bluuebunny/crossref_metadata_2025 huggingface dataset:
Acoustic field measurements and bottlenose dolphin hearing thresholds using single-frequency and frequency-modulated tones
Authors: Finneran James J. , Schlundt Carolyn E.
Published: October 2013

Studies of underwater hearing are often hampered by the behavior of sound waves in small experimental tanks. At lower frequencies, tank dimensions are often not sufficient for free-field conditions, resulting in large spatial variations of sound pressure. These effects may be mitigated somewhat by increasing the frequency bandwidth of the sound stimulus, so effects of multipath interference average out over many frequencies. In this study, acoustic fields and bottlenose dolphin (Tursiops truncatus) hearing thresholds were compared for pure-tone and frequency-modulated stimuli. Experiments were conducted in a vinyl-walled, seawater-filled pool approximately 4×5×1.5 m. Sound stimuli consisted of 500-ms tones at 13 carrier frequencies between 1 and 100 kHz. Frequency-modulated stimuli featured both linear and sinusoidal modulating waveforms with 5%, 10%, and 20% bandwidths. Acoustic fields were measured (without the dolphin present) at three depths over a 60×65-cm grid with a 5-cm spacing. Hearing thresholds were measured using a behavioral response paradigm and up/down staircase technique. Frequency-modulated stimuli with a 10% bandwidth resulted in significant improvements to the sound field without substantially affecting the dolphins hearing thresholds. [Work supported by ONR.]
Auditory brainstem response recovery rates during double-pulse presentation in the false killer whale (Pseudorca crassidens): A mechanism of automatic gain control?
Authors: Nachtigall Paul E. , Supin Alexander Ya. , Breese Marlee
Published: October 2013

The outgoing echolocation pulse and the return echo response can be approximately examined in the auditory system of an echolocating animal by presenting two pulses and determining the forward-masking effect of the first pulse on the response to the second pulse using auditory-evoked potential procedures. False killer whale, Pseudorca crassidens, auditory brainstem responses (ABR) were recorded using a double-click stimulation paradigm specifically measuring the recovery of the second (test) response (to the second click) as a function of the length of the interclick interval (ICI) following various levels of the first (conditioning) click. At all click intensities, the slopes of the recovery functions were almost constant: 0.60.8 V per ICI decade. Therefore, even when the conditioning-to-click level ratio was kept constant, the duration of recovery was intensity dependent: the higher intensity the longer the recovery. The conditioning-to-test-click level ratio strongly influenced the recovery time: the higher the ratio, the longer the recovery. This dependence was nearly linear, using a logarithmic ICI scale with a rate of 2530 dB per ICI decade. These data were used for modeling the interaction between the emitted click and the echo in the auditory system during echolocation.
Estimates of bio-sonar characteristics of a free-ranging Ganges river dolphin
Authors: Ura Tamaki , Sugimatsu Harumi , Inoue Tomoki , Bahl Rajendar , Kojima Junichi , Akamatsu Tomonari , Behera Sandeep , Pattnaik Ajit , Kahn Muntaz , Kar Sudhakar , Sekhar Kar Chandra , Fukuchi Tetsuo , Takashi Hideyuki , Swain Debabrata
Published: October 2013

This paper reports the first known studies of the bio-sonar characteristics of an isolated free-ranging Ganges river dolphin, Platanista gangetica. The animal preferred to roam in a deeper tract of the otherwise shallow river. The click sounds of the dolphin were recorded over a period of 2 days on a 3.2-meter-long high-frequency hydrophone array composed of three hydrophones forming an equispaced linear array and another two hydrophones in conjunction with the central hydrophone forming an SSBL triangular array in a plane perpendicular to the array axis. The array was deployed both in horizontal and vertical configurations. The array structure provided 3-D measurements of the source location through measurement of the interelement time delay. Bio-sonar characteristics such as click duration, bandwidth, and interclick intervals in click trains have been reported. Measurements of dolphin track and the relative click levels on the array hydrophones have been used to obtain a preliminary characterization of the animal’s beam pattern.
Discriminating between the clicks produced by a bottlenose dolphin when searching for and identifying an object during a search task
Authors: Bohn Sandra , Kuczaj Stan , Houser Dorian
Published: October 2013

Clicks collected from an echolocating bottlenose dolphin completing a search task were compared in order to determine if the clicks produced when the dolphin was acquiring the target differed from the clicks produced when the dolphin was searching for the target. The clicks produced by a free-swimming dolphin completing the search task were recorded using a biosonar measurement tool (BMT), an instrumentation package carried by the dolphin that collected both the outgoing clicks and the returning echoes. A discriminant function analysis classified the clicks as search or acquisition using the variables of peak-to-peak amplitude, duration, peak frequency, center frequency, and bandwidth. The acquisition clicks were classified more accurately than the search clicks. Acquisition clicks and search clicks were significantly different across all five of the variables. These results suggest that the clicks produced by bottlenose dolphins acquiring a target are different than those produced by dolphins searching for a target.
Echo highlight amplitude and temporal difference resolutions of an echolocating Tursiops truncatus
Authors: Muller Mark W. , Au Whitlow W. L. , Nachtigall Paul E. , Breese Marlee , Allen III John S.
Published: October 2013

A dolphin’s ability to discriminate targets may greatly depend on the relative amplitudes and the time separations of echo highlights within the received signal. Previous experiments with dolphins have varied the physical parameters of targets, but did not fully investigate how changes in these parameters corresponded with the composition of the scattered acoustic waveforms and the dolphin’s subsequent response. A novel experiment utilizes a phantom echo system to test a dolphin’s detection response of relative amplitude differences of secondary echo highlights and the time separation differences of all the echo highlights both within and outside the animal’s integration window. By electronically manipulating these echoes, the underlying acoustic classification cues can be more efficiently investigated. In the first study, the animal successfully discriminated between a standard echo signal and one with the middle highlight amplitude at −7 dB. When the middle highlight amplitude was raised to −6 dB, the animal’s discrimination performance radically dropped to 65%. This study suggests the animal may not be as sensitive to the secondary echo highlights as previously proposed. The experiments were repeated for the trailing highlight amplitude and the time separations between the primary and middle highlights and the middle and trailing highlights.
Quantitative imaging of tumor blood flow with contrast ultrasound
Authors: Burns Peter N. , Karshafian Raffi , Hudson John
Published: October 2013

The point at which a solid cancer develops its own blood supply marks the onset of malignant progression. This process, known as angiogenesis, makes oxygen and nutrients available for growth and provides a path for metastatic spread. Angiogenesis is not only of interest as a diagnostic hallmark of malignancy, but also as a target for new therapeutic strategies. Assessing antiangiogenic therapies noninvasively poses problems—flow velocities (<1 mm/s) and vessel diameters (<50 μm) are below resolutions of direct imaging. Vessels are disorganized without the tree-like structure of normal vasculature. We have investigated the potential role of microbubble disruption-replenishment flow measurement in monitoring antivascular treatment of an animal tumor. The currently used monexponential model incorrectly considers the vasculature a perfect mixing chamber. Simple fractal models of the circulation provide a distribution of vessel diameters which, combined with the geometry of the disruption and detection beams, produce better models of replenishment following acoustic bubble disruption. These not only measure flow, but also predicts differences between organized and disorganized circulations, even with equal flow and vascular volume. If detectable, such differences might be used to characterize vascular organization below the resolution limit of an ultrasound image.
Ultrasonic spore lysis and the release of intracellular content in a microfluidic channel
Authors: Marina Oana C. , Ward Michael D. , Dunbar John M. , Kaduchak Gregory
Published: October 2013

Ultrasonic lysis of suspended spores in a microfluidic channel is a promising alternative to conventional spore disruption techniques that include bead beating as the spore lysis gold standard. Our overall research goal is to obtain an automated detection system with complete sample preparation and lysis steps in a microfluidic channel. Previously, much work in this area has focused on organism viability rather than the release of intracellular material. Our research focuses on quantifying the amount of intracellular content (e.g., DNA, proteins, etc.) that is released by acoustic lysis for detection by the sensor. Elucidating the efficacy of acoustics on the release of intracellular material requires reliable methods to quantify the released intracellular content (nucleic acids and proteins). The device used for lysing spores consists of a microfluidic chamber with one acoustically active wall. The chamber depths are in the range of 100–200 m. Channels tested in the 70-kHz to 1-MHz frequency range show that the efficiency of intracellular release depends on the operating frequency of the device and the properties (concentration, composition) of the spore suspensions. Experimental results on viability and released intracellular content are discussed. [Work supported by LANL LDRD.]
Antitumor effectiveness of cisplatin with ultrasound and nanobubbles
Authors: Kodama Tetsuya , Watanabe Yukiko , Konno Kiyoe , Horie Sachiko , Aoi Atsuko , Vassaux Geroges , Mori Shiro
Published: October 2013

The potentiation of antitumor effect of cis-diamminedichloroplatinum (II), cisplatin, with ultrasound (1 MHz, 0.6 MPa) and lipid-shelled nanobubbles in vitro (EMT6, C26, MCF7, A549) and in vivo on s.c. tumor in mice (HT29-expressing luciferase) were evaluated. In vitro and in vivo antitumor effects were measured by an MTT assay and a real-time in vivo imaging, respectively. The effective antitumor effect was seen both in vitro and in vivo when ultrasound and nanobubbles were used, while other treatment groups with cisplatin with ultrasound did not show the effectiveness. The antitumor effect was not attributed to necrosis but apoptosis, which was confirmed by increase in the activity of the pro-apoptosis signal caspase-3 and Bax. In conclusion, the combination of ultrasound and nanobubbles with cisplatin is an effective chemotherapy of solid tumors and may prove useful in clinical application.
Sonoporation by single-shot pulsed ultrasound with microbubbles—Little effect of sonochemical reaction of inertial cavitation
Authors: Okada Kengo , Kudo Nobuki , Yamamoto Katsuyuki
Published: October 2013

Sonoporation is a technique for introducing large molecules into a cell by exposure to ultrasound, and it has a potential application for gene transfection. Although continuous-wave ultrasound is generally used for this technique, we have been using single-shot pulsed ultrasound with microbubbles. To determine the contribution of the sonochemical effect of inertial cavitation under the condition of single-shot exposure, we compared rates of cell membrane damage in the presence and absence of a free radical scavenger (cysteamine, 5 mM). Cells with microbubbles in their vicinity were exposed to pulsed ultrasound of 1.1 MPa in negative peak pressure under microscopic observation, and the numbers of total and damaged cells in the view field were counted. The damage rates were 8.1±4.0% and 10.3±6.3% in the presence (n=17) and absence (n=25) of the scavenger, respectively, and the average number of total cells was 772±285. Since there was no significant difference, we concluded that the cell membrane damage observed in our exposure condition was not caused by the sonochemical effect but by the mechanical effect of inertial cavitation. [Research was supported by a grant-in-aid for scientific research from the Ministry of Education, Science, Sports and Culture, Japan.]
Introduction of the Real World Computing music database
Authors: Goto Masataka
Published: October 2013

This paper introduces the RWC (Real World Computing) Music Database, a copyright-cleared music database that is available to researchers as a common foundation for research. Shared databases are common in other research fields and have contributed importantly to progress in those fields. The field of music information processing, however, has lacked a common database of musical pieces and a large-scale database of musical instrument sounds. The RWC Music Database was therefore built in fiscal 2000 and 2001 as the world’s first large-scale music database compiled specifically for research purposes. It contains six original collections: the Popular Music Database (100 pieces), Royalty-Free Music Database (15 pieces), Classical Music Database (50 pieces), Jazz Music Database (50 pieces), Music Genre Database (100 pieces), and Musical Instrument Sound Database (50 instruments). To address copyright issues, all 315 musical pieces were originally composed, arranged, or performed, and all instrumental sounds were originally recorded. The database has already been distributed to more than 200 research groups and is widely used. In addition, a continuous effort has been undertaken to manually annotate a set of music-scene descriptions for the musical pieces, called AIST Annotation, which consists of the beat structure, melody line, and chorus sections.
Japanese traditional singing on the same lyrics
Authors: Nakayama Ichiro , Yanagida Masuzo
Published: October 2013

Described is a database of Japanese traditional singing together with supplementary recording of Bel Canto for comparative studies. Singing sounds and spoken speech by the same singers are recorded in pair to form the body of the database. This database covers most of genres of Japanese traditional singing, such as Shinto prayers, Buddist prayers, Nor, Kyogen, Heikyoku, Sokyoku, Gidayu-bushi, Kabuki, Nagauta, Tokiwazu, Kiyomoto, Itchu-bushi, Shinnai, Kouta, Zokkyoku, Rokyoku, Shigin, Ryukyu-clasico, Goze-uta, etc. All the sounds were recorded in anechoic chambers belonging to local institutions, mainly in Osaka and Tokyo, asking 78 professional singers including 18 ‘‘Living National Treasures’’ to sing as informants. The most important point of this database is that an original lyric especially prepared for this recording is commonly used to make comparative studies easy. All the subjects are asked to sing the common lyrics in their own singing styles. Shown here are comparisons of formant shifts in vowels from ordinary speaking to singing for some singers, and comparison of temporal features of fundamental frequency between Japanese traditional singing and Western Bel Canto. [Work supported by the Academic Frontier Project, Doshisha University.]
Accompaniment included song waveform retrieval based on framewise phoneme recognition
Authors: Yaguchi Yuichi , Oka Ryuichi
Published: October 2013

A novel approach is presented for a retrieval method that is useful for waveforms of songs with accompaniment. Audio signals of songs have some different acoustical characteristics from speech signals. Furthermore, the length per mora of signals is longer than that of speech. Therefore, the authors suggest a sound retrieval system for application to musical compositions, including songs, that extracts framewise acoustical characteristics and uses a retrieval method for absorbing phoneme length. First, the system prepares two sets of phoneme identification functions that have corresponding order, but for which phoneme sets belong to different environments of accompaniment-included or accompaniment-reduced. Next, musical compositions are put into database and the query song wave converts a waveform to a label sequence using framewise phoneme recognition derived by Bayesian estimation that applies each phoneme identification function according to whether it is accompaniment-included or not. Finally, the system extracts an interval area, such as query data, from a database using spotting recognition that is derived using continuous dynamic programming (CDP). Retrieval method results agree well with earlier results [Y. Yaguchi and R. Oka, AIRS2005, LNCS3689, 503–509 (2005)] that applied the same musical composition set without accompaniment.
Musical scales, signals, quantum mechanics
Authors: Sevgen Alpar
Published: October 2013

Scales, being finite length signals, allow themselves to be treated algebraically: key signatures are related to the ‘‘ring’’ property of the scale labels; cyclically permuted scales and their mirror images have the same number of sharps and flats; and complementary scales (like major and pentatonic) have their sharp and flat numbers exchanged. A search for minimum principles to select among all possible scales those employed in music yields two possibilities: (a) minimize total number of accidentals and (b) minimize frequency fluctuations in a scale. Either of these minimum principles helps filter those scales employed in music from the universe of all scales, setting up very different criteria than the harmonic ratios used by musicians. The notes of the scales employed in music seem to prefer to stay as far apart from each other as possible. Operators that step through the multiplet members of scales with N semitones form a complete set of operators together with those that step through their eigenvectors. The mathematics reveals the discrete Fourier transformations (DFT) and is identical to finite state quantum mechanics of N-level Stern-Gerlach filters worked out by J. Schwinger.
The daily rhythm of soundscape
Authors: Schulte-Fortkamp Brigitte , Fiebig Andr
Published: October 2013

With respect to people’s minds, soundscapes can be considered as dynamic systems characterized by the time-dependent occurrence of particular sound events embedded in specific environments. Therefore, an adequate evaluation of environmental noise will reflect the continually varying acoustical scenery and its specific perception. An acoustical diary shall provide information about the daily routine and subjectively perceived sound exposure of residents. It relies on cognitive and emotional aspects of perceiving and evaluating sounds. It gives insight into evaluating processes and their contextual parameters because of its spontaneous character. It includes and refers to long-term acoustic measurements. Simultaneous measurements for elaborate acoustical analyses will be taken outside the homes regarding the moments of essential sound events. The aim is to collect information about the daily rhythm regarding acoustic events, whereby the focus also should be placed on sound events that are well accepted to deepen the explication of data with respect to the analysis. Procedure and results will be discussed.
Acoustic environmental problems at temporary shelters for victims of the Mid-Niigata Earthquake
Authors: Nagahata Koji , Suzuki Norio , Sakamoto Megumi , Tanba Fuminori , Kaneko Shin-ya , Fukushima Tetsuhito
Published: October 2013

An earthquake on 23 October 2004 inflicted heavy damage on the Mid-Niigata district. The earthquake isolated Yamakoshi village; consequently, all the village residents were forced to evacuate to temporary shelters in neighboring Nagaoka city for 2 months. Two types of temporary shelters were used: gymnasiums, and buildings with large separated rooms similar to community centers. A questionnaire survey and interviews (N=95) were conducted to elucidate problems of the living environment at the temporary shelters. This study analyzed acoustic environmental problems there. Noise-related problems were noted by 40 respondents (46.5%): they were the fifth most frequently cited environmental problems. Several serious complaints, e.g., general annoyance at the shelters and footsteps of refugees at night, were only indicated by respondents who had evacuated to the gymnasiums. However, some problems, e.g., the clamor of children, including crying babies and voices of other refugees, were indicated by respondents irrespective of the type of the shelters to which they had been evacuated. Therefore, buildings like community centers were more desirable for temporary shelters, at least from the perspective of noise problems.
The complexity of environmental sound as a function of seasonal variation
Authors: Shibayama Hideo
Published: October 2013

Residential land is performed for a surrounding area of a suburban local city. As a result of urbanization, an area of rich natural environments became narrow. For the animals and plants for whom a river and a forest are necessary, it becomes difficult to live. Environmental sound produced by the tiny insects in this area is changing from year to year. Catching the conditions for the developmental observations and environmental preservation in natural environments, we continue to measure the environmental sound as the time-series data. We estimate the complexity for these waveforms of the measured environmental sound in the season when insects chirp and do not chirp. For estimation of the complexity, we evaluate by the fractal dimension of the environmental sound. Environmental sound in early autumn is mainly generated by insects in the grass and on the trees. And, the fractal dimension for the sound waveforms of chirping of insects is up to 1.8.
In vivo measurement of mass density and elasticity of cancellous bone using acoustic parameters for fast and slow waves
Authors: Otani Takahiko
Published: October 2013

Cancellous bone (spongy bone) is comprised of a porous network of numerous trabecular elements with soft tissue in the pore space. The effect of decreasing bone density, namely a symptom of osteoporosis, is greater for cancellous bone than for dense cortical bone (compact bone). Two longitudinal waves, the fast and slow waves, are clearly observed in cancellous bone, which correspond to ‘‘waves of the first and second kinds’’ as predicted by Biot’s theory. According to experimental and theoretical studies, the propagation speed of the fast wave increases with bone density and that of the slow wave is almost constant. Experimental results show that the fast wave amplitude increases proportionally and the slow wave amplitude decreases inversely with bone density. However, the attenuation constant of the fast wave is almost independent of bone density and the attenuation constant of the slow wave increases with bone density. The in vivo ultrasonic wave propagation path is composed of soft tissue, cortical bone, and cancellous bone and is modeled to specify the causality between ultrasonic wave parameters and bone mass density of cancellous bone. Then, mass density and elasticity are quantitatively formulated and estimated.
Ultrasonic characteristics of in vitro human cancellous bone
Authors: Mano Isao , Yamamoto Tadahito , Hagino Hiroshi , Teshima Ryota , Tsujimoto Toshiyuki , Otani Takahiko
Published: October 2013

Cancellous bone is comprised of a connected network of trabeculae and is considered as an inhomogeneous and anisotropic acoustic medium. The fast and slow longitudinal waves are clearly observed when the ultrasonic wave propagates parallel to the direction of the trabeculae. The propagation speed of the fast wave increases with bone density and that of the slow wave is almost constant. The fast wave amplitude increases proportionally and the slow wave amplitude decreases inversely with bone density. Human in vitro femoral head was sectioned to 10-mm-thick slices perpendicularly to the femoral cervical axis. These cancellous bone samples were subjected to the ultrasonic measurement system LD-100 using a narrow focused beam. The propagation speed and the amplitude of the transmitted wave both for the fast and slow waves were measured at 1-mm intervals. The local bone density corresponding to the measured points was obtained using a microfocus x-ray CT system. Experimental results show that the propagation speeds and amplitudes for the fast and slow waves are characterized not only by the local bone density, but also by the local trabecular structure.
The effect of hydroxyapatite crystallite orientation on ultrasonic velocity in bovine cortical bone
Authors: Yamato Yu , Yamazaki Kaoru , Nagano Akira , Mizukawa Hirofumi , Yanagitani Takahiko , Matsukawa Mami
Published: October 2013

Cortical bone is recognized as a composite material of diverse elastic anisotropy, composed of hydroxyapatite (HAp) crystallite and type 1 collagen fiber. The aim of this study is to investigate the effects of HAp orientation on elastic anisotropy in bovine cortical bone. Eighty cubic samples were made from the cortical bone of two left bovine femurs. Longitudinal wave velocity in orthogonal three axes was measured using a conventional pulse echo system. For evaluating the orientation of HAp crystallite, x-ray diffraction profiles were obtained from three surfaces of each cubic sample. The preference of crystallites showed strong dependence on the direction of surface. The C-axis of crystallites was clearly preferred to the bone axial direction. The velocity in the axial direction was significantly correlated with the amounts of HAp crystallites aligning to the axial axis. The HAp orientation and velocity varied according to the microstructures of the samples. The samples with Haversian structure showed larger preference of crystallites than plexiform samples in the axial direction. These results show clear effects of crystallites orientation on velocity.
3-D numerical simulations of wave propagation in trabecular bone predicts existence of the Biot fast compressional wave
Authors: Haiat Guillaume , Padilla Frederic , Laugier Pascal
Published: October 2013

Trabecular bone is a poroelastic medium in which the propagation of two longitudinal waves (fast and slow) has been observed. The 3-D finite-difference time-domain simulations neglecting absorption coupled to 3-D microstructural models of 34 trabecular bone reconstructed from synchrotron radiation microtomography are shown to be suitable to predict both types of compressional wave in the three orthogonal directions. The influence of bone volume fraction (BV/TV) on the existence of the fast and slow waves was studied using a dedicated iterative image processing algorithm (dilation, erosion) in order to modify all 34 initial 3-D microstructures. An automatic criteria aiming at determining the existence of both wave modes was developed from the analysis of the transmitted signals in the frequency domain. For all samples, the fast wave disappears when bone volume fraction decreases. Both propagation modes were observed for BV/TV superior to a critical value for 2, 13, and 17 samples according to the direction of propagation. Above this critical value, the velocity of the fast (slow) wave increases (decreases) with BV/TV, consistent with Biot’s theoretical predictions. This critical value decreases when the degree of anisotropy increases, showing coupling between structural anisotropy and the existence of the fast wave.
Assessment of bone health by analyzing propagation parameters of various modes of acoustic waves
Authors: Sarvazyan Armen , Egorov Vladimir , Tatarinov Alexey
Published: October 2013

A method for assessment of bone based on comprehensive analysis of waveforms of ultrasound signals propagating in the bone is presented. A set of ultrasound propagation parameters, which are differentially sensitive to bone material properties, structure, and cortical thickness, are evaluated. The parameters include various features of different modes of acoustics waves, such as bulk, surface, and guided ultrasonic waves in a wide range of carrier frequencies. Data processing algorithms were developed for obtaining axial profiles of waveform parameters. Such profiles are capable of revealing axial heterogeneity of long bones and spatially nonuniform pathological processes, such as osteoporosis. The examination procedure may include either one long bone in the skeleton, like the tibia, radius of the forearm, etc., or several bones in sequence to provide a more comprehensive assessment of the skeletal system. Specifically, for tibia assessment, a multi-parametric linear classifier based on a DEXA evaluation of skeleton conditions has been developed. Preliminary results of the pilot clinical studies involving 149 patients have demonstrated early stages of osteoporosis detection sensitivity of 80% and specificity of 67% based on DEXA data as the gold standard. [Work was supported by NIH and NASA grants.]
Toward bone quality assessment: Interference of fast and slow wave modes with positive dispersion can account for the apparent negative dispersion
Authors: Miller James G. , Marutyan Karen , Holland Mark R.
Published: October 2013

The goal of this work was to show that apparently negative dispersion in bone can arise from interference between fast wave and slow wave longitudinal modes, each of positive dispersion. Simulations were carried out using two approaches, one based on the Biot-Johnson model and the second independent of that model. The resulting propagating fast wave and slow wave modes accumulated phase and suffered loss with distance traveled. Results of both types of simulation served as the input into a phase and magnitude spectroscopy algorithm (previously validated with experimental data) in order to determine the phase velocity as a function of frequency. Results based on both methods of simulation were mutually consistent. Depending upon the relative magnitudes and time relationships between the fast and slow wave modes, the apparent phase velocities as functions of frequency demonstrated either negative or positive dispersions. These results appear to account for measurements from many laboratories that report that the phase velocity of ultrasonic waves propagating in cancellous bone decreases with increasing frequency (negative dispersion) in about 90% of specimens but increases with frequency in about 10%. [Work supported in part by Grant NIH R37HL40302.]
Threshold of hearing for pure tones between 16 and 30 kHz
Authors: Ashihara Kaoru
Published: October 2013

Hearing thresholds for pure tones were obtained at 2-kHz intervals between 16 and 30 kHz in an anechoic chamber. Measured 50 cm from the sound source, the maximum presentation sound pressure level ranged from 105 to 112 dB depending on the frequency. To prevent the listener from detecting the quantization noise or subharmonic distortions at low frequencies, a pink noise was added as a masker. Using a 3-down 1-up transformed up-down method, thresholds were obtained at 26 kHz for 10 out of 32 ears. Even at 28 kHz threshold values were obtained for 3 ears, but none were observed for a tone at 30 kHz. Above 24 kHz, the thresholds always exceeded 90 dB SPL. Between 16 and 20 kHz thresholds increased abruptly, whereas above 20 kHz the threshold increase was more gradual.
Loudness growth in individual listeners with hearing loss
Authors: Marozeau Jeremy , Florentine Mary
Published: October 2013

Recent research indicates that there are large individual differences in how loudness grows with level for listeners with sensorineural hearing losses of primarily cochlear origin. Studies of loudness discomfort level suggest that loudness for most of these impaired listeners approaches the loudness experienced by the normal listeners at high levels. Loudness growth at low levels is still controversial. Although it is now well established that loudness at threshold is greater than zero, its exact value is unknown. If this value is the same for normal and impaired listeners, then the loudness growth for the impaired listeners must be steeper in order to catch up to normal at high levels. This phenomenon is called recruitment. If the loudness at threshold for impaired listeners is higher than that for normal listeners, then the impaired listeners will no longer be able to perceive sounds as soft. This phenomenon is called softness imperception. Results from two experiments suggest that: (1) individual differences are more important for impaired listeners than for normal listeners; (2) some impaired listeners seem to show recruitment, others softness imperception; and (3) averaging the results across the impaired listeners will mask these differences. [Work supported by NIH/NIDCD grant R01DC02241.]
Growth of loudness in cochlear implant listening
Authors: Smith Robert L. , Sanpetrino Nicole
Published: October 2013

Cochlear implants (CIs) roughly mimic the transformation from sound frequency to cochlear place that occurs in acoustic hearing. However, CIs are relatively less capable of creating the intensive transformations that normal peripheral auditory processing provides. This is partly because CIs have small operating ranges on the order of 10:1 in electric current, compared to the 1000000:1 operating range for sound-pressure level (SPL) in acoustic hearing. Furthermore, loudness in acoustic hearing grows as a compressive power function of SPL. In contrast, loudness reportedly grows as a more expansive function of current for CI users, i.e., a power law with a large exponent or an exponential function. Our results, obtained using the minimally biased method of magnitude balance without an arbitrary standard, reveal a previously unreported range of shapes of CI loudness functions, going from linear to power laws with exponents of 5 or more. The shapes seem related in part to the etiology of deafness preceding cochlear implantation, although the shapes can vary with stimulating conditions within a subject. Furthermore, differential sensitivity to changes in current appears to be related to the shape of the corresponding loudness function. Implications for sound processing in electric and acoustic hearing will be discussed.
Cortical representation of processing Japanese phonemic and phonetic contrasts
Authors: Funatsu Seiya , Imaizumi Satoshi , Hashizume Akira , Kurisu Kaoru
Published: October 2013

This study investigated how Japanese speakers process phonemic and phonetic contrasts using voiced and devoiced vowel /u/ and /÷u/. During six oddball experiments, brain responses were measured using magnetoencephalography. Under the phonemic condition, a frequent stimulus /ch÷ita/ was contrasted with a deviant /ts÷uta/, and a frequent /ts÷uta/ with a deviant /ch÷ita/. Under the phonetic condition, a frequent /ts÷uta/ was contrasted with a deviant /tsuta/, and a frequent /tsuta/ with a deviant /ts÷uta/. Under the segment condition, vowel segments, /÷u/ and /u/, extracted from spoken words, were contrasted. The subjects were 13 native Japanese speakers. The equivalent current dipole moment (ECDM) was estimated from the mismatch field. Under the phonetic condition, the ECDM elicited by the voiced deviant was significantly larger than that elicited by the devoiced deviant in both hemispheres (p<0.01), while there were no significant deviant-related differences in ECDM under the phonemic condition in both hemispheres. Under the segment condition, the ECDM elicited by the voiced deviant and devoiced deviant did not differ significantly in either hemispheres. These results suggested that the ECDM asymmetries between the voiced and the devoiced deviant observed under the phonetic condition did not originate from the acoustical difference itself, but from the phonetic environment.
Acoustic cues for distinguishing consonant sequences in Russian
Authors: Davidson Lisa , Roon Kevin
Published: October 2013

In Russian, the same consonant sequences are permitted in various environments. Consequently, the presence of a word boundary or reduced vowel can be phonologically contrastive (e.g. [z■d■vatj] ‘‘to assign,’’ [zd■vatj] ‘‘to turn in’’), and both learners and experienced listeners likely rely on fine acoustic cues to discriminate the phonotactic structures they hear. In this study, the acoustic characteristics of consonant sequences are examined to establish which cues may distinguish (a) word-initial clusters (C1C2); (b) consonant-schwa-consonant sequences (C1VC2); and (c) sequences divided by a word boundary (C1♯C2). For all three sequence types, native Russian speakers produced phrases containing three categories of target sequences: stop+consonant, fricative+consonant, and nasal+consonant. Results show no significant differences in C1 burst duration for initial stops, though a longer interconsonantal duration is a reliable cue to schwa presence in C1VC2. C2 is significantly longer in C♯C than in other sequences. For clusters, when C1 is a stop, there are no significant differences in duration with other sequence types, but other C1’s are significantly shorter. This suggests that articulatory overlap, which may lead to C1 shortening for fricative or nasal-initial clusters, is reduced in stop-initial clusters to ensure that the stop is released and recoverable. [Research supported by NSF.]
Lipread me now, hear me better later: Crossmodal transfer of talker familiarity effects
Authors: Sanchez Kauyumari , Rosenblum Lawrence D. , Miller Rachel M.
Published: October 2013

There is evidence that for both auditory and visual speech perception (lipreading) familiarity with a talker facilitates speech recognition [Nygaard et al., Psychol. Sci. 5, 42 (1994); Yakel et al., Percept. Psychophys. 62, 1405 (2000)]. Explanations of these effects have concentrated on the retention of talker information specific to each of these modalities. It could be, however, that some amodal, talker-specific articulatory style information is retained to facilitate speech perception in both modalities. If this is true, then experience with a talker in one modality should facilitate perception of speech from that talker in the other modality. To test this prediction, subjects were given one hour of experience lipreading from a talker and were then asked to recover speech-in-noise from either this same talker or from a different talker. Results revealed that subjects who lipread and heard speech from the same talker performed better on the speech-in-noise task than did subjects who lipread from one talker and then heard speech from a different talker.
The role of familiarity, semantic context, and amplitude-modulation on sentence intelligibility
Authors: Carrell Tom , Lewis Dawna
Published: October 2013

Amplitude modulation has been demonstrated to greatly improve the intelligibility of time-varying sinusoidal (TVS) sentences [Carrell and Opie, Percept. Psychophys. 52 (1992); Barker and Cooke, Speech Commun. 27 (1999); Hu and Wang, Proceedings of ICASSP-02 (2002)]. It has been argued that the improvement is due to a bottom-up process that causes the acoustically independent components of the sentences to be perceptually grouped for further analysis by the auditory system. A recent study [Shapley and Carrell, J. Acoust. Soc. Am. 118 (2005)] indicated that semantic information did not influence intelligibility levels of TVS or modulated TVS sentences. In virtually all other studies in which speech was distorted or degraded its intelligibility was improved by appropriate semantic context [Miller, et al., JEP 41 (1951)]. It is possible that listeners’ unfamiliarity with TVS speech might account for the difference. With one exception every study that has employed this type of stimulus provided the listener with very few practice sentences [Lewis, AAA (2005)]. The present experiment manipulated listeners’ familiarity with TVS sentences to test this notion. Participants were presented with high- and low-predictability TVS and modulated-TVS sentences. Familiarity had a large effect on perception and intelligibility. Interpretation of previous findings is reconsidered in this light.
On the relation of apparent naturalness to phonetic perceptual resolution of consonant manner
Authors: Remez Robert E. , Landau Claire A. , Ferro Daria F. , Meer Judith , Dubowski Kathryn
Published: October 2013

How does the qualitative experience of speech influence phonetic perception? Our perceptual studies of consonant place and voicing have revealed a dichotomous relation between phonetic sensitivity and naturalness. Auditory quality and phonetic sensitivity sometimes co-vary, while in other conditions phonetic sensitivity is indifferent to huge variation in naturalness. New tests are reported extending the research to the dimension of manner, a contrast correlated with qualitatively distinct acoustic constituents in normal production. Speech synthesis techniques were used to create naturalness variants through (1) variation in the excitation of a synthetic voicing source and (2) variation in the bandwidth of the formant centers. Listeners calibrated the relative naturalness of items drawn from the test series, and the acuity of perceivers to the contrast between fricative and stop manner was estimated with cumulative d′ across the series in identification tests. Combined with our prior findings, these new tests show how intelligibility and naturalness can be either perceptually orthogonal or contingent aspects of consonant dimensions, offering a tool to understand normative functions in speech perception. [Research supported by NIH (DC00308).]
Frequency effects in phoneme processing
Authors: Moates Danny R. , Watkins Noah E. , Bond Zinny S. , Stockmal Verna
Published: October 2013

Are phonological segments activated during word recognition in proportion to their frequency of use? Previous evidence for this hypothesis [Moates et al., Laboratory Phonology 7, edited by Gussenhoven and Warner (Mouton de Gruyter, 2002)] used a word reconstruction task. The present study used an online task, the gating task, in which progressively longer fragments of a word are presented to listeners who must identify the word in as few gates as possible. High- and low-frequency segments were contrasted by presenting them in word pairs that differed only in those two segments, e.g., label versus cable, where /l/ is used more frequently than /k/ [M. K. Vitevich and P. A. Luce, Behav. Res. Methods, Instrum. Comput. 36, 481–487 (2004)]. We constructed 30 pairs of two-syllable words for which the contrasting segments were at the first syllable onset, 30 more for the second syllable onset, and 30 more for the coda of a syllable. Identification judgments were gathered from 120 participants. t tests showed high-frequency segments to be identified at significantly earlier gates than their matched low-frequency segments for first onset and coda, but not second onset. These results offer further evidence for sublexical processes in spoken word recognition.
Perceptually balanced filter response for binaural dichotic presentation to reduce the effect of spectral masking
Authors: Kulkarni Pandurangarao N. , Pandey Prem C. , Jangamashetti Dakshayani S.
Published: October 2013

Earlier investigations show that the scheme of binaural dichotic presentation with spectral splitting of speech signal helps in reducing the effect of spectral masking for persons with moderate bilateral sensorineural hearing impairment. Speech perception improved by employing filters with interband crossover gain adjusted between 4 and 6 dB below the pass band gain. The relationship between scaling factors for a tone presented to the two ears, so that perceived loudness is that of a monaural presentation, is investigated for design of comb filters with improved perceptually balanced response. Results from the listening tests show that, for perceptual balance, the sum of the two scaling factors should be constant, indicating that the magnitude response of the comb filters should be complementary on a linear scale.
The organization of bilingual perceptual consonant space: English/Spanish bilingual perception of Malayalam nasal consonants
Authors: Silver Jenna , Harnsberger James
Published: October 2013

This study examines the capacity of English/Spanish bilinguals to discriminate between consonants that exist in only one of their respective phonetic inventories. Two non-native nasal consonant contrasts were tested: dental versus alveolar and the palatal versus velar, both found in Malayalam. The dental and palatal nasals appear in Spanish, while the alveolar and velar nasals occur in English. Poorer performance in discrimination was interpreted as indicative of a common nasal category subsuming the Spanish dental and English alveolar nasals; better performance was taken as evidence of the maintenance of separate categories from both languages. Two other tests were administered to aid in the interpretation of the discrimination test scores: forced-choice identification and perceptual similarity ratings. The findings of this research will be used to characterize the perceptual consonant space in terms of continuum between two possible bilingual systems: one that collapses similar categories across languages or one that maintains two distinct phonological systems that can be accessed simultaneously. It is believed that bilinguals will be able to discriminate between these contrasts more consistently than their monolingual peers; however, there is no prediction about performance relative to the monolingual group from Malayalam.
Agreement and reliability using reference-matching paradigm in perceptual voice quality rating in Chinese and English
Authors: Ho Mandy , Yiu Edwin
Published: October 2013

Perceptual voice judgment is commonly used in clinical voice quality evaluation. The use of a referencematching paradigm in perceptual ratings has been shown to improve both agreement and reliability (Yiu et al., in press). This study set out to investigate the agreement and reliability in rating Chinese and English dysphonic stimuli using the reference-matching paradigm. Experiment 1 aimed to synthesize Chinese and English dysphonic stimuli with different breathy and rough severity levels using the HLSyn Speech Synthesizer. Seven representative anchors (references) for each of the rough and breathy series in Chinese and English were chosen by three judges to be used in experiment 2. Acoustic analysis of the anchor series indicated they were of increasing severity. Experiment 2 recruited ten native Chinese and ten native English subjects to rate the quality of Chinese and English dysphonic voice samples using the synthesized anchor as references. Results showed that listeners achieved nearly 90% agreement in rating the Chinese stimuli and 80% agreement in rating the English stimuli regardless of their language background. The study showed that the reference-matching paradigm was a reliable method in rating dysphonic stimuli across listeners with different language backgrounds.
Learning to perceive non-native speech sounds: The role of test stimulus variability
Authors: Jantzen McNeel , Tuller Betty
Published: October 2013

Natural speech stimuli used in studies of phonological learning usually include several in talkers and phonetic environments because variability aids learning [e.g., Lively, Logan, and Pisoni, J. Acoust. Soc. Am. (1993)]. The present study investigated whether nonphonetic variability in the synthetic test set has a similar effect. First, a perceptual mapping procedure was performed using a synthetic continuum that ranged from the Malayalam voiced, unaspirated, dental stop consonant to the American English alveolar [d], with three F0 contours (low, mid, and high). Subjects identified the stimuli (2AFC) and judged their goodness as exemplars of each category. Subjects then received 15 sessions (one/day) of 2AFC training with feedback using natural stimuli produced by native Malayalam speakers, and performed difference ratings on a subset of pairs from the synthetic stimuli. The perceptual mapping procedure was repeated at 1 and 14 days post-training and results compared with a parallel experiment that included only the midlevel F0 contour in the synthetic test set. [Work supported by NSF.]