders for monitoring underwater environment by means of passive acoustic sensing. During the CMRE GLISTEN’15 sea trial, an eight-element, three dimensional cross array equipped Webb Slocum glider was deployed to study its capability of providing the direction of arrival (DOA) estimation of the signal of interest. Continuous wave pulses at multiple frequencies (300—1000 Hz) were transmitted by an acoustic source. The 3D array equipped glider was programmed to glider along a helix curve in the vicinity of the acoustic source. The DOA capability of the glider using the acoustic data collected by the acoustic payload, along with the glider pitch-roll-heading, and position information is evaluated in this study. [Work funded by NATO-Allied Command Transformation.]
A synthesized boundary condition for wave-based room acoustics simulations using ensemble averaged impedance measured in-situ
Authors: Otsuru Toru , Tomiku Reiji , Okamoto Noriko , Saigo Sakura , Yamauchi Saki
Published: November 2016

The importance of wave-based room acoustics simulation has been increasing in various fields of researches and design-stages. The problem remained, however, is how to model the rooms’ absorptive boundary conditions. It is known that traditional absorption indices like sound absorption coefficient and normal impedance are not always suit for such a fine method like finite element method. Then, the concept and measurement technique of ensemble averaged impedance were presented. In our previous studies, a series of in-situ measurement of ensemble averaged impedances were successfully performed to result excellent reproducibility and repeatability. Herein, the outline of the concept of ensemble averaged impedance including the measurement technique is summarized, first. Second, several example results of practical measurements are given to exhibit that their uncertainties stay within the range for wave-based simulations to keep their resulting uncertainties less than just noticeable difference. Then, a mathematical-physical model of synthesized boundary condition is given using the ensemble averaged impedance in the sound field analysis by finite element method. Finally, the results of sound field simulations of realistic rooms are shown to examine the plausibility of the model.
Finite-difference time-domain analysis in porous materials by using Z-transform theory and infinite impulse response filter design
Authors: Zhao Jing , Lee Hyojin , Sakamoto Shinichi
Published: November 2016

Porous materials are wildly used to control noise in various places. When simulating sound field containing porous materials by Finite-difference time-domain (FDTD) method, it is necessary to develop FDTD formulations in the porous materials. When the frame of the porous material is motionless, the porous material can be replaced on the macroscopic scale by an equivalent fluid. Based on the equivalent fluid model, FDTD formulations in the porous material are developed. The method combines IIR (Infinite impulse response) filter design and Z transform theory. The effective bulk modulus and the effective density of the porous material are frequency dependant, which is designed as IIR filter. Wave equations with IIR filter modeled parameters are solved in Z domain to avoid troublesome convolution integrals in the time domain. At the Z domain, new parameters are assumed to simplify the wave equations. Finally, wave equations and assumed parameters are returned back to the time domain. The accuracy of the proposed method is verified with the measurement. As two application examples, porous material coved with permeable membrane or non-permeable membrane are simulated and compared with the theory.
Signal processing method for compensating air absorption and phase change in room impulse response
Authors: Koyanagi Shinichiro
Published: November 2016

It is often required to remove an influence of air absorption effect from a measured impulse response (e.g., absorption coefficient measurements by a reverberation room method). In particular, a room acoustic test in a scale model is greatly influenced by the air absorption and most of the attenuation of the observed impulse response is caused by air absorption, because the test measurement must be carried out in a high-frequency region including ultrasonic band in order to cover a wide frequency audible range in the real scale. Therefore, a high-accuracy compensation technique is needed so as to correctly evaluate the scale model responses. So far, two methods have been proposed, which utilize a subband division or a time-varying filter. In this study, we propose a new signal processing technique to remove the air-absorption effect by using a propagation distance distribution function obtained from the impulse response and a propagation constant. Some practical application results are presented and show that our proposed method can be performed with high accuracy and overcome some disadvantages of the existing methods.
The influence of hearing and seeing on aesthetic judgments of performance spaces
Authors: Maempel Hans-Joachim , Horn Michael
Published: November 2016

The perception of rooms involves different modalities, particularly hearing and seeing. Fundamental questions of audio-visual room perception have, however, not been answered yet. We investigated to what extent aesthetic judgments on music and speech performances in different spaces are based on hearing, seeing, and their interaction. Meeting methodological criteria such as optoacoustic commensurability and optoacoustic dissociation, and applying a data-based, three-dimensional, high-resolution optoacoustic simulation providing nearly all perceptually relevant physical cues allowed for a valid proportionate quantification of these shares for the first time. BRIRs and panoramic stereoscopic images were acquired in six rooms. Recordings of both a music and a speech performance were put in the rooms by applying dynamic binaural synthesis and chroma-key compositing. The scenes were played back by the use of a linearized extraaural headset and a semi-panoramic stereoscopic projection system. Test participants were asked to rate the pleasantness, powerfulness, and excitingness of the performance, their spatial presence in the virtual scene, and the matching of the acoustical and the optical room. Statistical analyses indicate among others, that the aesthetic judgments mainly relied on acoustic information, whereas the presence and the matching judgment was mainly influenced by the interaction of optical and acoustical room properties.
The use and mis-use of reactive systems in the design of performance halls
Authors: Talaske Richard , Hamilton Scott
Published: November 2016

While the “surface of infinite impedance” or “totally absorptive material” makes our acoustic theories understandable and our analytical calculation methods useful, more often than not such conditions are not met in built performance facilities. Since the materiality of a performance hall strongly influences the quality of sound within a space, the physical reality of the reactive impedance of building elements must be managed to achieve quality sound. This paper discusses the practical application of various room acoustic design options, including wall and ceiling material choices, and offers comment on how various reactive systems within performance halls can detract from a room and/or reintroduce sound energy into a space. Discussion will occur regarding how such conditions can be either favorable or detrimental to the aural environment. Examples will be offered which suggest a reactive room surface can offer favorable room acoustic results for impulsive sound events, and unfavorable results with sustained sound events. Observations and subsequent testing suggest that the ability to discern the impact of reactive systems within a hall depends upon the test methods implemented during acoustic measurement sessions.
Autonomous optimal location of articulation materials using robotics
Authors: Uehara Masashi , Kawai Shuhei , Okawa Shigeki , Fukushima Manabu
Published: November 2016

We developed an application that determines optimal places of a robot equipped with articulation materials to improve sound environment. Lots of acoustic devices that incorporated architectural acoustics technology have been developed (e.g., articulation material, sound-absorbing material, etc.). In many cases, those materials are placed at positions that are effective by professional people. Our purpose is to make an autonomous robot to decide the material's position instead of professionals. We chose “Aural Sonic,” the articulation materials to be mounted on the robot. “Aural Sonic” is one of the acoustic devices that is expected effects to improve the hearing. This robot can change the position and angle little by little, to measure the impulse response each time. The application extracts the acoustic features corresponding to the speech clarity from the measured impulse response and calculates the evaluation value. The robot, which gives the position with high evaluation value, could be used for the articulation materials more effectively. We introduce the system that finds the optimal location of the articulation material with the robot.
Interaction of gain-control mechanisms in the sonar of odontocetes
Authors: Supin Alexander , Nachtigall Paul E.
Published: November 2016

The sonar of odontocetes processes echo signals within a wide range of echo levels. The level of echoes varies by tens of dB depending on the the target strength, the distance to the target, and the sound absorption by the media. The sonar of odontocetes has several mechanisms to compensate for the echo-level variation (gain control): (i) variation of emitted sonar pulse levels (the longer the distance to the target, the higher the level of the emitted pulse), (ii) short-term variation of hearing sensitivity based on forward masking of the echo by the preceding self-heard emitted pulse and subsequent release from the masking, and (iii) long-term active control of hearing sensitivity. These three mechanisms not just add to one another but act coordinately and form a united system of gain control. In particular, an increase in the sonar pulse level prolongs the distance of action of the forward-masking mechanisms. Active variation of hearing sensitivity makes the range of action of the forward-masking mechanism fitting the particular target distance and strength. These interactions of the gain-control mechanisms makes the auditory system capable of effectively analysis of echoes within a wide range of target strengths and distances.
Experimental audible sonar to model echolocation by the blind
Authors: Kuc Roman B. , Kuc Victor B.
Published: November 2016

Some blind humans echolocate by emitting palatal clicks and processing echoes, even when there is temporal emission/echo overlap (EEO). Our previous work indicates that high frequencies in the emission that travel directly to the ears are attenuated and, when high frequencies are heard, they come from target echoes. Binaural processing of these high frequency components in the EEO signals provide target range and bearing. Our experiments with 3D-printed parabolic pinnae and a speaker emitter indicate that while the high frequency components are important for object classification, the low frequencies in the emission provide more robust bearing localization because pinna diffraction effects are reduced. Classifying targets with EEO signals requires analysis in the power spectral domain because of the phase insensitivity of hearing. The power spectrum Fourier inverse estimates the autocorrelation function of the target reflector sequence. Robust autocorrelation estimates occur when the emission and echo contain comparable energies. Our experiments demonstrate that the echo energy varies with target type (e.g., planar or cylindrical) and the optimum range for classification depends on the target and itself forms a target classification feature.
IRAP: An integrated, real-time, autonomous passive acoustic monitoring system for beaked whale detection, localization, and tracking
Authors: Premus Vince , Abbot Philip , Gedney Charles , Christman Russ , Helfrick Mark , Campbell Richard , Douglas Kim
Published: November 2016

The integration and demonstration of passive sonar hydrophone arrays into autonomous undersea platforms for acoustic marine mammal monitoring has witnessed significant advances in the last few years due to the availability and scalability of low-cost, low-power commercial technology for acoustic remote sensing. In this paper, we will review the at-sea performance of a nine-element Mills Cross high frequency hydrophone array (HFA) integrated into an autonomous undersea vehicle (AUV) for the detection, classification, localization, and tracking (DCLT) of beaked whales during a deployment conducted off leeward Kauai in February, 2016. Using passive sonar equation analysis, we will review the design rationale of the HFA, and quantify system performance using standard signal processing metrics such as measured array gain, tracking accuracy, and detection range on a calibrated high-frequency source transmitting replica beaked whale click trains at a de minimus source level. A candidate autonomous real-time passive sonar processing architecture that combines an adaptive beamformer/matched filter front-end with a false alarm mitigation back-end to balance detection sensitivity, classifier robustness, and processing throughput will also be presented. We conclude with a cost/power/persistence trade-off for some commercially available autonomous platforms. [This work was supported by NAVFAC Living Marine Resources Program.]
A system for acoustic detection, classification, and localization of terrestrial animals in remote locations
Authors: Hawthorne Dean L. , Horn William , Reinke Danny C.
Published: November 2016

Acoustic monitoring of endangered terrestrial animals often involves deploying observation equipment to remote locations which may be difficult or hazardous for human observers to access. We present a system designed for deployment to such locations which is capable of detecting, classifying, and localizing a wide range of vocalizations. The battery/solar powered system can continuously record data for two weeks while sending real-time Wi-Fi detection alerts. Normally, three systems, each composed of a sensor array consisting of a 16 element microphone array, an ancillary processor box, plus ancillary equipment as needed, are deployed allowing detection geolocation. The computer system uses a computationally efficient beamforming algorithm to achieve 12 dB of gain and locate detections in both azimuth and elevation. Vocalizations are classified using a template matching algorithm in the spectrogram image domain. Localization is achieved by crossing the far-field bearings obtained from the three beamformers. Output is integrated into Cornell’s Raven Pro software package. Experimental trials with endangered Mojave Ground Squirrel vocalizations have resulted in successful detection and bearing estimation. [Work sponsored by Air Force SBIR AF112-193 currently in Phase II.]
A generic system for the automatic extraction of narrowband signals in underwater audio
Authors: Madhusudhana Shyam , Gavrilov Alexander , Erbe Christine
Published: November 2016

Narrowband acoustic signals occur prominently in underwater environments and are commonly used to monitor or track the sources producing them. Disparate ad hoc systems have previously been developed for the detection or recognition of several forms of narrowband signals produced by specific sources. We present a generic system, based on post-processing of spectrograms, for the automatic extraction of time-frequency contours of narrowband signals produced by any source—biological, anthropogenic, or geophysical. A two-phase approach is proposed where the first phase is based on an image-processing technique for detecting intensity ridges and the second phase is a Bayesian filtering approach for tracing the trajectory of detected ridge apices. The choice of algorithm parameters and conditionals are backed with theoretical motivations and are geared to result in a generic (non-targeted) system. In comparison to an existing method, using publicly available pre-annotated recordings containing four species of dolphins, our system offered improvements of 21% and 15% in precision and recall rates, respectively. A streaming-mode implementation in Matlab processed inputs with an average real-time factor of 0.10 on a modest desktop computer, showing that the system is well-suited for both offline and in-situapplications.
The application of coastal acoustic tomography to a large experimental wave/current basin
Authors: Li Guangming , Ingram David , Kaneko Arata , Gohda Noriaki , Polydorides Nick
Published: November 2016

This article describes the use of acoustic tomography to characterize the flow pattern in the Flowave basin. Flowave is a unique circular wave/current basin, 2 m deep and 25 m in diameter. Current can be created in any direction at speed of up to 1.2 ms.-1. Two coastal acoustic tomography (CAT) stations were used operating at 50 kHz with a M- sequence signal. By combining three different pairs of station positions and seven current directions a network of seven CAT stations has been emulated. Throughout the test, a current speed of 0.8 ms-1 was used. Using the inverse Fourier method, a velocity profile has been obtained. During the experiment, a Nortek vectrino velocimetry was placed between the stations. This paper will present the comparison between the vectrino and CAT measurement.
A framework for providing real-time feedback of environmental noise levels over large areas
Authors: Nykaza Edward T. , White Michael J. , Barr Jesse M. , Blevins Matthew G. , Bunkley Steven L. , Wayant Nicole M. , Wilson D. Keith
Published: November 2016

Environmental noise can cause sleep disturbance, annoyance, complaints, and quite possibly adverse health effects. This is true for continuous noise sources such as steady road traffic noise, impulsive noise sources such as blasts or sonic booms, or sources that fall in-between such as intermittent train and aircraft noise. One way to manage environmental noise is to use noise-monitoring technology to provide both the noise-producers and noise-experiencers feedback on the actual noise environment. Traditional noise-monitoring systems, however, only provide this information at a few locations resulting in an incomplete picture of the noise environment over the entire regions of interest. In this paper, we discuss a framework for providing real-time feedback of the noise environment over a large area (e.g., 100 km2). We show all the steps that are needed to convert the raw noise-monitor data into noise maps and noise impact maps to help manage environmental noise. We discuss the complexity of the problem and present several different ways to visualize the data.
Sociophonetic analysis of vowel variation in African American English in the Southern United States
Authors: Holt Yolanda F.
Published: November 2016

Sociophonetic analysis is a quantitative method used to measure the dynamic acoustic properties of speech. Sociophonetic analysis pairs the demographic, geographic, and sociopolitical components of sociolinguistic inquiry with instrumental phonetic measurement techniques. This paper applies sociophonetic analysis to the study of regional vowel variation in African American English. Previous research has established robust variation in White American English. Only recently have explorations of dialect variation in African American English been completed. Analyses of vowel space area, vowel fronting, raising, and vowel dispersion reveal both regional alignment and racial/ethnic alignment of vowels produced by African American English speakers in the Southern United States. Regional variation in vowel production in African American English is observed. Findings are discussed with respect to the Southern Vowel Shift, the hypothesized African American vowel system and a proposed omniscient observer effect that directly impacts vowel production in African American English speakers in the United States. The impact of these findings is discussed for their importance in the analysis of theories of speech production and communication.
Cross-modal association between auditory and visual-spatial information in Mandarin tone perception
Authors: Hannah Beverly , Wang Yue , Jongman Allard , Sereno Joan A.
Published: November 2016

Speech perception involves multiple input modalities. Research has indicated that perceivers may establish a cross-modal association between auditory and visual-spatial events to aid perception. Such intermodal relations can be particularly beneficial for non-native perceivers who need additional resources to process challenging new sounds. This study examines how co-speech hand gestures mimicking pitch contours in space affect non-native Mandarin tone perception. Native English as well as Mandarin perceivers identified tones with either congruent or incongruent auditory-facial and gestural (AF/G) input. Perceivers also identified congruent and incongruent auditory-facial (A/F) stimuli. Native Mandarin results showed the expected ceiling-level performance in the congruent A/F and AF/G conditions. In the incongruent conditions, while A/F identification was primarily auditory-based, AF/G identification was partially based on gestures, demonstrating the use of gestures as valid cues in tone identification. The English perceivers’ performance was poor in the congruent A/F condition, but improved significantly in AF/G. While the incongruent A/F identification showed some reliance on facial information, incongruent AF/G identification relied more on gestural than auditory-facial information. These results indicate positive effects of facial and especially gestural input on non-native tone perception, suggesting that cross-modal (visual-spatial) resources can be recruited to aid auditory perception when phonetic demands are high.
Sound absorption of Helmholtz resonators included a neck extension built in surface panel
Authors: Nakanishi Shinsuke
Published: November 2016

Acoustic resonant absorber like a perforated panel or a Helmholtz resonator can be tuned at a low frequency by extending its neck or enlarging cavity volume. However, a total size of the resonators is often quite large when the neck or the cavity is simply extended for tuning at a low frequency. Previous researchers have studied Helmholtz resonator shortened in its size by subsided neck into back air cavity, and confirm that this resonator is tuned at low frequency without a deep cavity. The author has studied the effects of a winding built-in neck extension to sound absorption of perforated panels, which shows same effects as the subsided neck into back cavity. This study obtains sound absorption coefficient by measuring surface acoustic impedance at Helmholtz resonator, and discusses sound absorption of the resonator included various neck extensions built in a surface panel. Discussions in this paper focus effects of path length, patterns, or number of turns of the winding neck extension and cavity volume to the sound absorption of the Helmholtz resonator.
Evaluation of dependence on calculation parameters in interface settings for finite-difference time-domain analyses of acoustic fields
Authors: Ogawa Chihiro , Okubo Kan , Tsuchiya Takao
Published: November 2016

To date, numerical analysis for sound wave propagation in time domain has been investigated widely as a result of advances in computer technology. The finite difference time domain (FDTD) methods are very widely used for time domain numerical analysis. The following is a family of FDTD method, for example, the standard FDTD method based on Yee’s algorithm, wave equation FDTD (WE-FDTD) method, the FDTD(2,4) method, and so on. The FDTD and WE-FDTD methods cause numerical dispersion error due to using second order finite difference (FD) approximation. To overcome this problem, the FDTD(2,4) method using higher order spatial FDs have been proposed. On the other hand, the settings of the interface between different media are important issue to solve acoustic wave propagation in non-uniform media. In this study, we examine the dependence on calculation parameters in the settings of interface for some FDTD methods. The present study shows dependence on the CFL number and ratio of sound velocity and impedance between the boundaries. We demonstrate that accuracy of the interface between different media strongly depend on calculation parameters and the ratio of sound velocity. Moreover, the proposal settings of the interface for the FDTD(2,4) methods are more accurate.
Effects of meaningful or meaningless noise on psychological impression for annoyance and selective attention to stimuli during intellectual task
Authors: Tamesue Takahiro , Saeki Tetsuro
Published: November 2016

The presence of noise during the performance of cognitive task, commonly causes a subjective experience of annoyance, which can lead to a decline in performance. This tendency is stronger for meaningful noise such as a conversation than for meaningless noise such as heating, ventilating, and air-conditioning noise. This paper first focus on the degree of meaningfulness of noise, then discuss the psychological impression of annoyance during auditory or visual cognitive tasks under the meaningful noise or meaningless noise. In addition, we considered how the brain responds on transient event-related potentials (ERPs), elicited by external auditory or visual stimuli, can be measured using electroencephalography (EEG). The present experiment was designed to determine the effects of meaningfulness of the noise on selective attention to stimuli under the odd-ball paradigm. To this end, we examined differences in the N100 and P300 ERPs of these components. The principal component analysis (PCA) was adopted to define a set of components. Our results suggested that degree of meaningfulness of noise has a strong influence on not only the psychological impression of annoyance but also the selective attention to stimuli in cognitive tasks.
Interindividual differences in directional loudness
Authors: Meunier Sabine , Savel Sophie , Chatron Jacques , Rabau Guy
Published: November 2016

Sensibility of loudness to sound direction was measured in a two-intervals, 2AFC interleaved-adaptive procedure. We measured the level (at the center of the listener head) of a test sound matching the loudness of a reference fixed at 0° and 65 dB SPL (at the center of the listener head). Azimuths of the test sound varied from 0 to 180° by steps of 15°. Elevations were 15°, 30°, 45°, 60°, and 90°. Both test and reference sounds were wide-band noise. The difference between the levels of reference and test sounds at the point of loudness equality defined the Directional Loudness Sensibility (DLS). A group of 24 listeners showed up large differences in DLS. For the majority, the highest DLSs were around -4 dB. For a few of them DLSs were as large as -9 dB. Some listeners did not exhibit any DLS and could even achieve positive DLSs. The sound pressure levels, measured at the entrance of the ear canal, were related to the DLSs to see whether the interindividual differences in DLS were exclusively due to the filtering by the head or if extra-acoustics factors (such as binaural loudness constancy) might be involved in directional loudness sensitivity.
Audio quality in everyday listening situations
Authors: Oehler Michael , Wildenburg Thomas , Reuter Christoph
Published: November 2016

The quality of digital audio which uses a form of lossy data compression is in the focus of several studies. The experimental focus of these studies includes the fundamental difference between objective and subjective measurement methods (Pocta & Beerends, 2015), test standards (Breebaart, 2015), or signal processing (Khaldi et al., 2013; Jung et al., 2016). But there are only few studies concerning the impact of perceived quality differences in everyday listening situations (ELS). Short excerpts of recent popular music recordings were encoded with different bit rates based on codecs that are commonly used by popular music streaming services. While the encoded files were presented via standard Samsung in-ear headphones, the everyday listening situation was simulated by using binaural recordings of a shopping mall soundscape that was simultaneously presented via Stax electrostatic headphones. In a control condition no soundscape was used. The stimuli were rated by 30 participants in a MUSHRA listening test (ITU-R BS.1534). A repeated measures ANOVA showed that there are significant differences for both conditions concerning the different stimuli (ELS: F(10,20) = 25.237, p = .0001, μ² = .927; no ELS: F(10,20) = 51.073, p = .0001, μ² = .962), but the effect sizes are consistently smaller in the condition with simulated everyday listening situation. The difference between both conditions gets smaller, the lower the bit rates are. A follow-up study additionally includes binaural audio that is currently used by radio stations.
A study of a voice evacuation guidance system using a precedence effect
Authors: Hashimoto Miyu , Osumi Ayumu , Ito Youichi
Published: November 2016

We have developed a voice evacuation guidance system using a precedence effect when a fire breaks out in a building in order to guide refugees to safe place efficiently. This system has already applied to an underground shopping center which has a space like a straight path as an aggressive evacuation guidance system. Further, a method for adapting this system to large interior space is examined and the effectiveness of this system have been identified basically. As a goal of this research, it was intended to develop a highly accurate acoustic design method for designing the voice evacuation guidance system. For realizing this, it is necessary to clarify relationship between acoustic conditions and a sound direction recognition in this system and create a database of these relationship. In this report, as one of important factors of developing this system, we performed an experimental measurement in relation to a recognition time of a composed sound by a preceding sound and a secondary sound. It was studied in particular detail for the secondary sound coming from various angles relative to the preceding sound.
Characterizing real-world auditory scenes using 360° audio-visual capture
Authors: Foots Ashley , Dickerson Kelly , Gaston Jeremy
Published: November 2016

Accurate sound identification is a critical aspect of situational awareness. Environmental sound identification is influenced by physical stimulus dimensions and subjective factors, such as pleasantness or familiarity. Ecological frequency, the prevalence of sounds’ occurrences in the environment, may also play an important role; however, accurately capturing this information for real-world sounds is difficult. Due to limited information about ecological frequency and the difficulty of accurately characterizing acoustic characteristics of real-world sounds studies do not typically account for this information during stimulus selection. The present study evaluates ecological frequency for environmental sounds collected using a RealSpace Camera, a spherical array of 64 microphones and 5 HD cameras. Environmental sound recordings were captured in various urban and rural settings. Samples were recorded for 30 seconds at five to ten minute intervals for one hour (resulting in up to six samples per session). These multichannel, short-interval recordings were augmented by hour-long single channel samples to enable comparison between long and short term spectro-temporal changes associated with the captured scenes. Human raters then evaluated recorded scenes with and without video confirmation to estimate ecological frequency. This effort is the first step in characterizing the real-world sensory environment and its influence on perceptual performance.
A high-resolution head-related transfer function dataset and 3D ear model database
Authors: Fels Janina , Bomhardt Ramona
Published: November 2016

Binaural reproduction techniques, which use head-related transfer functions (HRTFs), become more and more popular. Human localization performance using binaural synthesis is, however, often poor due to non-individual HRTFs. To investigate the physical relationship between the ear geometry and the directional HRTFs, the ears and the HRTF datasets of 48 subjects are measured. The detailed ear models are obtained from magnetic resonance imaging scans of the subjects. Two rough scans series of the head and a detailed horizontal scan series, which covers both ears, are taken. The 3D model meshes, which are generated from the MRI scans, allow a very precise determination of anthropometric dimensions which can be used for the individualization of the HRTFs. Additionally, the relationship between the anthropometric dimensions and monaural cues of the HRTFs is studied by the boundary element method. These simulations show which parts of the pinna are involved in case of resonances or destructive interferences.
Individualization of head-related transfer functions by the principle component analysis based on anthropometric measurements
Authors: Bomhardt Ramona , Fels Janina
Published: November 2016

A binaural reproduction either uses individual or generic head-related functions (HRTFs). The assessment of individual spatial high-resolution HRTF datasets is very time-consuming and requires a special measurement setup. On the other hand, a generic HRTF dataset from a dummy head can lead to localization errors such as front-back confusions and in-head localizations. In the present work, the generation of individualized HRTF datasets using the principle component analysis and multiple regression analysis from a generic HRTF dataset is discussed. The individualized HRTFs reduce the localization errors by taking individual anthropometric dimensions of the head and pinna into account. The method is applied to 48 individual HRTF datasets to determine the principal components and their weights. The anthropometric dimensions are obtained from the 3D magnetic resonance imaging scans of the 48 subjects. The focus of the work is on the number of necessary principle components with respect to the measurement grid and redundancy of anthropometric dimensions.
Effect of characteristics compensation between air-conduction and bone-conduction headphones on sound localization in an anechoic chamber
Authors: Ogiso Satoki , Mizutani Koichi , Wakatsuki Naoto , Zempo Keiichi , Maeda Yuka
Published: November 2016

Bone-conduction (BC) headphones are used when users need to hear provided sounds as well as environmental sounds since they do not occlude the environmental sounds. Sound localization characteristics of the BC sounds are usually worse than that of the air-conduction (AC) sounds. If the frequency characteristics of AC sounds can be reproduced with BC headphones, better sound localization with BC headphones can be achieved. To compensate the frequency characteristics difference between these sounds, a method to measure the frequency characteristics difference is proposed. Also, compensated BC sound is examined by localizing sounds. At first, the difference between AC and BC sounds are measured by tuning their amplitudes and phases to cancel at perceiving sound. The measurements were conducted for 30 frequencies in the audible range. Second, localization characteristics are measured in an anechoic chamber. The sounds are presented from AC and BC headphones using the corresponding head related transfer functions in the horizontal plane. Especially for the BC headphone, the characteristics difference between AC and BC are compensated. Based on single-user experiment, characteristic peaks were confirmed in the frequency characteristics difference. The more detailed experimental results with multiple number of users and discussions will also be provided.
Simulation of frequency characteristics of bone conduction by own speech
Authors: Nakai Takayoshi , Suzuki Kenta
Published: November 2016

When a speaker himself/herself hear his/her own speech, it is different from recorded speech. It is known that it is due to bone conduction. But we measured sound at the entrance of the ear, and it is shown that speech heard by speaker himself/herself is almost agreement with sound at the entrance of the ear at more than 1 kHz. This time, we simulate frequency characteristics of bone conduction. The vocal tract have loss factor of air viscosity and heat conduction of the wall, and it is assumed that the ear drum is vibrated by vibration of the vocal tract. These results are reported.
Psychophysical investigation of binaural spatial-audio music perception with varying degrees of realism
Authors: Jin Craig T. , Epain Nicolas , Zhu Mengyao
Published: November 2016

A psychoacoustic listening test is conducted to explore the influence of varying degrees of realism on binaural spatial-audio music perception. The specific factors that are varied in combination are: (1) whether or not head-tracking is used; (2) whether or not individualized Head-Related Impulse Response filters are used; (3) the number of sound-track channels: mono, stereo, and 5.2 surround; and (4) whether or not reverberation is used. Experiments are repeated a number of times with listeners requested to make judgement comparisons regarding: externalization, quality of the frontal image, timbre, and preference. Open headphones (AKG 1000) are used so that listeners can compare the various binaural spatial-audio rendering conditions with standard non-binaural headphone presentation and also loudspeaker presentation. The results indicate the impact of varying degreesof realism on various aspects of binaural spatial-audio music perception.
INCE/J Vibration Measurement Manual for Buildings—Part 1: A commentary on the manual for vibration measurement
Authors: Yokoshima Shigenori
Published: November 2016

Vibration Regulation Law in Japan has regulated vertical ground vibration caused by road traffic, operation of a factory machine, and construction work since 1976. However, inhabitants perceive vibrations not on the ground but in buildings which are residential spaces. For the purpose of assessing building vibrations, technical committee on Environmental Vibration Evaluation in the Institute of Noise Control Engineering (INCE/J) organized Vibration Manual for Buildings. The manual is desired to provide technical materials contributing to effective measures for the vibrations to be solved. To achieve the aim, the manual concerns the method of measurement of the following vibration characteristics: propagation of ground vibrations, transmission of house vibrations, and vibration exposures to inhabitants according to vibration sources. In addition, the accumulation of detailed measurement data contributing to the revision of vibration index in the future is an important issue. Specifically, items of the manual are the following: scope, measurement (measurement unit, instrument, location direction, time zone, and notices) and calculation of measurements. For example, measurement unit is based on one-third octave band analysis. The vibration shall be measured at the location in building where the inhabitants perceive highest magnitude of the vibration.
INCE/J Vibration Measurement Manual for Buildings—Part 3: Measurement example of building vibrations
Authors: Hirao Yoshihiro
Published: November 2016

The environmental impact on humans in buildings is caused by ground-borne vibration from rail transit systems, road traffic, construction sites, and industrial plants. To estimate the effect of vibration on humans, it is necessary to measure the tri-axial vibrations in the vertical and horizontal directions in buildings specified in ISO 2631-2:2003 or “Vibration Measurement Manual for Buildings” publicized by the Technical Subcommittees on Environmental Vibration Evaluation of The Institute of Noise Control Engineering of Japan. In this measurement example of building vibrations, vibration measurement was carried out for eight hours in a three-story, wooden detached house adjacent to a construction site. The residents perceived discomfort or annoyance from the vibration caused by the demolition work at the construction site. Five vibration measurement devices recorded simultaneously the vibration accelerations on the floor of each story, the concrete substructure and the asphalt pavement surface near the substructure. The 1/3 octave band vibration accelerations of each floor were estimated by the vibration perception threshold range of the vibration measurement manual. The vibration amplifications caused by building structural resonance was evaluated as ratios and level differences in the vibration accelerations measured at the ground near the substructure and floors in the houses.
Vertical sensory evaluation on residential floor by traffic vibration
Authors: Matsuda Toru , Inoue Katsuo , Tomita Ryuta
Published: November 2016

If vibration failures have occurred in building caused by traffic, in Japan, it is often evaluated by “Guidelines for the evaluation of habitability to building vibration.” This evaluation method has to be collated acceleration maximum value of 1/3 octave band analysis on the evaluation curve, to evaluate the response acceleration of adjacent frequency bands to reference curve. This performance evaluation curves are presented from experimental results based on sine vibration, under real environment, random vibration containing multiple frequency components. Therefore, it is necessary to consider the influence of the frequency components other than determination frequency, because it is considered to affect the vibration sense. Therefore, in this paper, as a basic study, we examined the good evaluation physical quantity of corresponding to vibration sense from relationship of the vibration sense and vibration response physical quantity for traffic vibration of railway and road. As a result, in the range of more than feeling the vibration, in the case of the narrowband vibration response, which is equal to broadband vibration response, the broadband vibration response has been suggested the increase in perception and discomfort. That is, the frequency characteristics other than the determination frequency have been suggested as one of the factors affecting vibration sense.
Measurements of a wave barrier trench for isolation of rail vibration
Authors: Dong David W. , LoVerde John
Published: November 2016

Where buildings are adjacent to railroad tracks, one option for reducing levels of ground vibration is to dig a trench between the tracks and the project to act as a wave barrier. The application of this method has been rare within the United States, and consequently, practical experience is very limited. On a recent project of the authors, a wave barrier trench was constructed [Dong and LoVerde, JASA 139, 2159 (2016)]. Measurements have been performed is various conditions both before and after construction of the trench. The vibration insertion loss was measured and compared to theory, and recommendations based on the experience are provided. This paper extends the analysis with additional information and data.
Vibration isolation of large fan array air handling units in healthcare
Authors: Logsdon Edward
Published: November 2016

A new hospital facility constructed in Denver, CO, has all the mechanical equipment that is typically on the roof of the building located directly over all the Operating Rooms (ORs). Many of the ORs are used for procedures involving equipment found in new facilities like high powered microscopes for laser eye surgery or neurosurgery, ceiling mounted high-definition video displays and robotic surgical systems using high resolution cameras. All of which are vibration sensitive. Also, in the future the client wanted flexibility in how the operating rooms are used as the equipment and procedures will change. Because “fan array” mechanical units, produce less vibration than traditional air handling units, they were selected by the design team. The air handling units varied in size from medium with six supply and six return fans to very large with 22 supply and 16 return fans. Because of their size and location in the building, the units were loaded into the facility in multiple modular sections that were then bolted together. This required the development of a vibration isolation solution that allowed for the easy assembly of the mechanical units on site. The rational for the location of the mechanical rooms above the operating rooms will be discussed along with the vibration criteria, analysis, and details of the isolation system. This includes vibration measurements of the final results.
Asymmetrical interpretation of English liquid consonants by Japanese speakers
Authors: Kondo Mariko
Published: November 2016

Japanese speakers have difficulty in differentiating English /l/ and /r/ because they are not contrastive. Actually, variations of both /l/ and /r/ occur in Japanese speech. The most common realization of Japanese /r/ is alveolar tap [ɾ] and all variants of both /l/ and /r/ are considered as allophones of /r/. Previously, it was found that Japanese speakers have more problems with /l/ than with /r/ in their English production. So, this study investigates why these differences occur. Analysis of Japanese speakers’ mimicry speech of (a) American English and (b) English accented Japanese suggested that Japanese speakers are aware of acoustic and articulatory features of English approximant [ɹ]. Japanese speakers overused approximant [ɹ] and r-colored vowels in their mimicries of both (a) and (b). Further articulatory analysis of Japanese and English consonants showed that the English approximant [ɹ] is quite distinct from Japanese consonants, all of which lack lip rounding. The results of these studies suggest that Japanese speakers may not be able to recognize English /l/ and /r/ as separate phonemes, but that they can hear the approximant [ɹ] as it forms a new sound category, whereas they interpret /l/ as /r/.
Individual-based accent clustering of World Englishes using the Speech Accent Archive
Authors: Minematsu Nobuaki
Published: November 2016

In a language class of English, one specific type of pronunciation is often adopted as model pronunciation and learners try to imitate that pronunciation. Even though they acquire native-like pronunciation successfully, once they go out to the real world of spoken English, they surely encounter the pronunciation diversity of English and feel the necessity to survive it. As is well-known, English pronunciation is altered variously depending on the language background of speakers, called accents. This talk describes a technical attempt of automatic and individual-based clustering of these accents using the Speech Accent Archive. This technique may be used to realize a really individual-based map of World Englishes, which can be used to introduce learners to the real state of English. For clustering, the accent gap has to be quantitatively estimated between any two speakers of the archive, where non-linguistic factors such as age and gender have to be adequately cancelled in estimation. Pronunciation structure analysis is used for cancellation and experiments show that the estimated gaps have a better correlation to IPA-based manually defined gaps than phoneme-based gaps have to the IPA-based gaps.