bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring changes of human airways by acoustical means
Authors: Pasterkamp Hans
Published: October 2013

The state of human airways is typically assessed by spirometry, i.e., by measuring airflow during maximum forced expiration. The required effort excludes subjects who cannot or will not perform such maneuvers. Turbulent airflow during normal breathing generates sound that can be recorded at the chest surface. Changes in airway caliber, e.g., by constriction or dilation, and concurrent changes in the tension of the airway walls affect the relation of airflow and breath sounds. This relation is complex and incompletely understood. However, the possibility to assess changes in the state of human airways by the relation of airflow and breath sounds promises an opportunity to develop auxiliary methods to spirometry. Two regions of the human airways have attracted the interest of researchers in respiratory acoustics. Breath sounds over the trachea (windpipe) increase in their airflow-specific intensity on narrowing of the upper airways, e.g., due to abnormal anatomy, infectious causes etc. Furthermore, spectral characteristics of tracheal sounds may indicate the region of abnormality. On the other hand, breath sounds over the chest change in their airflow-specific intensity with constriction of airways in the lung, e.g., due to asthma. It may therefore be possible to monitor the effectiveness of treatment by acoustical means.
Temporal evidence against the production of word-internal syllable structure
Authors: Redford Melissa A.
Published: October 2013

A production study examined whether the temporal pattern that cues onset cluster syllabification in English should be attributed to syllable structure per se or to coarticulatory processes that depend on segment identity and sequencing, but not on syllable structure. Experiment 1 tested for independent effects of syllable structure on intervocalic stop-liquid consonant duration. Three speakers produced stimuli in which sequence order, boundary strength, and stress were manipulated. The results showed that stimuli with word-internal sequences were produced with similar stop-liquid duration (S:L) ratios regardless of sequence order or stress. When a word boundary split the consonants, S:L ratios were much smaller, primarily because liquids were longer. Experiment 2 was aimed at distinguishing between alternate explanations for the pattern observed in Experiment 1. Data from three Russian speakers suggested that the English pattern was due to word-internal liquid reduction rather than to boundary lengthening. The S:L ratios in Russian were not affected by sequence order or boundary strength. Further, the ratios were significantly different from the word-internal S:L ratios of English, but not from the word-peripheral ones. Overall, the results argue against a causal relationship between syllable structure and articulatory timing, and for word-sized articulatory units in English.
Perception of coarticulated speech with contrastively enhanced spectrotemporal patterns
Authors: Wade Travis , Holt Lori
Published: October 2013

High-level contrastive mechanisms cause perception of auditory events to be influenced by spectral and temporal properties of surrounding acoustic context, and may play a role in perceptual compensation for coarticulation in human speech. However, it is unknown whether auditory contrast is incorporated optimally to compensate for different speakers, languages and situations or whether amplification of the processes involved would provide additional benefit, for example, in the perception of hypoarticulated speech, under adverse listening conditions, or in an incompletely acquired language. This study examines effects of artificial contrastive modification of spectrotemporal trajectories on the intelligibility of connected speech in noise by native and non-native listeners. Adopting methods known to improve automatic classification of speech sounds, we model contrast-providing context as an averaged estimated vocal tract function (LPC-derived log area ratio coefficient vector) over a Gaussian-weighted temporal window. Local coefficient values are adjusted from this context based on previously observed contrastive perceptual tendencies, and the intelligibility of the resulting speech is compared with that of unmodified trajectories across listener language backgrounds. Results are discussed with respect to implementation and applicability of general auditory processes.
Assimilation context effects as cue grouping phenomena
Authors: Couture Nicole , Godbois Sarah , Gow David W.
Published: October 2013

Listeners show bidirectional context effects in the perception of spontaneously assimilated speech. One account of these phenomena, feature cue parsing theory, suggests that both regressive and progressive context effects result from the same perceptual grouping process of aligning feature cues with assimilated word offsets and assimilating word onsets. This hypothesis was examined through two form priming experiments that explored the interpretation of spontaneously assimilated items under manipulations that either favored or disfavored the perceptual grouping of feature cues associated with assimilated and assimilating items. In both experiments, listeners heard phrases such as right berries in which a word final coronal segment (/t/) assimilated the non-coronal place of a subsequent word onset (labial /b/) to form an item that sounded like one of its lexical competitors (ripe). In Experiment 1 spatial continuity was manipulated through the use of same and different side lateralized presentation of assimilated words and their contexts. In Experiment 2 continuity in speaker identity was manipulated through cross-splicing. Analyses contrasted the pattern of priming found in continuous versus non-continuous contexts. The results are discussed in the terms of competing interpretations of assimilation context effects. [Work supported by the NIH.]
Relative contributions of feedback and editing in language production: Behavioral & articulatory evidence
Authors: McMillan Corey T. , Corley Martin , Lickley Robin J. , Hartsuiker Robert J.
Published: October 2013

Psychologists normally attribute the surfacing of phonological speech errors to one of two factors: editing of the speech plan [Levelt (1989)] or feedback between word and phoneme levels [Dell (1986)]. This paper assesses the relative contributions of each factor, focusing on the perception and articulation of elicited speech errors. Experiments one and two measure the likelihood of phonological exchange errors as a function of phonetic similarity [Frisch (1996)], using the SLIP paradigm and a tongue-twister task. Both experiments show that error likelihood increases with phonetic similarity between intended and actual utterance, an effect easy to account for in terms of feedback but not in terms of editing. Experiment three uses EPG to analyze the tongue-twister utterances: many errors occur at the articulatory level but are not easily perceived in the speech signal. Preliminary analysis suggests three patterns of error: (1) substitution of segments, which may be the result of editing; (2) simultaneous double articulation, hypothesized to be the result of residual activation due to feedback; and (3) overlapping double articulation, representing partial execution of one articulation before substitution with another. Taking these findings together, we hope to evaluate the relative contributions of editing and feedback to phonological speech errors.
Acoustical study of the development of stop consonants in children
Authors: Imbrie Annika K.
Published: October 2013

This study focuses on the acoustic patterns of stop consonants and adjacent vowels as they develop in young children (ages 2;6-3;3) over a six month period. Over forty different acoustic measurements were made on each utterance, including durational, amplitude, spectral, formant, and harmonic measurements. These acoustic data are interpreted in terms of the supraglottal, laryngeal, and respiratory actions that give rise to them. Data show that some details of the child’s gestures are still far from achieving the adult pattern. Significant findings include a high number of bursts in children’s stop productions, possibly due to greater compliance of the active articulator. The incidence of multiple bursts decreases over the period of the study. Measurements of the burst spectra show that the production of all three places of articulation is close to normal. Finally, children’s voiced stop productions display a delayed onset of voicing for all three places of articulation, indicating difficulty with coordination of closure of the glottis and release of the primary articulator. This measurement is found to decrease toward adult values over six months. Analysis of longitudinal data on young children will result in better models of the development of motor speech production. [Work supported by NIH grant DC00075.]
The perception of speech rhythm: An investigation of inter and intra rhythmic class variability using delexicalized stimuli
Authors: Dellwo Volker , Wagner Petra
Published: October 2013

It has been demonstrated that stress- and syllable-timed languages are differentiable in terms of parameters based on vocalic and consonantal interval durations, and that stress-timed languages are more variable in terms of these parameters. There is also significant between- and within-subject variability on these parameters, but it is unclear whether this production variability is perceptually salient in terms of rhythm. This issue was investigated in a series of experiments using delexicalized stimuli, in which the vocalic intervals were substituted by sinusoidal tones and the consonantal intervals by white noise. Subjects were asked to classify the stimuli according to the regularity of the tone sequences. The results thus far indicate that intra rhythm class variation, as measured by consonantal and vocalic interval duration variation, can be well perceived.
Palato-lingual contact patterns during Korean obstruent production; lax, aspirated and forced
Authors: Yoshioka Hirohide , Soone Kim
Published: October 2013

In Korean obstruents, there is a three-way distinction in manner of articulation; lax, aspirated and forced. The present study is to investigate the temporal and spatial details of tongue contacts with the hard palate during these three types of consonant production. The subject, a 30-year-old female of the Seoul dialect was instructed to read a set of various words beginning with these consonants, embedded in a frame sentence i-geo-/Cal/-ita (C=consonant). The palato-lingual contact patterns were recorded using dynamic electro-palatography. The results show that the area and duration of the palato-lingual contact are clearly different among these three types of consonants. As for stops, the palato-lingual contact is wider and longer in the forced stop production. In the affricate production, the patterns of the maximum contact area and the duration are as follows: wide and long in the forced type, middle in the aspirated, and narrow and short in the lax. These data strongly suggest that the temporal and spatial details of the palato-longual contact may play an important role in manifesting the Korean three-way distinction, together with other articulatory adjustments, such as laryngeal and respiratory controls.
Voice onset time is shorter in high-frequency words
Authors: VanDam Mark , Port Robert
Published: October 2013

Frequency of occurrence is known to have many effects on speech production [see J. Bybee, Phonology and Language Use (Cambridge, 2001)] including vowel quality, overall duration, rate of deletion, assimilation, coarticulation, etc. The current work addresses voice-onset time (VOT) in words with differing lexical frequency estimates from published materials and addresses whether words in a list exhibit similar effects to words in sentential context. Four talkers produced 20 low frequency words and 10 high frequency words four times each in isolation and again in non-idiomatic, sentential context. VOT was measured in monosyllabic content words with initial /t/. Results show that frequent words (e.g., talk, table) have a mean VOT roughly 10 ms shorter than less frequent words (e.g., talc, taint) (p<0.01). The effect was significantly stronger for words in a sentence (e.g., He will talk to his supervisor) than in a list. These findings are consistent with linguistic theories that propose detailed auditory representations for words and finely controlled productions, but are in conflict with traditional, abstract phonological representations.
Tension asymmetries in a finite element model of the vocal folds
Authors: Davidson Greg S. , Alipour Fariborz
Published: October 2013

Tension asymmetries in a finite element model of the vocal folds were examined as a function of lung pressure. The vocal fold model had an asymmetry in the tension ratio ranging from 1.1 to 2.0, corresponding to a 10%–100% increase in tension of the left fold compared to the right, and lung pressure was increased over the range 5–40 cm H2O. For tension ratios greater than 1.6, oscillation was not supported over most of this range. For tension ratios less than 1.6, the fundamental frequency was found to increase up to approximately 22 cm H2O. Mean vocal fold contact area showed a broad maximum over the range 8–13 cm H2O and decreased between 13 and 22–25 cm H2O. Open quotient decreased between 7.5 and 13–15 cm H2O and increased afterwards to reach a maximum value between 20 and 23 cm H2O. For these three parameters, the behavior above the upper thresholds was tension ratio dependent. Mean glottal area linearly increased with lung pressure with differing slopes over different pressure ranges. Taken together, the four parameters provide evidence for different vibratory domains. [Work supported by NIDCD grant No. DC03566.]
Underwater acoustic measurements with the Liberdade/X-Ray flying wing glider
Authors: D’Spain Gerald L. , Jenkins Scott A. , Zimmerman Richard , Luby James C. , Thode Aaron M.
Published: October 2013

An underwater glider based on a flying wing design (Jenkins et al., 2003) presently is under development by the Marine Physical Laboratory, Scripps Institution of Oceanography and the Applied Physics Laboratory, University of Washington. This design maximizes the horizontal distance between changes in buoyancy to minimize mechanical power consumed in horizontal transport. The prototype wing has a 6.1 m wing span and is 20 times larger by volume than existing gliders. Initial at-sea tests indicate that the lift-to-drag ratio is 17/1 at a horizontal speed of about 1.8 m/s for a 38-liter buoyancy engine. Beamforming results using recordings of the radiated noise from the deployment ship by two hydrophones mounted on the wing verify aspects of the prototype wing flight characteristics. The payload on the new glider will include a low-power, 32-element hydrophone array placed along the leading edge of the wing for large physical aperture at midfrequencies (above 1 kHz) and a 4-component vector sensor. Data previously collected by these types of arrays illustrate the performance of narrow-band detection and localization algorithms. Flight behaviors are being developed to maximize the arrays’ detection and localization capabilities. [Work sponsored by the Office of Naval Research.]
Adaptive rapid environmental assessment simulation framework
Authors: Wang Ding , Schmidt Henrik
Published: October 2013

The coastal environment is characterized by variability on small spatial scales and short temporal scales. These environmental uncertainties translate—in a highly non-linear fashion—into uncertain acoustic propagation properties, often severely affecting the sonar performance prediction capabilities. Conventional oceanographic measurement systems cannot capture these environmental uncertainties due to their limited predictability and the lack of mobility of the traditional measurement platforms. Taking advantage of the mobility of modern autonomous underwater vehicle technology, the Adaptive Rapid Environmental Assessment (AREA) concept has been developed to optimally use the available resources to capture the acoustic uncertainty by adaptive and rapid in situ measurement of the environmental properties most significant to the actual sonar system. The ocean area of interest is usually fairly large, and the in situ measurement resources are limited, and the adaptive sampling strategy in AREA can therefore make a significant difference in capturing and mitigating the sonar performance uncertainties. To determine an optimal or sub-optimal sampling strategy and test the optimization effect before doing costly on-site experiments, an Adaptive Rapid Environmental Assessment Simulation Framework (AREASF) has been developed, based on state-of-the-art forecasting frameworks and acoustic propagation models. The simulation framework has been applied to investigate the performance of AREA under different environmental conditions, and based on these results, the feasibility of performing real-time adaptive environmental assesment using AREA under realistic ocean conditions will be discussed. [Work supported by ONR.]
Auralization study of optimum reverberation for speech intelligibility for normal and hearing-impaired listeners
Authors: Yang Wonyoung , Hodgson Murray , Ezaki Maki
Published: October 2013

Reverberation and signal-to-noise level difference are two major factors affecting speech intelligibility. They interact in rooms. Past work has accounted for noise using a constant received background-noise level. Noise is actually generated by sources, and varies, and affects speech intelligibility differently, throughout the classroom, depending on where the sources are located. Here, a speech-babble noise source located at different positions in the room was considered. The relative output levels of the speech and noise sources, resulting in different signal-to-noise level differences, were controlled, along with the reverberation. The binaural impulse response of a virtual idealized classroom model was convolved with the Modified Rhyme Test (MRT) source and babble-noise signals in order to find the optimal configuration for speech intelligibility. Speech-intelligibility tests were performed with normal and hard-of-hearing subjects in each of 16 conditions which were combinations of reverberation time, signal-to-noise level difference, and speech- and noise-source locations. For both normal and hearing-impaired subjects, when the speech source was closer to the listener than the noise source, the optimal RT was zero. When the noise source was closer to the listener than the speech source, the optimal RT was generally non-zero. This agrees with theoretical results.
Social and academic implications of acoustically hostile classrooms for hard of hearing children
Authors: Jamieson Janet R.
Published: October 2013

The correlation between lowered academic achievement and classroom noise has been demonstrated for normally hearing children (Shield and Dockrell, 2003). However, the implications of poor classroom acoustics on the socialization and academic performance of children who are hard of hearing have not been examined. Eleven hard of hearing students in one school district, ranging from kindergarten to grade 7, were the foci of the present study. Acoustic measurements of each of the 11 classrooms in both unoccupied and occupied conditions revealed that all classrooms were acoustically challenging for the hard of hearing students, particularly at transition times, when ventilation was operational, and in the primary grades, when language learning needs are greatest. Interviews with parents and teachers underscored the difficulty these students experienced in comprehending teacher instructions and participating in group work. The students seldom initiated conversation or seatwork independently, but, rather, followed the lead of their peers. The hard of hearing students experienced frequent difficulties in understanding or participating in informal peer-to-peer conversations in the classroom, and parents and teachers attributed the children’s frequent social isolation and withdrawal at school to the combined effects of poor hearing abilities and hostile classroom acoustics. [Work supported by Hampton Research Fund.]
Split-beam sonar observations of targets as an aid in the interpretation of anomalies encountered while monitoring migrating adult salmon in rivers
Authors: Cronkite George M. W. , Enzenhofer Hermann J. , Gray Andrew P.
Published: October 2013

The experiments described in this paper relate known target configurations under controlled conditions to acoustic characteristics of multiple moving fish. This was done to increase the understanding of the interactions between targets and the effects these interactions have on the measurement of the number of salmon migrating in rivers. Multiple targets in various configurations were passed through a horizontally oriented 4×10 beam from a split-beam echo sounder. The effects on measurements of target strength, detection probability and target location in the beam are presented. There was a reduction in target detection due to the single-target selection criteria implemented by the hydroacoustic system. The conditions in a river were mimicked to demonstrate how a close range fish target may modify the beam geometry allowing detection of previously undetected targets. The effects of moving targets into radial alignment were demonstrated along with shadowing conditions that can cause extinction of target echoes.
Innovative techniques for analyzing the three-dimensional behavioral results from acoustically tagged fish
Authors: Steig Tracey W. , Timko Mark A.
Published: October 2013

Acoustic tags were used to monitor the swimming patterns of downstream migrating salmon smolts approaching various dams on the Columbia River, USA. Downstream migrating yearling chinook (Oncorhynchus tshawytscha), steelhead (Oncorhynchus mykiss), sockeye (Oncorhynchus nerka), and sub-yearling chinook smolts were surgically implanted with acoustic tags. Fish were tracked in three-dimensions as they approached and passed into the turbine intakes, spillways, and surface bypass channel entrances at the dams during the 2004 spring and summer outmigrations. A number of advances in the analysis techniques and software have been made over the past few years. Some of these improvements include the development of various fish density algorithms, stream trace modeling analysis, and advances of three-dimensional animation programs. Three-dimensional tracks of fish approaching the turbine intakes, spillways, and surface bypass channel entrances will be presented. Concentrations of fish passage will be presented as three-dimensional fish densities superimposed over dam structures. Stream trace modeling animation will be presented showing predicted fish passage routes.
The effect of shock wave treatment at the tendon-bone interface
Authors: Wang Ching-Jen
Published: October 2013

This study was performed to investigate the effect of shock wave treatment on the healing at tendon-bone interface. Thirty-six New Zealand White rabbits were used in this study. The anterior cruciate ligament was excised and replaced with the long digital extensor. The right knees (study group) were treated with 500 impulses of shock waves at 14 kV, while the left knees (control group) received no shock waves. Twenty-four rabbits were sacrificed at 1,2,4,8,12 and 24-week intervals. The specimens were studied with histomorphological examination and immunohistochemical stains for neovascularization and angiogenic growth factors. Twelve rabbits were sacrificed at 12 and 24 weeks for biomechanical analysis. The results demonstrated that the study group showed significantly more trabecular bone around the tendon and better bonding between bone and tendon as compared with the control group. The expressions of angiogenic growth factors were significantly higher in the study group than the control group. The tensile strength of the tendon-bone interface was significantly higher in the study group than the control group. In conclusion, shock wave treatment significantly improves the healing of the tendon-bone interface in a bone tunnel in rabbits. The effect of shock waves appears to be time-dependent.
Detecting cavitation in vivo from shock-wave therapy devices
Authors: Matula Thomas J. , Yu Jinfei , Bailey Michael R.
Published: October 2013

Extracorporeal shock-wave therapy (ESWT) has been used as a treatment for plantar faciitis, lateral epicondylitis, shoulder tendonitis, non-unions, and other indications where conservative treatments have been unsuccessful. However, in many areas, the efficacy of SW treatment has not been well established, and the mechanism of action, particularly the role of cavitation, is not well understood. Research indicates cavitation plays an important role in other ultrasound therapies, such as lithotripsy and focused ultrasound surgery, and in some instances, cavitation has been used as a means to monitor or detect a biological effect. Although ESWT can generate cavitation easily in vitro, it is unknown whether or not cavitation is a significant factor in vivo. The purpose of this investigation is to use diagnostic ultrasound to detect and monitor cavitation generated by ESWT devices in vivo. Diagnostic images are collected at various times during and after treatment. The images are then post-processed with image-processing algorithms to enhance the contrast between bubbles and surrounding tissue. The ultimate goal of this research is to utilize cavitation as a means for optimizing shock wave parameters such as amplitude and pulse repetition frequency. [Work supported by APL internal funds and NIH DK43881 and DK55674.]
The neural processing of musical instrument size information in the brain investigated by magnetoencephalography
Authors: Rupp Andre , van Dinther Ralph , Patterson Roy D.
Published: October 2013

The specific cortical representation of size was investigated by recording auditory evoked fields (AEFs) elicited by changes of instrument size and pitch. In Experiment 1, a French horn and one scaled to double the size played a three note melody around F3 or its octave, F4. Many copies of these four melodies were played in random order and the AEF was measured continuously. A similar procedure was applied to saxophone sounds in a separate run. In Experiment 2, the size and type of instrument (French horn and saxophone) were varied without changing the octave. AEFs were recorded in five subjects using magnetoencephalography and evaluated by spatio-temporal source analysis with one equivalent dipole in each hemisphere. The morphology of the source waveforms revealed that each note within the melody elicits a well-defined P1−N1−P2 AEF-complex with adaptation for the 2nd and 3rd note. At the transition of size, pitch, or both, a larger AEF-complex was evoked. However, size changes elicited a stronger N1 than pitch changes. Furthermore, this size-related N1 enhancement was larger for French horn than saxophone. The results indicate that the N1 plays an important role in the specific representation of instrument size.
Language acquisition after cochlear implantation of congenitally deaf children: Effect of age at implantation
Authors: Svirsky Mario , Holt Rachael
Published: October 2013

Evidence shows that early implantation of congenitally deaf children is beneficial. However, infants as young as 6 months of age have started to receive cochlear implants (CIs) in the USA. Such early implantation may be associated with higher risks, including anesthetic risk as well as the increased possibility of a false positive in the diagnosis of profound deafness. On the other hand, delaying implantation may be associated with the risk of missing windows of opportunity or sensitive periods for the development of communication skills. In this study, speech perception and language skills in children who received CIs in the first, second, third, or fourth year of life were compared. Participants were tested at regular 6-month intervals after implantation. The effects of several potential confounds were considered. In general, children implanted earlier outperformed those implanted later, with one exception: infants implanted at 6–12 months showed similar outcomes to children implanted at 12–24 months, at least through 2 to 2-1/2 years of age. This preliminary result may be associated with the difficulty of choosing appropriate stimulation parameters for infants, and its potential influence on the quality of the stimulation patterns delivered by the CI.
Acoustical case studies of three green buildings
Authors: Siebein Gary , Lilkendey Robert , Skorski Stephen
Published: October 2013

Case studies of 3 green buildings with LEED certifications that required extensive acoustical retrofit work to become satisfactory work environments for their intended user groups will be used to define areas where green building design concepts and acoustical design concepts require reconciliation. Case study 1 is an office and conference center for a city environmental education agency. Large open spaces intended to collect daylight through clerestory windows provided large, reverberant volumes with few acoustic finishes that rendered them unsuitable as open office space and a conference room/auditorium. Case Study 2 describes one of the first gold LEED buildings in the southeast whose primary design concepts were so narrowly focused on thermal and lighting issues that they often worked directly against basic acoustical requirements resulting in sound levels of NC 50–55 in classrooms and faculty offices, crosstalk between classrooms and poor room acoustics. Case study 3 is an environmental education and conference center with open public areas, very high ceilings, and all reflective surfaces made from wood and other environmentally friendly materials that result in excessive loudness when the building is used by the numbers of people which it was intended to serve.
Acoustic regulation of extracorporeal shock wave (ESW) therapy devices in the U.S
Authors: Maruvada Subha , Harris Gerald R.
Published: October 2013

The focused, large amplitude pressure fields produced by ESW lithotripsy devices were shown in the early 1980s to provide an efficient means for fragmenting urinary tract calculi. More recently, orthopedic applications of intense pressure pulses for pain relief and fracture healing have been developed. Under the US Medical Device Amendments of 1976, ESW therapy devices were deemed Class III, meaning that a pre-market application typically would be supported by both pre-clinical and clinical studies. This classification still applies, except for ESW lithotripters indicated for fragmenting kidney and ureteral calculi. These devices were reclassified to Class II in 2000, resulting in a simpler path to market in which a demonstration of substantial equivalence to a currently marketed device is sufficient. As part of its regulatory responsibility to address the safety and effectiveness of these devices, particularly with regard to acoustic output, the US Food and Drug Administration has recognized two International Electrotechnical Commission (IEC) standards for ESW lithotripters, one covering field measurements (IEC 61846) and the other dealing with labeling and other safety aspects (IEC 60601-2-36). Although these standards were designed primarily for lithotripsy, the FDA has used them where applicable in the regulatory analysis of other ESW therapy devices.
Working mechanism of extracorporeal shockwave therapy in non-urological disciplines
Authors: Schaden Wolfgang
Published: October 2013

For 32 years of extracorporeal shockwave lithotripsy (ESWL) only the mechanical strength of shockwaves were of clinical interest. For use in orthopaedics, the absence of dangerous long term effects (malignant degeneration, etc.) is the only important message. The mechanical model tries to explain the effect of shock waves by the provocation of microleasions in the tissue stimulating repairing processes. First doubts on this mechanical model came up when Schaden (2001) could show, that less energy is more efficient in the treatment of non-unions. Due to the basic research of the last years knowledge increased about the microbiological effects. Under the influence of shock waves the change of permeability of cell membranes and the liberation of free radicals was reported. Also the production of nitric oxide (NO) and different growth factors like vascular endothelial growth factor (VEGF), bone morphogenetic proteins (BMP), transforming growth factor-beta 1 (TGF-b1), insulin-like growth factor-I (IGF-I) etc. was observed. The biological model tries to explain the effect of shock waves by stimulating the ingrowth of blood vessels and liberation of growth factors. Under the influence of shock waves, biological tissues seem to be able to produce important substances to initiate healing processes.
Theoretical and experimental study of sound propagation in ducts with spatially periodic area changes
Authors: Nesbitt J. Ryan , Danilov Pavel V. , Bliss Donald B.
Published: October 2013

Sound propagation of one-dimensional waves through a tube with spatially periodic area changes is studied theoretically and experimentally. The resulting wave behavior is similar to that observed for periodic structures, with Bloch waves, pass-bands and stop-bands. The feasibility of this configuration is studied as a method to reduce sound radiation from noise sources having harmonics that fall in the stop bands. The performance of two such periodic passageways in series, each having different properties, is also studied. This approach to noise reduction is shown to give substantial attenuation. The bandwidth of the stop bands makes the design robust so that careful tuning is not required. Performance for broadband sound reduction is also evaluated. The relationship between area change parameters and the location and width of stop-bands is discussed. Experimental measurements show reasonable agreement with theoretical predictions as long as the actual geometry is accurately modeled.
The influence of low frequency energy on listener envelopment
Authors: Soulodre Gilbert A.
Published: October 2013

The importance of low frequencies to the perception of spatial impression in concert halls and multi-channel surround systems is well established. The present paper reports the results of a series of subjective tests that demonstrate the influence of low frequency lateral energy on the perception of listener envelopment. The results show that the laterally-arriving low frequency energy contributes significantly to listener envelopment, and new objective measures of listener envelopment are derived that account for this effect. The effect of the spatial distribution of low frequency energy on the perception of Bass is also discussed.
Sensitivity to intermodal asynchrony between acoustic and structural vibrations
Authors: Walker Kent , Martens William L.
Published: October 2013

The purpose of this study was to discover the attributes of musical stimuli which facilitate sensory integration in bi-modal music reproduction systems incorporating sound and whole-body vibration. It was hypothesized that subjective judgments regarding bimodal synchrony would vary depending on the spectral, temporal, and spatial properties of the stimuli. To test this hypothesis, musical instruments with significant low frequency energy and a variety of spectra-temporal envelopes were recorded. These stimuli were then reproduced with varying intermodal delay and overlap in frequency content between displayed vibratory and acoustic components. The air-born component of the bimodal stimuli was presented via a multichannel loudspeaker array, with a direct sound component, as well as a reproduced indirect sound arriving from all around the observer. Psychometric functions were constructed for time order judgment (TOJ) over a range of intermodal delay values. Changes in the slope and intercept of the transformed psychometric functions gave a clear picture of the influence of spectra-temporal and spatial parameters of the multimodal stimuli, the most striking results being the decreased tolerance for intermodal asynchrony associated with instruments recorded in reverberant environments. [Work supported by a Grant from VRQ of the Government of Quebec.]
Fear conditioning facilitates rats gap detection measured by prepulse inhibition of the startle reflex
Authors: Zou Dan , Wu Xihong , Li Liang
Published: October 2013

A low-intensity acoustic event presented shortly before an intense startling sound can inhibit the acoustic startle reflex. This phenomenon is called prepulse inhibition (PPI), and is widely used as a model of sensorimotor gating in both humans and animals. Particularly, it has been used for evaluating the aging effect on the mouse’s ability to detect a silent gap in otherwise continuous sounds. The present study extended this model to the emotional modulation of gap detection. The results show that a silent gap embedded in each of the two broadband noise sounds (55 dB SPL), which were delivered by two spatially separated loudspeakers, could inhibit the startle reflex that was induced by a loud sound presented from the third loudspeaker 50 ms after the gap. The inhibitory effect largely depended on the duration of the gap, with the mean duration threshold around 11 ms across 18 rats tested. Pairing the gap with foot shock in a temporally specific manner, but not in a temporally random manner, significantly reduced the duration threshold. Thus this study established a new animal behavioral model both for studying auditory temporal processing and for studying auditory signal-detection plasticity induced by emotional learning.
Application of musical timbre discrimination features to active sonar classification
Authors: Young Victor W. , Hines Paul C. , Pecknold Sean
Published: October 2013

In musical acoustics significant effort has been devoted to uncovering the physical basis of timbre perception. Most investigations into timbre rely on multidimensional scaling (MDS), in which different musical sounds are arranged as points in multidimensional space. The Euclidean distance between points corresponds to the perceptual distance between sounds and the multidimensional axes are linked to measurable properties of the sounds. MDS has identified numerous temporal and spectral features believed to be important to timbre perception. There is reason to believe that some of these features may have wider application in the disparate field of underwater acoustics, since anecdotal evidence suggests active sonar returns from metallic objects sound different than natural clutter returns when auralized by human operators. This is particularly encouraging since attempts to develop robust automatic classifiers capable of target-clutter discrimination over a wide range of operational conditions have met with limited success. Spectral features relevant to target-clutter discrimination are believed to include click-pitch and envelope irregularity; relevant temporal features are believed to include duration, sub-band attack/decay time, and time separation pitch. Preliminary results from an investigation into the role of these timbre features in target-clutter discrimination will be presented. [Work supported by NSERC and GDC.]
Temporal and spectral interaction in loudness perception
Authors: Pedersen Benjamin , Ellermeier Wolfgang
Published: October 2013

An experiment was conducted to investigate how changes in spectral content influence loudness judgments. Six listeners were asked to discriminate sounds, which were of one second duration and changing in level every 0.1 s. In one condition the first half of the sound was low-pass filtered and the second half high-pass filtered. In a second condition the opposite order was used. In a third condition no filtering was applied and the frequency spectrum was simply white noise. The results were analyzed using a statistical method, which assigns relative weights to the ten temporal segments. In this way individual weighting curves were obtained for each condition. Listeners tended to emphasize the beginning of the sound in their loudness judgments. When the frequency spectrum changed in the middle of the sound, however, the weighting of the onset of the new spectral content was emphasized as well. This outcome is inconsistent with overall temporal integration, and argues for a cognitive mechanism allocating attention to changes in an event sequence.
Production-perception relationships during speech development
Authors: Menard Lucie , Schwartz Jean-Luc , Boe Louis-Jean , Aubin Jerome
Published: October 2013

It has been shown that nonuniform growth of the supraglottal cavities, motor control development, and perceptual refinement shape the vowel systems during speech development. In this talk, we propose to investigate the role of perceptual constraints as a guide to the speakers task from birth to adulthood. Simulations with an articulatory-to-acoustic model, acoustic analyses of natural vowels, and results of perceptual tests provide evidence that the production-perception relationships evolve with age. At the perceptual level, results show that (i) linear combination of spectral peaks are good predictors of vowel targets, and (ii) focalization, defined as an acoustic pattern with close neighboring formants [J.-L. Schwartz, L.-J. Boe, N. Vallee, and C. Abry, J. Phonetics 25, 255–286 (1997)], is part of the speech task. At the production level, we propose that (i) frequently produced vowels in the baby’s early sound inventory can in part be explained by perceptual templates, (ii) the achievement of these perceptual templates may require adaptive articulatory strategies for the child, compared with the adults, to cope with morphological differences. Results are discussed in the light of a perception for action control theory. [Work supported by the Social Sciences and Humanities Research Council of Canada.]
Cross-language comparisons of contextual variation in the production and perception of vowels
Authors: Strange Winifred
Published: October 2013

In the last two decades, a considerable amount of research has investigated second-language (L2) learners problems with perception and production of non-native vowels. Most studies have been conducted using stimuli in which the vowels are produced and presented in simple, citation-form (lists) monosyllabic or disyllabic utterances. In my laboratory, we have investigated the spectral (static/dynamic formant patterns) and temporal (syllable duration) variation in vowel productions as a function of speech-style (list/sentence utterances), speaking rate (normal/rapid), sentence focus (narrow focus/post-focus) and phonetic context (voicing/place of surrounding consonants). Data will be presented for a set of languages that include large and small vowel inventories, stress-, syllable-, and mora-timed prosody, and that vary in the phonological/phonetic function of vowel length, diphthongization, and palatalization. Results show language-specific patterns of contextual variation that affect the cross-language acoustic similarity of vowels. Research on cross-language patterns of perceived phonetic similarity by naive listeners suggests that listener’s knowledge of native language (L1) patterns of contextual variation influences their L1/L2 similarity judgments and subsequently, their discrimination of L2 contrasts. Implications of these findings for assessing L2 learners perception of vowels and for developing laboratory training procedures to improve L2 vowel perception will be discussed. [Work supported by NIDCD.]
Training Japanese L2 learners to perceive difficult American vowel contrasts
Authors: Sperbeck Mieko , Strange Winifred , Ito Kikuyo
Published: October 2013

This study compared two methods to improve perception of three vowels ae, ah, uh and examined generalization of training to new vowels eh, awe and to trained vowels by new speakers in new consonantal contexts and in real words. One training protocol began with hVba disyllables (sessions 1–4) and then introduced sentence-length utterances with vowels in gabVpa/gadVda trisyllables (sessions 5–9). The other protocol used sentence materials in all 9 sessions. Twenty-four participants were divided into the two training conditions; half of each group were relatively inexperienced while the others were more experienced. Identification pretests on the 5 vowels in sentence materials showed no differences in overall accuracy for inexperienced (51% correct) and experienced groups (54% correct). Post-tests showed that perception of trained vowels improved in both trained and non-trained trisyllable/sentence materials (65% correct for both training groups). There were no significant differences in amount of improvement for inexperienced and experienced participants. Training also led to improvement on trained vowels by new speakers in new contexts and to real words. However, performance on non-trained vowels did not improve (actually decreased for eh) suggesting a response bias in post-test identification performance. [Work Supported by NIH.]
The acquisition of Taiwan Mandarin vowels by native American English speakers
Authors: Lin Cyun-jhan
Published: October 2013

Previous work on the production of English and French phones by native American English speakers indicated that equivalence classification prevent L2 learners from approximating L2 phonetic norms of similar phones and that learning French would not affect English speakers’ production of L1 similar phone /u/ (Flege, 1987). In this study, there were five subjects, including 2 advanced native American English learners of Taiwan Mandarin, 2 basic native American English learners of Taiwan Mandarin, and 1 monolingual Taiwan Mandarin speaker. The corpus were 12 English words ‘‘heed, who’d, hod; leak, Luke, lock; beat, suit, bot; peat, suit, pot,’’ and 12 Mandarin words [i,u, a; li, lu, la; pi, pu, pa; phi, phu, pha]. Both advanced and basic learners’ production of English and Mandarin words and monolingual Taiwan Mandarin speaker’s production of Mandarin words were directly recorded onto a PC. Vowel formants were taken from spectrograms generated by Praat. Preliminary results showed the vowel space of advanced learners between Taiwan Mandarin [i] and [u] was larger than that of basic learners, and closer to the Taiwan Mandarin norms. Besides, the vowel space between English [i] and [u] by basic learners was dramatically smaller than that of American English norms.
Evolution of the speech intelligibility of prelinguistically deaf children who received a cochlear implant
Authors: Bouchard Marie-Eve , Cohen Henri , LeNormand Marie-Therese
Published: October 2013

The 2 main objectives of this investigation are (1) to assess the evolution of the speech intelligibility of 12 prelinguistically deaf children implanted between 25 and 78 months of age and (2) to clarify the influence of the age at implantation on the intelligibility. Speech productions videorecorded at 6, 18 and 36 months following surgery during a standardized free play session. Selected syllables were then presented to 40 adults listeners who were asked to identify the vowels or the consonants they heard and to judge the quality of the segments. Perceived vowels were then located in the vocalic space whereas consonants were classified according to voicing, manner and place of articulation. 3 (Groups) ×3 (Times) ANOVA with repeated measures revealed a clear influence of time as well as age at implantation on the acquisition patterns. Speech intelligibility of these implanted children tended to improve as their experience with the device increased. Based on these results, it is proposed that sensory restoration following cochlear implant served as a probe to develop articulatory strategies allowing them to reach the intended acoustico-perceptual target.