bluuebunny/crossref_metadata_2025 huggingface dataset:
Disposable device for human plateletpheresis
Authors: Gu Yuyang , Chen Chuyi , Wang Zeyu , Huang Po-Hsun , Fu Hai , Huang Tony Jun
Published: April 2018

Plateletpheresis is a crucial step for the blood donation and clinical diagnosis. Herein we demonstrate a method to conduct plateletpheresis using acoustofluidic technology in a disposable device that is fabricated solely by a plastic material with precise simulated modeling using low-cost technic. In this device, a quarter wavelength resonator is utilized in order to serve the top layer as the 'tracking wall.' With this device, over 87% RBC removal and platelet recovery rate are achieved at 20 mL/min flow rate with undiluted whole human blood while the function of the platelets is still retained and better than conventional plateletpheresis method. Conclusively, this disposable device synthesizes the high efficiency, high throughput and high biocompatibility which is suitable as the substitute of the current plateletpheresis equipment.
Audio-haptic perception in immersive improvisational environments
Authors: Van Nort Doug
Published: April 2018

This presentation describes a recent study that explored audio-haptic perception in group performance contexts. Vocalizing and listening activities were structured using methods from the Deep Listening practice developed by Pauline Oliveros, with augmentations to the immersive environment made using a multi-channel audio system, in combination with under-floor and body-worn vibrotactile transducers. Bio-signals from participants were captured and qualitative feedback solicited in order to understand the perceptual and physiological effects of introducing signals to these structured performative activities that are dynamically spatialized in audio as well as haptic sense modalities. The study compares the differences in response when these signals are driven by an external source in comparison to being driven by the bio-signals of participants, including measures focused on convergence and divergence of bio-phyiscal activity. The presentation will compare these scenarios and discuss the larger implications for developing immersive interactive environments that contribute to a sense of connection, sociality and play.
Allpass decorrelating filter design and evaluation
Authors: Canfield-Dafilou Elliot K. , Abel Jonathan S.
Published: April 2018

By breaking up the phase coherence of a signal broadcast from multiple loudspeakers, it is possible to control the perceived spatial extent and location of a sound source. This so-called signal decorrelation process is commonly achieved using a set of linear filters, and finds applications in audio upmixing, spatialization, and auralization. It is important that any individual decorrelating filter does not perceivably alter the sound of its input, i.e., that it does not color the signal spectrum or smear transients over time. In that way, the process will only affect the spatial properties of the sound. Allpass filters make ideal decorrelation filters since they have unit magnitude spectra, and therefore can be perceptually transparent. By manipulating their phase, allpass filters can be leveraged to achieve a degree of decorrelation. Here, we present a method for designing allpass decorrelation filters by specifying group delay trajectories in a way that allows for control of the amount of correlation as a function of frequency. This design is efficiently implemented as a cascade of biquad allpass filters. We present statistical and perceptual methods for evaluating the amount of decorrelation and audible distortion.
Impulse noise measurements of M16 rifles at Quantico Marine Base
Authors: Rasband Reese D. , Wall Alan T. , Gee Kent L. , Swift S. Hales , Wagner Caleb M. , Murphy William J. , Kardous Chucri A.
Published: April 2018

This paper describes a study conducted at U.S. Marine Corps Base Quantico to determine firing range impulse noise levels and assess noise exposures. Measurements were performed with M16 rifles at an outdoor firing range using a 113-channel array of 6.35 and 3.18 mm microphones that spanned potential locations for both shooters and instructors. Data were acquired using 24-bit cards at a sampling rate of 204.8 kHz. Single weapon measurements were made with and without an occupied range, with a shooter and with a remotely triggered gun stand. In addition, measurements were made with multiple shooters to simulate exposures for a realistic range environment. Results are shown for the various range configurations as a function of angle and distance. Analyses include waveforms, spectra, and peak levels, as well as the 100 ms A-weighted equivalent levels required by military standard MIL-STD-1474E. [Sponsored by US Office of Naval Research.]
Rating the perception of jet noise crackle
Authors: Russavage Paul B. , Neilsen Tracianne B. , Gee Kent L. , Swift S. Hales
Published: April 2018

Crackle is a perceptual aspect of noise caused by impulsive acoustic shocks and observed in supersonic jets, including those from military aircraft and rockets. Overall and long-term spectral noise metrics do not account for the unique perception of crackle. Listening tests were designed to better understand perception of crackle and examine its relationship to physical noise metrics, such as skewness of the first time derivative of the pressure waveform, hereafter derivative skewness. It is hypothesized that as derivative skewness increases, the perception of crackle tends to increase. Two listening tests were conducted with 30 subjects to examine their perception of crackle. In the first test, subjects compared and ordered crackle-containing sounds. In the second test, category scaling was employed with subjects rating the crackle content with category labels: (1) smooth noise with no crackle, (2) rough noise with no crackle, (3) sporadic crackle, (4) continuous crackle, and (5) intense crackle. There is a high correlation between perception of crackle and derivative skewness. This five-point classification scheme appears to be an effective tool to measure crackle perception. These insights will help inform community noise models, allowing them to incorporate annoyance due to jet crackle. [Data courtesy of F-35 JPO.]
Sonic boom induced window rattle in indoor environments
Authors: Klos Jacob
Published: April 2018

The perceptual environment inside homes ensonified by sonic booms consists mainly of the transmitted indoor boom sound, rattle from items in loose contact with vibrating structures, and structural vibrations that may be felt or seen. In this presentation, measurements of window rattle from a recent laboratory study conducted inside the Interior Effects Room at NASA Langley Research Center will be summarized. Low amplitude sonic booms were reproduced at the facility exterior, which induced rattle in several distressed windows that were interchanged in the facility wall. The indoor sound field, the combined transmitted boom and window rattle sound, was measured at seven microphones placed inside the test room. The “rattle only” sound was recovered by subtracting the “boom only” sound, which was computed by convolving a measured room impulse response with the exterior excitation waveform, from each microphone measurement. In total, predicted low booms from fourteen different vehicles, each at three loudness levels, ensonified forty-two different window rattle conditions. Each measurement was repeated six times in both a lively and damped room configuration. This database of 148,176 rattle measurements enabled objective comparisons of rattle produced by different aircraft, at different booms levels and for different window rattle conditions.
Effects of self-generated noise on quiet threshold by transducer type in school-age children and adults
Authors: Porter Heather , Leibold Lori , Buss Emily
Published: April 2018

This study tested the hypothesis that higher levels of self-generated noise in children results in larger child-adult differences for the detection of low-frequency sounds when testing is conducted using transducers associated with a pronounced occlusion effect. Detection thresholds were measured at 125, 250, 500, and 1000 Hz using standard clinical procedures with supra-aural headphones, insert earphones, or a loudspeaker. Probe microphone recordings were made during testing with each transducer. Listeners were 4.5- to 11-year-olds, and adults. Preliminary results are consistent with the a priori hypothesis. For all listeners, thresholds at 125 and 250 Hz were highest with supra-aural headphones and lowest with free-field presentation. This transducer effect was most pronounced for younger children. Child-adult differences were smaller at 500 and 1000 Hz, an observation consistent with reduced effects of self-generated noise with increasing frequency. Trial-by-trial analysis of probe microphone recordings will be presented.
Mitigating the effects of reverberation and noise in cochlear implants
Authors: Chu Kevin M. , Throckmorton Chandra S. , Collins Leslie M. , Mainsah Boyla O.
Published: April 2018

In listening environments with room reverberation and background noise, cochlear implant (CI) users experience substantial difficulties in understanding speech. Because everyday environments have different combinations of reverberation and noise, there is a need to develop algorithms that can mitigate both effects to improve speech intelligibility. Desmond et al. (2014) developed a machine learning approach to mitigate the adverse effects of late reverberant reflections of speech signals by using a classifier to detect and remove affected segments in CI pulse trains. In this study, we investigate the robustness of the reverberation mitigation algorithm in environments with both reverberation and noise. We conducted sentence recognition tests in normal hearing listeners using vocoded speech with unmitigated and mitigated reverberant-only or noisy reverberant speech signals, across different reverberation times and noise types. Improvements in speech intelligibility were observed in mitigated reverberant-only conditions. However, mixed results were obtained in the mitigated noisy reverberant conditions as a reduction in speech intelligibility was observed for noise types whose spectra were similar to that of anechoic speech. Based on these results, the focus of future work will be to develop a context-dependent approach that activates different mitigation strategies for different acoustic environments. [Research supported by NIH grant R01DC014290-03.]
Utilizing cross-channel features for reverberation mitigation in cochlear implants
Authors: Shahidi Lidea K. , Throckmorton Chandra S. , Collins Leslie M. , Mainsah Boyla O.
Published: April 2018

Cochlear implant (CI) users experience difficulties in understanding speech in reverberant environments as both active speech and non-informative speech segments of the reverberant signal are incorporated into the CI stimulus pattern. The non-informative speech segments are due to late reverberant signal reflections and are referred to here as overlap-masking segments. Desmond et al. (JASA, 2014) showed that removal of all overlap-masking segments from the CI stimulus pattern significantly improved the intelligibility of reverberant speech in CI users. Desmond (2014, Ph.D. dissertation) proposed a reverberation mitigation strategy based on training a machine learning classifier to identify and delete overlap-masking segments in CI pulse trains. The mitigation strategy employed within-channel features to mitigate overlap-masking effects in a given electrode channel. However, since adjacent electrode channels tend to enter the overlap-masking state concurrently, additional information about the state of other channels might provide useful information for classification. In this work, we explore the use of cross-channel features to improve classification performance. We find significant improvements in classification performance in low-frequency electrode channels after the addition of cross-channel features. Preliminary results from normal-hearing listeners performing speech recognition tests using vocoded speech under simulated reverberation will be reported. [Research supported by NIH grant R01DC014290-03.]
Estimating the relative interaural place mismatch for bilateral cochlear-implant listeners
Authors: Stakhovskaya Olga A. , Bernstein Joshua G. , Jensen Kenneth K. , Goupell Matthew
Published: April 2018

Frequency-matched bilateral input is important for the optimum encoding of binaural cues to facilitate sound localization, auditory scene analysis, and speech understanding in noise. Current bilateral cochlear-implant (CI) programming procedures do not account for potential interaural place-of-stimulation mismatch. This study investigated whether a perceptual test of interaural-time-difference (ITD) sensitivity can effectively estimate relative interaural mismatch for bilateral CI listeners. Ten bilateral CI listeners were tested on a two-interval left-right ITD discrimination task. Loudness balanced 300-ms, 100 pulse-per-second constant-amplitude pulse trains were delivered to single-electrode pairs using direct stimulation. Measurements were made for five reference electrodes evenly distributed along the array in one ear, and for at least five closely spaced comparison electrodes in the other ear for each reference electrode. The pair with the smallest thresholds was assumed to be the most closely place matched. ITD sensitivity was variable across listeners, with thresholds ranging from 80-2000 μs. ITD tuning curves varied across and within listeners, ranging from widths of approximately one (sharp tuning) to eight electrodes (broad tuning). While cases with narrower tuning provide clear suggestions for frequency programming to minimize interaural mismatch, estimates of mismatch were difficult to ascertain for cases with broad tuning.
Effects of age on the discrimination of modulation type for 2- and 10-Hz rates
Authors: Moore Brian C. , Mariathasan Sashi , Sek Aleksander
Published: April 2018

Frequency modulation (FM) at a rate of 10 Hz may be detected via conversion of FM to amplitude modulation (AM) in the cochlea, while 2-Hz FM may be detected partly using temporal fine structure (TFS) information. Greater age may impair the processing of TFS information while sparing the processing of AM information. To test these ideas, while controlling for the effects of detection efficiency, a two-stage experiment was conducted. In stage 1, psychometric functions were measured for the detection of AM alone and FM alone imposed on a 1000-Hz carrier, using 2- and 10-Hz rates. In stage two, the task was to discriminate AM from FM at the same modulation rate when the detectability of the AM alone and FM alone was equated. For young normal-hearing subjects, discrimination was markedly better for the 2-Hz than for the 10-Hz rate, consistent with the idea that FM is coded in a different way from AM at 2 Hz. For older subjects with normal hearing at 1000 Hz, a similar pattern was obtained, but discrimination of AM from FM at 2 Hz was somewhat poorer than for the young normal-hearing subjects, consistent with an age-related reduction in ability to use TFS cues.
Word recognition for regional dialects and nonnative accents in children and adults: Influence of psycholinguistic distance
Authors: Holt Rachael F. , Bent Tessa , Katherine Miller E. , Skratt Henry Mone , Martin Melissa M. , Jamsek Izabela A. , Green Donna E.
Published: April 2018

Few studies have directly compared adults' or children's perception of nonnative accents and unfamiliar regional dialects. However, some evidence suggests that nonnative varieties cause greater decrements in intelligibility and processing than unfamiliar native dialects, while metalinguistic awareness for nonnative varieties develops earlier than awareness for regional variants. To directly examine regional and nonnative accent perception, we tested sentence recognition in American-English monolingual 5- to 7-year-old children and adults for three accents: Central Midland (familiar native), Scottish (unfamiliar native), and German (detectable but mild nonnative accent) in quiet and multitalker babble. In quiet, both children and adults showed highly accurate word recognition for all accents. Although children's performance was lower than adults’ in noise, overall word recognition accuracy patterns across accents were similar: accuracy was highest for the Midland talker, followed by the German-accented talker, and poorest for the Scottish talker. These data suggest that the greater decrements for nonnative accents compared to unfamiliar regional dialects previously reported may have arisen from the specific varieties or talkers selected. Although both types of unfamiliar speech can cause listening difficulty in noisy environments, the acoustic-phonetic distance from the home dialect may predict both adults' and children's performance better than native vs. nonnative status.
The influence of lexical characteristics and talker accent on the recognition of English words by speakers of Korean
Authors: Choi Minkyoung , Holliday Jeffrey J. , Munson Benjamin
Published: April 2018

A growing body of evidence that the influence of phonological neighborhood density (PND) on speech perception increases over the course of second language (L2) learning (e.g., Bradlow et al., 1999; Imai et al., 2005; Yoneyama & Munson 2017). This was first shown by Imai et al. (2005), who found that only high-proficiency Spanish-speaking L2 English-language learners (ELL) showed an influence of English PND on speech perception; low-proficiency ELLs did not. More recently, Yoneyama and Munson (2017) examined whether Imai et al.’s findings could be replicated with ELLs whose L1 was Japanese. In contrast to Imai et al., Yoneyama and Munson found that there were strong effects of PND on word recognition for all three groups of subjects: low-proficiency ELLs (tested in Japan), high-proficiency ELLs (tested in the US), and native speakers of English. The contrast between Imai et al. and Yoneyama and Munson’s findings suggests that a wider set of studies using many different L1-L2 mismatches are needed to understand the range of PND effects in L2 learning. The current study examines Korean-speaking L2 learners of English using the same methods as Imai et al. and Yoneyama and Munson. Testing is ongoing in the US and Korea.
Identifying /l/ and /n/ in English by multi-dialectal speakers of Mandarin
Authors: Li Bin
Published: April 2018

Native speakers of Standard Mandarin are mostly proficient in their local dialects which were acquired at home before or parallel to the Standard Mandarin. The Mandarin dialects that share general grammar mainly differ in their phonological features. A well-known example is the contrast of /l/ and /n/, which is not fully maintained or completely absent in many southern Mandarin dialects. This study investigated how perception of the English consonantal contrast may be influenced by experience in Mandarin dialects with varying phonemic status and distribution of the sounds. We examined the identification of the two consonants in various phonetic environments by Chinese bi-dialectal speakers who were all advanced learners of English-as-a-foreign-language. Results confirmed predicted perceptual difficulties across dialect groups as well as revealed other phonetic factors affecting the perceptual accuracy.
Disruption of learning on a non-native phonetic contrast by a brief practice break
Authors: Little David F. , Wright Beverly
Published: April 2018

What is required for long-lasting learning of a non-native phonetic contrast? Do principles from fine-grained discrimination learning apply? Discrimination learning often requires extensive practice within a day for performance to improve across days, and a 30-minute break midway through practice can disrupt that learning. Thus it appears that trials must integrate to a learning threshold in a transient memory store in order for durable discrimination learning to occur. We asked whether this same principle applies in phonetic-contrast learning. To do so, we trained monolingual speakers on a non-native phonetic contrast along a voice-onset-time (VOT) continuum. Those who engaged in a single continuous practice session on day 1 reached above chance accuracy on day 2 while classifying the non-native phoneme. In contrast, when day-1 practice included a 30-minute break halfway through training, day-2 performance was at chance. These results suggest that for phoneme learning, as for discrimination learning, long-lasting learning requires that practice trials be integrated up to a learning threshold within a transient memory store before they are sent en masse into a memory that lasts across days.
Cross-modality interference effects of phonetic and prosodic information in second language learners
Authors: Kao Chieh , Zhang Yang
Published: April 2018

Successful communication relies on efficient use of information from multiple modalities and dimensions. Our previous research using a cross-modal priming paradigm showed that congruent visual primes facilitate faster recognition of phonetic and emotional prosodic information in speech. Event-related potential (ERP) data further revealed distinct brain mechanisms in the N400 and late positive response (LPR) components for processing linguistic and paralinguistic congruency. The current study extended the same paradigm to English-as-a-second-language (ESL) learners to examine possible interference between the two informational dimensions as a function of language experience. Participants were sixteen normal adult ESL learners. Monosyllables /bab/ and /bib/ in a happy or angry tone were used as the auditory stimuli, and pictures of the speaker articulating vowel /a/ and /i/ with a happy or angry facial expression were used as the visual primes. Compared to native English speakers, ESL learners showed significantly longer reaction time with inconsistent congruency effects in both conditions. But their behavioral accuracy data mirrored those of the native speakers, and native-like N400 and LPR components were also reliably elicited in the ESL group in both conditions. Together, these results indicate stronger cross-modal interference between phonetic and emotional prosodic information in speech for second language learners.
Does it have to be correct?: The effect of uninformative feedback on non-native phone discrimination
Authors: Olmstead Annie J. , Viswanathan Navin
Published: April 2018

Learning the phonetic inventory of a non-native language requires perceptual adjustment to non-native phones that sometimes belong to a single category in the learner’s native language. For example, English native speakers often struggle to learn the distinction between the Hindi phonemes [ʈ] and [t̪] that are both categorized as [t] in American English (AE). Olmstead and Viswanathan (2017) showed that AE listener’s discrimination of these non-native phones could be improved using short exposure to naturally produced Indian English (IE) words that contained the target contrast. In the current study, we examine how feedback affects this lexical retuning effect. Specifically, we set up feedback schedules that either reinforce the consistent mapping of these consonants onto the AE speaker’s existing [t] and [θ], or that reinforce an inconsistent mapping. If the consistency of this mapping in IE is paramount to improving phonetic discrimination, then reinforcing it should strengthen the effect and providing a variable mapping should weaken it. Results suggest that the feedback given to participants did not change the effect on discrimination—discrimination improved whether or not the feedback was consistent. Implications of these findings are discussed.
Speech enhancement and speaker verification with convolutional neural networks
Authors: Guzewich Peter , Zahorian Stephen
Published: April 2018

Convolutional neural networks have been used with great success for image processing tasks. The convolution filters can act as powerful feature detectors in images to find edges and shapes. Time domain speech signals are one dimensional, but frequency domain information can be viewed in the same way as an image, allowing one to use two-dimensional convolutional networks for tasks such as speech enhancement. In this paper, recently reported deep neural network preprocessing methods used for dereverberation are examined to explore their ability to remove noise and or reverberation. A convolutional network is then introduced and compared to the previous methods to explore the relative strengths and weaknesses of each approach. Comparisons are made through experimentation in the context of speech quality and speaker identification tasks.
An effective method of choosing vertical beam pitch angle of sonar array
Authors: He Mengnan , Zhan Fan , Liang Guolong , Shen Ao
Published: April 2018

In order to obtain a better array gain, the sonar main-beam should point to the incident direction of acoustic waves. For stereoscopic sonars, such as cylindrical array sonar, the incident direction of acoustic wave contains both horizontal angle and vertical pitch angle (VPA). Due to the variation of acoustic VPA caused by hydrological condition, the array gain would decrease seriously when the VPA of sonar beam doesn't match the VPA of acoustic waves. To solve the above problem, we proposed a VPA optimization method for stereoscopic sonars. First,we analyzed the variation rule of both sonar array gain and the acoustic VPA. Then,search for the VPA of the sonar beam in the vertical directions by beam scanning, so as to maximize the array gain. Simulations results are provided to validate the performance of the proposed method.
Generalized likelihood ratio test based on mode-space beamfoming with a horizontal line array
Authors: Zhang Yifeng , Zou Nan , Wang Jinjin , Feng Jia
Published: April 2018

The conventional detection method has difficulty in detecting the narrowband signal in the noisy shallow water waveguide, because detection under the plane-wave model mismatches the shallow water waveguide. In this paper, a generalized likelihood ratio test based on mode-space beamfoming is proposed, considering the acoustic field in a shallow water waveguide can be characterized by normal mode model. Due to the otherness of the mode wavenumbers, the generalized likelihood ratio test model is constructed by mode-space beamforming. As the mode-space beamfoming has an ill-posed problem, we ignore the small eigenvalues of the coefficient matrix, and then has a benefit on the performance of detector. Theoretical analysis and simulation result validate the effectiveness of the proposed algorithm.
An ultrafast broadband digital signal processing approach to pulse echo measurements
Authors: Sturtevant Blake , Sinha Dipen N. , Pantea Cristian
Published: April 2018

Pulse-Echo (PE) measurements are commonly used to determine the sound velocity in a sample of known length. In PE measurements, the interface between the transducer and buffer rod, and that between the buffer rod and sample, introduces a total phase shift, Φ, to the acoustic wave that must be accounted for if high accuracy in the velocity is desired. The appropriate time correction, τ=Φ/ω, is traditionally determined by measuring the time-of-flight of multiple acoustic waves with different angular frequencies, ω. A single PE measurement can take several minutes, depending on experimental details such as the number of frequencies measured and the amount of signal averaging performed. Several minutes of data acquisition is tolerable for static experiments, but it is too long for many dynamic processes of interest in biology, pulsed magnetic fields, or any other rapidly changing system. This work describes an approach to PE in which a single broadband signal is collected and later processed offline using standard digital signal processing techniques. We demonstrate that a single captured waveform can be processed to yield the same information as 80 separate waveforms collected over an 80 MHz span, enabling accurate PE measurements on sub-second time scales.
Two-point statistics of synthetic three-dimensional polycrystalline microstructures
Authors: Norouzian Musa , Turner Joseph A.
Published: April 2018

The two-point spatial statistics of a heterogeneous material are crucial in ultrasonic attenuation and backscatter calculations. In this presentation, several common assumptions used for modeling polycrystals are examined. In most studies, the spatial and tensorial elements of the covariance function are assumed to be decoupled. Also, two-point correlation models often assume a single effective grain size for polycrystalline materials and a spatial correlation function that has an exponential decay at a rate directly proportional to the average grain diameter. This investigation uses the Dream.3D software platform to generate three-dimensional (3D) realizations of polycrystalline materials in order to study their two-point statistics. Using lognormal distributions with fixed means but different widths, a variety of different polycrystalline microstructures are simulated. The results show that the spatial correlation function is directly influenced by the grain size distribution. For a fixed mean grain size, wider distributions exhibit longer range correlations than narrower ones. The results also show that decoupling of the tensorial and spatial elements of the covariance function may not be valid for all lognormal grain size distributions. These results are anticipated to have an important impact on ultrasonic attenuation and backscatter models. [Research supported by AFRL under prime contract FA8650-15-D-5231.]
Uncertainty bounds on ultrasonic phase velocities for polycrystalline media
Authors: Norouzian Musa , Turner Joseph A.
Published: April 2018

Most theoretical work related to the study of the effective properties of polycrystals assume infinite media with randomly oriented grains. Therefore, the bulk material has absolute isotropy. However, real samples always include a finite number of grains such that the inspection volume will have some associated anisotropy. Hence, bounds on the bulk properties can be expected for a given measurement. In this work, the effect of the number of grains on this anisotropy variation is studied using Dream.3D software. The effective elastic modulus tensor is derived using Voigt, Reuss, and self-consistent techniques with 1700 microstructures comprised of equiaxed cubic grains in 17 different volumes. The bond transformation is utilized to quantify the standard deviation of the average elastic modulus. The standard deviations of several materials are shown to be inversely proportional to the square root of the number of grains. Based on the single-crystal anisotropy, a master curve is derived which relates modulus anisotropy to the number of grains. In addition, Christoffel equation is used to study the relevant phase velocities. With appropriate normalization, a similar master curve is derived. Such results will have important impacts on ultrasonic models associated with metals. [Research supported by AFRL under prime contract FA8650-15-D-5231.]
A study on the comparison of characteristics between blower and sound fire extinguisher
Authors: Bae Seonggeon , Bae Myungjin
Published: April 2018

In general, the characteristics of the blower used for cleaning and the characteristics of the sound fire extinguisher have the same point that they use wind. However, unlike a blower that allows the wind to clean by the wind, a sound extinguisher is a principle that turns off the fire by blocking the air of oxygen necessary for ignition in the air. This study was carried out by separating the two features.
The effects of prosody on pitch and voice quality of White Hmong tones
Authors: Garellek Marc , Esposito Christina M.
Published: April 2018

White Hmong contrasts two high-falling tones (one breathy, the other modal) and two low tones (one modal level-tone, the other creaky low-falling). Perceptual studies [Garellek et al. (2013)] have shown that listeners rely on breathy voice to distinguish between the high-falling tones, but ignore creaky voice when distinguishing between the low tones. We test whether such differences stem from prosodic variation, by examining tokens from stories read by native speakers. Vowels were annotated for phrasal position and neighbouring tones. We obtained f0 and voice quality measures. Results support and help elucidate previous perceptual research: (1) the breathy high-falling tone is breathy in all prosodic positions, (2) the breathy high-falling tone has a prosodically-variable f0, (3) the creaky low-falling tone has a prosodically-stable f0. The creaky low-falling tone is creakier than the modal low tone in all positions. Therefore, listeners may ignore f0 in the identification of the breathy high-falling tone because its pitch is prosodically variable. However, the creaky low-falling tone is consistently low-falling, which could explain why listeners rely on f0 as the dominant cue. Discussion will include why listeners ignore creaky voice if it is robust in production.
Phonetic variability of nasals and voiced stops in Japanese
Authors: Mukai Yoichi , Tucker Benjamin V.
Published: April 2018

We investigated the phonetic variability of nasals and voiced stops in a large-scale Japanese speech corpus. We then analyzed the types of variation across speech styles. In particular, we examined the instances where target segments are deleted or realized as different phonemes. We identified 285 lexical entries displaying variability of target segments in the Corpus of Spontaneous Japanese (Maekawa, 2003). In line with the findings of Arai (1999), we observed a few variants of voiced stops, such as /d/ becoming [n] in /doɴna/ “what” and /g/ being deleted in /daigaku/ “university.” We also found /b/ turning into [m], such as /boku wa/ “I am” becoming [mo kaː]. For nasals, we observed /zeɴiɴ/ “all the people” and /geɴiɴ/ “reason” becoming [zẽːɪɴ] and [gẽːɪɴ], in which the first /ɴ/ was deleted and the preceding /e/ was nasalized and lengthened. Our findings suggest that the extent to which speakers produce phonetic variants of target segments is likely specified lexically more than stylistically because we find instances of [zẽːɪɴ] and [gẽːɪɴ] produced across multiple speech styles. Further, we find more than 90% of the instances of /geɴiɴ/ were pronounced as [gẽːɪɴ] and 80% of /zeɴiɴ/ were pronounced as [zẽːɪɴ].
The effect of lexical competition on vowel duration before voiced and voiceless English stops
Authors: Glewwe Eleanor
Published: April 2018

One source of phonetic variation is lexical competition, which has been shown to cause both hyperarticulation, especially of vowel formants (e.g., Wright 2004), and reduction, manifested as shorter segment and word durations (Kilanski 2009, Gahl et al. 2012). Studies have found that lexical competition (e.g., having a minimal pair competitor, having more phonological neighbors) causes contrastive hyperarticulation of the initial stop voicing contrast in English: greater competition makes VOT longer for voiceless stops and/or shorter for voiced stops (Baese-Berk & Goldrick 2009, Nelson & Wedel 2017). I conducted a corpus study that looked for contrastive hyperarticulation of the final stop voicing contrast in English. The cue examined was preceding vowel duration. I did not find contrastive hyperarticulation: neither minimal pair competitor existence nor higher neighborhood density caused vowels to be longer before final [d] or shorter before final [t]. Instead, both competition metrics correlated with shorter vowel durations before [t] and [d]. This result is consistent with Goldrick et al. (2013)’s failure to find contrastive hyperarticulation of the final stop voicing contrast and their hypothesis that competition affects initial and final contrasts differently. It is also consistent with Gahl et al’s (2012) finding that high neighborhood density causes reduction.
The effect of domain-initial strengthening on voice onset time and vowel length on English oronyms
Authors: Evans Marisha D.
Published: April 2018

Oronyms are sets of words and phrases that contain the same phonemes but differ in word boundary (atop, a top). Past research established that domain-initial strengthening (DIS) affects segments at the beginning of prosodic domains. This research examines voice onset time and vowel length in English oronyms with the hope of finding a systematic strengthening of the target sounds word-initially. The word list consists of oronym pairs with the same phonemes and the same [vowel, voiceless stop, vowel] at the beginning of the oronym (e.g. atop/a top, attack/a tack). To elicit more natural-sounding tokens, participants created sentences with the target oronym at the beginning, or read already-prepared sentences. It is hypothesized that there will be a systematic strengthening of the initial segments (in the form of either a longer VOT or vowel length). This could mean speakers are fully aware of word boundaries and use DIS to help avoid lexical ambiguity when speaking.
The effect of cognitive load on the vowel onsets of older and younger adults
Authors: Morris Richard J. , MacPherson Megan K. , Roa Maria
Published: April 2018

The purpose of the study was to determine the effect of cognitive load on the vowel timing of older and younger adults. It was hypothesized that the participants would have longer and less extensive second formant (F2) transitions in the heavier cognitive load condition. It was also hypothesized that the older adults would have longer and less extensive F2 transitions than the younger adults. Eight adults, four younger and four older, equally matched for sex participated. They completed a sentence-level Stroop task in two conditions, congruent and incongruent, that varied on cognitive load. Eight sentences were produced in each condition. Plosive-vowel syllables were selected for measurement before the color words, at the color words, and after the color words. All participants exhibited longer and more extensive vowel transitions before and at the color word in comparison to afterwards. In the incongruent condition, the color words had longer F2 transition durations. The older adults had longer F2 transition durations than the younger adults. The F2 transition frequency extent was greatest at the color word. The older adults had wider F2 transitions at the color word that also were wider for the incongruent words.
Imitation of prosodic contours in word shadowing
Authors: Clopper Cynthia G.
Published: April 2018

In a word shadowing task, participants are asked to repeat auditorily-presented words aloud, providing a speech “shadow” to the stimulus materials. Previous research has demonstrated that even in this kind of non-interactive, non-social task, participants’ speech is more similar to the stimulus materials during shadowing than during a baseline reading task. These results are taken as evidence for implicit phonetic imitation during word shadowing. The current study examined imitation of prosodic contours in a word shadowing task. Participants were asked to first read a set of words aloud to establish their baseline production and then to repeat the same set of words after hearing them produced by a young female native speaker of Midwestern American English. This model talkers’ word productions all involved a non-falling intonation contour (i.e., either a plateau or a rise), consistent with “list intonation” in reading. Although the participants produced more than 50% non-falling contours in their baseline productions, they produced significantly more non-falling contours in the shadowing task, suggesting imitation of the prosodic contours produced by the model talker. The results of an acoustic analysis of the prosodic contours to examine the phonetic detail of the imitation will also be discussed.
Individual strategies in adaptation to altered auditory feedback
Authors: Bakst Sarah , Houde John F. , Lin Susan , Johnson Keith
Published: April 2018

Speakers monitor themselves while talking. When they hear a real-time altered version of their speech, they will change their articulation so that when they hear their altered speech, it matches their acoustic target [Houde and Jordan (1998, Science 20;279(5354):1213–1216)]. The experiment presented here used the novel addition of ultrasound imaging to reveal how speakers (n = 30) change their articulations in response to two different formant perturbations: raising of F1 in “head” and F2 in “hood.” Principal components analysis was used to identify speakers' individual strategies during adaptation. Some speakers use a single strategy for an entire adaptation block, while others change strategy. Speakers are also known to change production in a formant that was not altered [Katseff et al. (2010, JASA 127(3), 1955)]. The ultrasound analysis shows that at least for some speakers, change in two formants is linked to independent and uncorrelated articulatory components and possibly serves a perceptual purpose in compensation, rather than being an unintended result of the compensatory response. Preliminary results (n = 4) of adaptation to raising F3 in “heard” will also be presented. Modeling with the Maeda and Manzara synthesizers [Bakst and Johnson (2016, JASA 140(4), 3223)] correctly predicted speakers' articulatory strategies.
Acoustic cues to linguistic profiling? Machine learning of phonetic features of African American English
Authors: Arjmandi Meisam K. , Dilley Laura , Wagner Suzanne
Published: April 2018

Listeners can readily differentiate words spoken in an African American English (AAE) dialect from a Standard American English (SAE) dialect, even in absence of distinctive morphosyntactic features. However, it is still unclear what acoustic-phonetic cues listeners utilize to rapidly distinguish AAE from SAE. This study investigates the informativeness of various acoustic-phonetic cues to the characterization of AAE dialect. V and VC sequences (with C = /n/, /m/, /l/, /r/) from speech of 7 female speakers (4 SAE and 3 AAE), recorded during sociolinguistic interviews, were randomly selected and acoustically analyzed, controlling for coarticulatory context. Acoustic cues of F1, F2, F3, F4 formant trajectories, formant bandwidth, pitch variation, duration, intensity, and voice quality measures (e.g., harmonic-to-noise ratio, jitter, shimmer, and spectral slope) were measured in these segments to identify the extent of their contribution to separating AAE and SAE. The results from machine learning modeling of acoustic cues demonstrate that speech within an AAE dialect entails distinct acoustic characteristics and voice quality compared to SAE speech. These separate acoustic patterns between AAE and SAE dialect indicate the need for including dialect-specific acoustic cues both in automatic speech recognition applications and clinical assessments of speech-language disorders.
Understanding the speech cues to bisexuals
Authors: Yoshovska Mariya
Published: April 2018

The vast majority of research on speech patterns in the queer community has focused on gay and lesbian speakers. This study aims to expand our knowledge of speech in the queer community by focusing on the speech cues of adult bisexual speakers. For this study, adult lesbian, gay, bisexual, and straight cisgender American English speakers recorded the “Fire passage,” the “Rainbow passage,” and a description of their hometown. Vocal characteristics, such as duration, pitch, voice quality, formants, and speech rate, were measured to observe the differences between speech patterns of adult bisexual speakers and other queer and straight identities. The results suggest that bisexual and lesbian female speakers have naturally lower average pitch while straight speakers go up in pitch. Bisexual speakers maintain their pitch range between natural and read speech, while lesbian speakers have a wider pitch range during natural speech and straight speakers during read speech. The speech rate of bisexual and straight speakers decreases in natural speech, while it increases for lesbian speakers. Sentence-final phonation results were not conclusive between speaker identities. It is hypothesized that bisexual speakers produce less fronted /u/ and /ɑ/, higher /ɛ/ (low F1) and a more back /o/ (low F2).
On the use of decision feedback equalization for continuous active sonar
Authors: Pelekanakis Konstantinos , Bates Jeffrey R. , Tesei Alessandra
Published: April 2018

Continuous Active SONAR (CAS) systems allow duty cycles up to 100% and so lower target association errors are possible as compared to Pulse Active Sonar (PAS). Large time-bandwidth product Linear Frequency Modulated (LFM) signals are the de facto standard for this type of SONAR systems, yet, these signals suffer from low processing gains when the ocean exhibits low-spatio temporal coherence. In this work, we depart from the typical sub-band matched filter processing and propose to adopt signal processing techniques used in underwater acoustic communications. In particular, we analyze Binary Phase Shift Keying (BPSK) signals via an adaptive Decision-Feedback Equaliser (DFE). The DFE is able to adapt to environmental changes based on the known transmitted bits. The operational bandwidth is 1500–4000 Hz and the BPSK signals are transmitted in two non-overlapping bands to avoid transmit interference during reception. The performance of the proposed system is demonstrated based on field data recorded during a sea experiment off the Coast of La Spezia in October 2017. The key result here is that the Doppler measurement update rate of the echoes is as fast as the bit rate of the transmitted BPSK signal.
Parametric bandwidth synthesis for active sonar
Authors: Soli Jonathan B. , Krolik Jeffrey
Published: April 2018

This talk presents an unconventional range processing technique applicable to linear FM pulsed and continuous active sonar. Parametric bandwidth synthesis (BWS) involves performing linear-predictive extrapolation using a low-order parametric autoregressive (AR) model to extend the bandwidth of received sonar returns. Synthetically increasing the bandwidth of echoes results in improved range resolution and greater pulse compression gain compared to standard matched filtering. It should be noted that despite the resolution improvement, BWS does not improve ranging accuracy beyond that of the transmitted signal. Using a low-order AR model for BWS enhances specular target returns and discrete scatterers, while not enhancing diffuse multipath, reverberation, and noise returns. BWS performance was verified in simulation and with sea trial data from the Littoral Continuous Active Sonar 2015 (LCAS-15) experiment. Processed results confirm that BWS improves range resolution of the echo repeater target, while suppressing multipath, diffuse reverberation, and noise. Analysis of the practical limits of BWS are also included.
Modeling acoustic wave propagation and reverberation in an ice covered environment using finite element analysis
Authors: Simon Blake , Isakson Marcia J.
Published: April 2018

A three-dimensional, longitudinally invariant finite element model of acoustic propagation and reverberation in an ice-covered shallow water waveguide has been developed. The ice is modeled as both an elastic medium and a pressure release surface. Transmission loss levels are calculated and compared for both assumptions of ice. Using Fourier synthesis, the time-harmonic acoustic pressure results are transformed into the time domain, and reverberation levels are then compared for both models. Finally, using a fully three-dimensional version of the finite element model, compressional-to-shear wave conversion at the elastic ice and water interface is characterized to inform propagation mechanisms of acoustic waves in Arctic ice sheets. [Work supported by ONR, Ocean Acoustics and the Robert W. Young Award for Undergraduate Student Research in Acoustics.]
Nonequilibrium optical control of dynamical states in superconducting nanowire circuits
Authors: Madan Ivan , Buh Jože , Baranov Vladimir V. , Kabanov Viktor V. , Mrzel Aleš , Mihailovic Dragan
Published: April 2018

First observation of the photoinduced transition between dynamical superconducting states and hidden dynamical states.