bluuebunny/crossref_metadata_2025 huggingface dataset:
Rhythm segment constitution showing regular periodicity
Authors: Nakamura Shizuka
Published: November 2016

To verify the possibility of regular periodicity of English rhythm, each sentence was divided into respective rhythm segments and the properties of its durations were analyzed. Rhythm segment (RhySeg) was defined as a segment including one syllable with a primary/secondary stress to which an adjacent unstressed syllable(s). The following locations of a stressed syllable in RhySeg were compared: forward, semi-forward, middle, semi-back, and back. To reflect the perceptual effect to the RhySeg constitution, the following factors to equally compress all of the unstressed syllables were compared: 0.1-1.0 at an interval of 0.1. To find the RhySeg constitution showing regular periodicity, not only the degree of concentration of the distribution, but the degree of closeness between RhySeg with a secondary stress and 1/2 of that with a primary stress, whose engagement on regular periodicity was indicated in previous studies, was applied as a criterion. Comparative experiments showed the best when the stressed syllable located semi-forward or forward, and the factor was 0.7. Furthermore, the result of harmonic analysis and resynthesis applied to the time function of the average duration of syllables in a sentence indicated periodicity is consisted of the combination of the fundamental and its second harmonic components.
Laryngeal dynamics and vocal fold tissue engineering in a rabbit model
Authors: Döllinger Michael , Birk Veronika , Kniesburges Stefan , Alexiou Christoph , Wendler Olaf , Pöttler Marina , Schützenberger Anne , Dürr Stefan
Published: November 2016

Vocal fold surgery, especially due to cancer treatment, yields reduced voice quality and consequently reduced quality of life for patients. Hence, the development of vocal fold implants, to restore missing vocal fold tissue after surgery, is an urgent clinical need. To achieve this, a rabbit model is applied as a first step. Ex-vivo dynamic experiments were performed on twelve rabbit larynges providing normative phonatory data. The larynges were phonated at sustained phonation for different elongation levels at varying subglottal pressures. Laryngeal vibrations, airflow, and acoustics were recorded. Subsequently, for each larynx, a defined area of one vocal fold was resected, simulating the surgical intervention, and were phonated again with the same stimulations. The untreated larynges showed expected behavior regarding flow-pressure relation, acoustics and dynamics. In contrast, the phonatory quality of the resected larynges was significantly reduced showing, as expected, highly disturbed dynamics and acoustics. Parallel, vocal fold fibroblasts were isolated from rabbit larynges and cultured. These cells were treated with superparamagnetic iron oxide nanoparticles enabling their magnetic control. By magnetic tissue engineering three dimensional structures were designed. Next, the applicability of this tissue engineered implant will be tested in the dynamic ex-vivo rabbit model to compare the phonatory outcome.
A study on prediction of end-of-utterance by prosodic features and phrase-dependency structure in spontaneous speech
Authors: Ishimoto Yuichi , Teraoka Takehiro , Enomoto Mika
Published: November 2016

This study is aimed at predicting the end of utterance by prosodic features and syntactic structure for spontaneous speech. In spontaneous everyday conversation, participants must predict the ends of utterances of a speaker to perform smooth turn-taking. We consider that they utilize not only syntactic factors but also prosodic factors for the end-of-utterance prediction because of the difficulty of prediction of a syntactic completion point in spontaneous Japanese speech. In previous studies, it was observed that prosodic factors changed such that the general fundamental frequency of utterance declined gradually toward the end of an utterance, and the intensity decreased significantly in the final accentual phrase. However, it is not clear what prosodic features support the prediction. We focused on dependency structure among bunsetsu-phrases as the syntactic factor and investigated the relation between the phrase-dependency and prosodic features based on a spontaneous Japanese conversation corpus. The results showed that the average fundamental frequency and the average intensity for accentual phrases did not decline until the modified phrase appeared. This suggests the possibility that prosodic changes and phrase-dependency relations inform the hearer that the utterance is approaching its end.
Mandarin tone recognition based on unsupervised feature learning from spectrograms
Authors: Chen Charles , Bunescu Razvan , Xu Li , Liu Chang
Published: November 2016

In tone languages, such as Mandarin Chinese, a syllable with different tones conveys different meanings. Previously, Mandarin tone recognition based on Mel-frequency cepstral coefficients (MFCCs) and Convolutional Neural Networks (CNN) was examined and the results outperformed the model of conventional neural network using manually edited F0 data. In the present study, Mandarin tone recognition based on spectrograms, instead of MFCCs, was explored. Unsupervised feature learning was applied to the unlabeled spectrograms directly with a denoising autoencoder (dAE). Then, the model convolved the labeled spectrograms with the learnt “sound features” and produced a set of feature maps. A dataset that consisted of 4500 monosyllabic words collected from 125 children was used to evaluate the recognition performance. Compared with methods based on MFCCs, there are more parameters to train in the new approach based on spectrograms. As a result, the new model might better capture the statistical distribution in the original data. Therefore, the new approach, with unsupervised feature learning, could perform even better than previous methods based on MFCCs or those based on the extracted F0 information. The advantages and shortcomings of various approaches for lexical tone recognition will be discussed. [Work supported in part by the NIH NIDCD Grant No. R15-DC014587.]
A computational study of vocal fold dehydration during phonation
Authors: Wu Liang , Zhang Zhaoyan
Published: November 2016

Vocal fold dehydration during phonation is investigated in a continuum model of the vocal folds. Based on the linear poroelastic theory, the model simulates water movement inside the vocal folds during phonation, water exchange between the vocal folds and the surface mucosal layer through the epithelium layer, surface water accumulation and loss to the glottal airway, and water resupply from blood through the lateral boundary. Parametric studies are conducted to investigate water loss within the vocal folds after 5 minutes of phonation at different voice conditions. The results show that with normal water resupply from the blood, water loss within the vocal folds increases with greater vibration amplitude and higher epithelium permeability. At very large vibration amplitudes, the water loss within the vocal folds can be as high as 3%, which may severely affect body functions and possibly phonation characteristics and vocal effort. Reduced water resupply from blood further increases the degree of dehydration. In contrast, water loss in the surface mucosal layer is an order of magnitude higher than water loss within the vocal folds, indicating the surface dehydration level is likely not a good indicator of the degree of dehydration within the vocal folds.
Empirical relationship in excised canine larynx
Authors: Khosla Sid M. , Oren Liran , gutrmark ephraim
Published: November 2016

Our lab uses particle imaging velocimetry to measure intraglottal pressure and geometry. Although we have described relationships between maximum divergence angle (MDA) and maximum negative pressure during closin (MNP) for individual experiments, we have not yet looked at the combined data for over 15 larynges without a vocal tract. In this presentation, plots will be shown for the following relationships: MDA vs MNP, MNP vs vortex strength, MNP vs maximum closing speed and maximum vocal fold closing speed vertical stiffness gradient vs divergent angle. Correlation coefficients and generalized empirical relationships will be shown. This will allow approximations for finding variable that are hard to calculate computationally. For example, it is much easier to calculate divergence angle than vortex strength. Comparison of empirical and computational relationships will be described.
Two types of intermediate phrase boundary tones in Korean
Authors: Ahn Hyunah
Published: November 2016

The current study shows that there are two types of Intermediate Phrase (ip) boundary tones, distinctively used for focus marking and syntactic phrasing in spoken Korean. Jun (2011) argued that focused ip (ipF) are characterized by raised initial high ( + H) tone and dephrasing of subsequent materials and syntactic ip(ipS) by a phrasal juncture (larger than AP but small than IP) on the phrase-final boundary and partial dephrasing of the following phrase. To empirically test the claim, an experiment was conducted where participants were given an ambiguous sentence to compose a story with. The ambiguous construction was made up of an overt NP, a VP and a covert NP. The ambiguity depended on where the covert NP goes. If the word order is a. “overt NP + covert NP + VP,” the syntactic juncture between the overt NP and the VP is larger than when the covert NP is placed before the overt NP (b. covert NP + overt NP + VP). In stories where the syntax of the sentence was a, the likelihood of ipS was significantly larger than when the syntax was b (p <.05). The distribution of ipF was related to the information structure of the story (operationalized as the location of the sentence within the story) (p <.01). The results show that the two different types of intermediate phrase (ip) boundary tones are used in real-time production of spoken Korean. The findings provide empirical evidence for Jun's (2011) claim for the Korean prosodic hierarchy.
Aeroacoustic sound generation during phonation in a synthetic larynx model
Authors: Kniesburges Stefan , Lodermeyer Alexander , Tautz Matthias , Becker Stefan , Döllinger Michael
Published: November 2016

The fluid flow within the human larynx plays an essential role in the fluid-structure-acoustic interaction during voice production. This study addresses the supraglottal flow field downstream of aerodynamically driven, synthetic vocal folds based on the M5 model. The larynx replica is designed to provide full optical access to the flow region. Two different approaches based on Particle-Image-Velocimetry (PIV) were applied for measuring the flow: Phase-averaged (PA) and High-speed (HS) PIV. Beside a comparison of the supraglottal flow field, the acoustic sources were calculated based on both PIV approaches. Furthermore, the simulated far-field sound based on the HS-PIV data is compared to experimental results. Within both PIV approaches, the typical asymmetric jet flow was detected. However, transient flow field characteristics as high vorticity and maximal velocities peaks could only be observed in HS-PIV data. A strong aeroacoustic source was found immediately downstream of the glottis for both PIV approaches. However, the sources in the jet region could only be observed in the HS-PIV data owing to the averaging procedure for PA-PIV. The comparison between simulated and measured sound spectra revealed good agreement. In contrast, subharmonic tones could not be detected hinting to an additional non-aeroacoustic mechanism of sound generation.
Psychometric measurement of vocal strain using a matching task with sustained vowel stimuli
Authors: Eddins David A. , Skowronski Mark D. , Anand Supraja , Shrivastav Rahul
Published: November 2016

Psychometric measurement of voice quality is important for quantitative assessment of dysphonia. Previous work established the efficacy of a single-variable matching task to index vocal breathiness and roughness using appropriately designed comparison stimuli, providing a context-independent perceptual task that improves the validity and accuracy of perceptual data compared to magnitude estimation or rating tasks. Physiologically, vocal strain is characterized by excessive vocal fold adduction during phonation, resulting in a glottal pulse with a low duty cycle. The narrowing of the glottal pulse causes the excitation spectrum roll-off to decrease, resulting in a flattening of the spectrum and significant changes in spectral skewness and kurtosis [Moore et al., 1997]. Analogous to comparison stimuli for breathy and rough measurement, a set of noisy sawtooth waveforms was created using modified step filters that varied in spectral slope 1 dB/octave steps, producing a wide range of perceived strain in the comparison stimuli. The comparison stimuli were used in a listening experiment to measure the perceived strain of a set of 15 samples of /a/ selected from the Kay-PENTAX Disordered Voice Database using stratified sampling. The results validate the strain comparison stimuli and extend the matching task paradigm to the three primary dimensions of voice quality perception.
Perception and analysis of “Moe “voice
Authors: Takano Sayoko , Yamada Masashi
Published: November 2016

The term “Moe” is used in Japanese animation and cartoons. “Moe” mainly refers to cute young girls, but it does include direct sexual desire. We investigated the “Moe” voice using “onichan CD” which includes 1200 different utterance from 12 voice actress. “Onichan” means brother in Japanese, and the voice actress says the word with happiness, anger, sadness, adding up to 100 different situations. In experiment one, the impressions of the “Moe” voice was examined using Semantic Differential Method. The subjects answer revealed that Moe is not related to the emotions such as happiness or sadness, but “Moe” is comfort to the listener. Furthermore, “Moe” is mostly associated with the voice actress. This indicates that “Moe” voice is mainly related to the personality. In experiment two, the speech voice was analyzed to measure the acoustic characters. In experiment three, the voice was resynthesized using TANDEM-STRAIGHT. All the results showed that the “Moe” voice is associated with the young girl as small, energetic hypertension.
Japanese “street seller’s voice”
Authors: Sadanobu Toshiyuki , Zhu Chunyue , Erickson Donna , Obert Kerrie
Published: November 2016

The term “Street Seller’s Voice” (henceforth SSV) refers to a category of voice quality which can be uttered only by, but not all, Japanese young girls, especially selling something cute and fashionable. We can hear this voice at cake shops, but never at “wagashi” (i.e., Japanese cake) shops, since “wagashi” is not cute and fashionable, unlike western cake which for Japanese people is cute. In order to catch the nature of SSV we recorded voices of several street sellers, and also conducted MRI experiments with 3 subjects. The results suggest that SSV has a twang quality [e.g., Estill et al. 1983, Proc. Stockholm Music Acoustics Conference, 157-174; Honda et al. 1995, Vocal Fold Physiology; Voice Quality Control, 23-38], which is manifested in the acoustic signal by, among other things, sustained high energy in the upper frequency regions, and may possibly be produced with high larynx and change in pharyngeal cavity size. One advantage to this type of voice production is it is easily heard in a noisy environment and puts minimum strain on the vocal folds [Estill, personal communication]. [This work was supported by the following grants: JSPS Grants A #15H02605 and A #25240026.]
A study on judgement of intoxication using pitch alteration of speech signal in VHF environment
Authors: Lee Won-Hee , Bae Myung-Jin
Published: November 2016

In this study, speech characteristics from before and after alcohol intoxication has been comparatively analyzed though speech analysis to obtain the degree of intoxication along with its parameters in VHF environment. It is studying speech characteristics of alcohol intoxicated person as pitch and formant and changing of sound levels, but it cannot analyze about before and after alcohol intoxication using these speech characteristics because it is sensitive about environmental changing so we need finding more precise parameters. Especially, speech signal is distorted from the frequency carrier characteristics in VHF environment. Thus, we study speech characteristics from before and after alcohol intoxication using pitch alteration in VHF environment.
Perceived vocal attractiveness by gay listeners in Hong Kong
Authors: Leung Shue-sum , Xu Anqi
Published: November 2016

This study investigates how Cantonese-speaking homosexual males perceive vocal attractiveness; namely, how different phonetic properties of voice influence their judgment. To this end, the present project follows the methodology in Xu et al’s (2013) study of vocal attractiveness and emotion in English, and recruited 14 Cantonese-speaking gay men in Hong Kong to rate the attractiveness of digitally synthesised stimuli. The stimuli varied in voice quality (breathy / modal / pressed), fundamental frequency and formant dispersion, all of which were means to project the speaker’s intended body size. The attractiveness ratings show that homosexual male subjects prefer male voices with low pitch, breathy voice quality and normal (neither dense nor sparse) distribution of formants. Interestingly, these preferences resemble the ratings by female English subjects in Xu et al’s (2013) study with one exception—the females favoured male voices with densely distributed formants, which signal a large body. This divergence needs to be further investigated by follow-up studies targeting different language and sexuality groups, in order to distinguish factors that are universal and language-specific.
Importance of F0 for predicting vocal emotion categorization
Authors: Pichora-Fuller Margaret K. , Dupuis Kate , Van Lieshout Pascal
Published: November 2016

Affective prosody is used to produce and express specific emotions to conversation partners. While pitch has been identified as a crucial cue for differentiating between emotions, there has been significant variation in the stimuli used by different groups of researchers to examine the acoustic cues necessary for the perception of vocal emotions. The Toronto Emotional Speech Set consists of 2800 items: 200 sentences (carrier phrase “say the word” followed by a target word) spoken by two adult female actors (one younger and one older) to portray seven emotions (anger, disgust, fear, sadness, happiness, pleasant surprise, neutral). In the current study, these stimuli were analyzed to determine which acoustical cues accounted for the most variance in categorizing stimuli into one of the seven pre-determined emotional conditions. The acoustical characteristics of mean duration, mean intensity, mean F0, mean range of intensity, and mean range of F0 were analyzed using a customized Praat script for each of the 2800 stimuli. For both talkers, mean F0 was the most important acoustical cue for accurately categorizing the TESS stimuli into the different emotional conditions. The second most important cue was F0 range for the younger talker and duration for the older talker.
Sound quality improvement based on weighted AM/FM modulations for parametric loudspeaker
Authors: Ariyoshi Kirara , Kimura Takuya , Fukumori Takahiro , Nakayama Masato , Nishiura Takanobu
Published: November 2016

A parametric loudspeaker has high-directivity, and it utilizes a modulated wave that is designed by modulating an ultrasound wave with an audible sound wave. The conventional modulation methods, amplitude modulation (AM) and frequency modulation (FM), have been proposed. Furthermore, an AM/FM method has been proposed that can improve the sound pressure level (SPL). However, its sound quality is inferior to the AM method. The AM/FM method utilizes constant modulation parameters in all frequency bands. However, the power of audible sound demodulated by AM and FM modulations is different at each frequency band. Therefore, we propose a new AM/FM method that utilizes the weighted modulation parameters in each frequency band and can improve the sound quality. The proposed method has comparable sound quality to the AM method and a comparable SPL to the FM method. In this proposed method, we divided all frequency bands into three frequency bands and utilized the optimum weighted modulation parameters in the three frequency bands on the basis of the results of the preliminary experiments. As a result of evaluation experiments, we confirmed the effectiveness of the proposed method compared with the conventional methods.
The acoustical features analysis of Indo-Pacific humpback dolphins’ whistle and modeling research
Authors: Cang Siyuan , Sheng Xueli , Sun Jintao , Lu Dian , Yin Jingwei , Guo Longxiang
Published: November 2016

Depending on species-specific characteristics of echolocation and recognition,dolphin could travel in groups without collision, and they could also prey and defend mutually. As a multi-harmonics, frequency-modulated signal, the variety of whistles revealed the rich group identification and location information of free-ranging Indo-Pacific humpback dolphins (Sousa chinensis). This paper introduces the features of whistle on the basis of Joint time-frequency distribution, dealing with recording data collected in the area of Guangxi and Zhanjiang seacoast, in China. Then the ability of individual identification is discussed from the correlation of whistles, we will get the knowledge of dolphins how to cognize the communication information in the complex environment. The transmission loss function will be depicted using the BELLHOP at last. By extracting the acoustical features, the modeling of whistle signal is implemented based on the Sinusoids Model (Buck, 2000). Specifically, the validity of mathematical model is proved according to comparison with the recording data.
Application of scanning acoustic and photoacoustic microscopes in orthopedic surgery
Authors: Hagiwara Yoshihiro , Sajo Yoshifumi
Published: November 2016

Demands for orthopedic surgery, decreasing pain and disabilities, is increasing in developed countries with older nations. Together with increasing number of patients, its cost is now rising. Among modalities for noninvasive diagnosing techniques, such as plain X-rays, computed tomography, magnetic resonance imaging (MRI) and ultrasonography (US), MRI is a powerful tool for evaluating anatomical abnormalities. However, location and economic limitations for routine use remain. US is quick and inexpensive with a higher resolution than MRI. US plays an important role in assessing musculoskeletal soft tissues. A scanning acoustic microscope (SAM) characterizes biological tissues by estimating the elastic parameters based on sound speed. Biomedical photoacoustic (PA) imaging has the unique capability of combining high optical contrast and high ultrasound resolution in a single modality. Osteoarthritis and frozen shoulder are the major problems in musculoskeletal diseases. Osteoarthritis is a degenerative joint disorder characterized by the progressive degeneration of articular cartilage, osteophyte formation, and subsequent joint space narrowing. Further, frozen shoulder is characterized with severe pain and a decrease in shoulder motion, which is caused by joint capsular stiffness. We applied SAM and PA to animal models for assessing osteoarthritis and human samples with frozen shoulder.
Convolutional bidirectional long short-term memory hidden Markov model hybrid system for polyphonic sound event detection
Authors: Hayashi Tomoki , Watanabe Shinji , Toda Tomoki , Tori Takaaki , Roux Jonathan L. , Takeda Kazuya
Published: November 2016

In this study, we propose a polyphonic sound event detection method based on a hybrid system of Convolutional Bidirectional Long Short-Term Memory Recurrent Neural Network and Hidden Markov Model (CBLSTM-HMM). Inspired by the state-of-the-art approach to integrating neural networks to HMM in speech recognition, the proposed method develops the hybrid system using CBLSTM to estimate the HMM state output probability, making it possible to model sequential data while handling its duration change. The proposed hybrid system is capable of detecting a segment of each sound event without post-processing, such as a smoothing process of detection results over multiple frames, usually required in the frame-wise detection methods. Moreover, we can easily apply it to a multi-label classification problem to achieve polyphonic sound event detection. We conduct experimental evaluations using the DCASE2016 task two dataset to compare the performance of the proposed method to that of the conventional methods, such as non-negative matrix factorization (NMF) and standard BLSTM-RNN, and also investigate the effect of network structures on the detection performance.
Chatter diagnosis using Mel frequency cepstral coefficient of vibrational signal for various operating conditions
Authors: Jeong KwangHun , Lee JeWon , Park Junhong
Published: November 2016

The chatter reduces quality of the machined parts and induces vibration and sound that is different from those under normal cutting process. A variety of cutting conditions are significantly correlated with the occurrence of chatter. After changing of the cutting conditions such as rotational speeds and depths of machine tools blade, the vibration signals was measured using vibrational accelerometers. The chatter diagnosis algorithm using Mel Frequency Cepstral Coefficient (MFCC) and Deep belief network (DBN), one of the Deep learning algorithm is proposed. Deep belief network is effective on classifying complicated signals as it represents the hierarchical cognitive process of a human brain. To acquire features from the distinctive noise and vibration under normal and chatter status, the MFCCs was used. Chatter diagnosis algorithm, DBN using MFCCs as input features, is suggested and verified.
Bottom-diffracted surface-reflected arrivals in the North Pacific
Authors: Stephen Ralph A. , Worcester Peter F. , Bolmer S. T. , Udovydchenkov Ilya A. , Dzieciuch Matthew A.
Published: November 2016

Bottom-diffracted surface-reflected (BDSR) arrivals were first identified in the 2004 Long-range Ocean Acoustic Propagation Experiment (LOAPEX) in the North Pacific (Stephen et al., 2013, JASA, 134, 3307-3317). In deep water, ambient noise and PE predicted arrivals are sufficiently quiet that BDSR arrivals, scattered from small seamounts, can be the largest amplitude arrivals observed. The Ocean Bottom Seismometer Augmentation in the North Pacific (OBSANP) Experiment in June-July 2013 studied BDSRs at the same site in detail. They are most readily identified by their move-out on lines of transmissions and are clearest on the vertical component channel. There appear to be two classes of diffractors. The diffraction point for Type 1 BDSRs occurs on the side of small seamounts and is substantially out of the source-receiver sagittal plane (for example, the BDSR observed on NPAL04). The diffraction point for Type 2 BDSRs is essentially in the source-receiver sagittal plane and occurs on the relatively featureless abyssal plain. In at least one case the same BDSR is observed for 77.5, 155 and 310 Hz M-sequence transmissions. Other characteristics of BDSRs will be discussed. [Work supported by ONR.]
Acoustic features of sharp and continuous three-dimensional curved coastal fronts
Authors: DeCourcy Brendan J. , Lin Ying-Tsong , Siegmann William L.
Published: November 2016

Three-dimensional curved shelf-slope fronts have been modeled with sharp [Lin and Lynch, J. Acoust. Soc. Am. (2012)] and continuous [DeCourcy et al., J. Acoust. Soc. Am. (2016)] sound speed changes. For the sharp front, expressions were found for determining dependence of acoustic quantities such as modal speeds on feature-model parameters. Asymptotic approximations are used to simplify terms in the dispersion relation for the horizontal wavenumber, and further analysis leads to convenient and accurate formulas for the parameter dependence. Corresponding results will be presented for the continuous front, which possesses a different class of acoustic modes known as tunneling modes that carry larger amounts of energy across and along the front than other modes. Results for both frontal models will be discussed, comparing and contrasting characteristics including wavenumber distributions, mode types, and parameter dependences. An important goal is to examine the similarities and differences for sharp or continuous fronts in the sensitivity of acoustic quantities to feature parameters, such as front location and width, bottom slope angle, and source frequency. This would permit identification of situations where the more convenient sharp front model is appropriate. [Work supported by ONR Grants N00014-14-1-0372 and N00014-11-1-0701.]
Arctic ambient noise measurement comparisons in the Beaufort Sea
Authors: Poulsen Andrew , Schmidt Henrik
Published: November 2016

During ICEX 2016, an MIT autonomous underwater vehicle (AUV) was deployed in the Beaufort Sea region of the Arctic Ocean with the technical objectives of demonstrating the deployment, operation and recovery of an AUV with a towed array under extreme under-ice Arctic conditions, and the scientific objective of characterizing the acoustic environment. Part of this effort included suspending the AUV from a hydro-hole with the acoustic array hanging in a vertical configuration. This new data set created a choice opportunity to reprocess similar vertical array data from the same region of the Beaufort Sea collected by MIT during SIMI 1994. In the intervening twenty-two years between these two ice camps, significant changes have occurred in the Arctic, including rapidly reducing extent and thickness of the summer ice cover. Furthermore, a persistent inflow of a shallow “tongue” of warm Pacific water has recently been discovered in the Beaufort Sea, creating a strong acoustic duct between approximately 100 and 200 m depth. This paper presents noise properties measured more than two decades apart in a region of rapid and significant change. [Work supported by ONR and DARPA.]
Environmentally adaptive autonomy for acoustic communication and navigation in the new Arctic
Authors: Schmidt Henrik , Schneider Toby
Published: November 2016

The particular sensitivity of the Arctic to climate change is well established. and the significance to undersea operations can be dramatic. As part of the recent ICEX16 US Navy Exercise in the Beaufort Sea, MIT deployed an autonomous underwater vehicle with a towed hydrophone array below the ice cover for assessing the climate induced changes to the undersea ambient noise environment. The safe underwater operation depended on navigation updates from the submarine tracking range being communicated to the vehicle for fusion with the onboard inertial navigation. However, the changes in the environment severely deteriorated the tracking performance compared to previous deployments. The reason was clearly associated with a previously observed neutrally buoyant layer of warm Pacific water persistently spreading throughout the Beaufort Sea, which severely alters the acoustic environment with dramatic effects for both long and short range acoustic sensing, communication and navigation. This paper describes the effects observed and discusses how robust acoustic connectivity in this environment makes it paramount that the manned or unmanned undersea platforms are capable of adapting to the environment for sensing, communication, and navigation. [Work supported by the Office of Naval Research.]
The design and implementation of ocean ambient noise acquisition system based on the underwater glider
Authors: Liu Lu
Published: November 2016

Ocean ambient noise (OAN) is the background noise of the ocean,which is considered as the interference for the underwater acoustic equipment,on the other hand,it can be used to invert the parameters of the ocean environment. It is important to acquire and study the spatial temporal characteristics of ocean ambient noise. As a new type of underwater detection platform,underwater glider's performance is suitable to acquire the ocean ambient noise. This paper designed and realized an OAN acquisition system (OANAS),which is mounted on the Underwater glider. The system mainly includes two parts,the deepwater hydrophone array and the acquisition system. This design uses the ADI's BF518,the AD73360 and the uClinux to make the acquisition system have high speed,low power consumption and low noise abilities,it can also sample eighteen underwater signal roads synchronously and meet the requirement of the system. The data memorized is proved effective,the system is proved to be stable and meet the design requirement through the test which the OANAS mounted on the Hybrid Underwater Glider in the National Ocean Technology Center.
Eigenvalues of the sample covariance matrix for a vertical array in shallow water
Authors: Li Jie , Gerstoft Peter
Published: November 2016

The eigenvalue spectrum of the sample covariance matrix (SCM) contains valuable information about the environment and the source and noise generation. Random Matrix Theory (RMT) combined with physical models is used to explain the eigenvalue distribution. For conventional three-dimensional and two-dimensional free space isotropic noise models, there is a jump in the eigenvalue spectrum of SCM which only depends on array properties (element spacing to wavelength ratio). This paper investigates the eigenvalue distribution of SCM for a vertical array in shallow water noise environment using Harrison’s noise model [Harrison, J. Acoust. Soc. Am. 99, 2055-2066 (1996)]. Results show that when bottom is considered, the jump location depends on both array and bottom properties. RMT is applied to study the eigenvalue spectrum estimation with different sound speed and attenuation in the bottom. Shallow water vertical array data are analyzed and it is demonstrated that the eigenvalues of the SCM compare well with theory.
Acoustic data quality assessment tools and findings for ocean observing systems
Authors: Dakin Thomas , Dorocicz John , Biffard Ben , Merchant Nathan D. , Hannay David , Mihaly Steve , Jeffries Marlene , Bedard Jeannette
Published: November 2016

Ocean Networks Canada (ONC) operates long time series, ocean observatories in the Pacific and Arctic. These include the large VENUS and NEPTUNE observatories, many small community based observatories and the Underwater Listening Station (ULS) for the Vancouver Fraser Port Authority. Passive acoustic monitoring systems are a component of all ONC observatories and passive acoustic data quality is therefore a concern. All the observing systems have multiple underwater electronics and sensor types, many of which can negatively impact the passive acoustic sensor data. Hydrophone sensitivity degradation due to time, water absorption, and biofouling need to be assessed to ensure accurate ambient noise measurements and accurate vessel underwater radiated noise level measurements. The performance and suitability of the hydrophones for specific areas also needs to be assessed so the acoustic analysts can be aware of the hydrophone induced data limitations. ONC has been examining the use of in situ calibration verifications, spectral probability density (SPD) plots, spectrograms, and wave data as tools to assess the passive acoustic data quality. The preliminary findings on the impact of all of the above acoustic error sources are presented.
Optical detection of mach shock wave cones in water using refracto-vibrometry
Authors: Huber Matthew T. , Huber Nathan , Huber Thomas
Published: November 2016

Recently, a hydrophone array was used to demonstrate Mach shock wave cone formation in water when 1m diameter steel pile rods for civil structures were driven into the ground by massive impact hammers. These shock wavefronts are of concern for marine mammals and fish. In the current project, Mach shockwave cones were directly imaged using refracto-vibrometry. A Polytec PSV-400 laser Doppler vibrometer was directed through a water tank towards a stationary retroreflective surface. The density variations of acoustic wavefronts which pass through the laser cause variations in the optical path length between the laser and retroreflector. This results in a time-varying modulation of the laser signal returning to the vibrometer, enabling optical detection of the acoustic wavefronts. A 35 mm diameter rod (steel or other metal) immersed in a water tank was repeatedly “impacted” by narrow pulses from a 1 MHz ultrasound transducer. The vibrometer sampled numerous scan points to generate videos of the time evolution of a Mach cone wavefronts launched as the compressional and shear waves travel through the rod. The angle of the Mach cone produced is consistent with the speed of waves in the rod.
Statistical wavelet filtering for impulsive noise mitigation
Authors: Sarkar Jit , Verlinden Christopher M. , Tippmann Jeffery D. , Hodgkiss William S. , Kuperman William A.
Published: November 2016

Impulsive noise sources in acoustic data can represent a significant amount of contamination that is not easily addressed by spectral methods alone. In ocean acoustics, such noise sources can be biological in nature, e.g., marine mammal localization clicks, or even mechanical noise induced on an instrument itself. While the broadband character of an impulse does not lend itself to frequency domain filtering, the wavelet domain is more appropriate and has been used to analyze impulsive sources of interest in the past. We present a method for filtering unknown nuisance impulses using basic statistics of the continuous wavelet transform (CWT), with minimal disturbance to the remaining signal(s) of interest. Examples from both simulation and collected ocean acoustic data are presented.
Baleen whale calling behavior and response to anthropogenic sound
Authors: Stimpert Alison K. , DeRuiter Stacy L. , Falcone Erin A. , Joseph John , Margolina Tetyana , Moretti David , Fregosi Selene , Friedlaender Ari S. , Calambokidis John , Tyack Peter L. , Goldbogen Jeremy A. , Southall Brandon L.
Published: November 2016

Without a means of studying large whales in a controlled experimental environment, less is understood about their sound production mechanisms than is understood about those of smaller odontocetes. To describe call production behavior in fin whales, we used a recent technique that correlates fast-sampling accelerometer signals from tags with concurrently recorded acoustic signals to identify calls produced by the tagged animal. We tagged 18 fin whales as part of the Southern California Behavioral Response Study (SOCAL BRS), of which four were confirmed to be calling. We were then able to describe their kinematic and social behavior in relation to call production. Behaviors associated with elevated call rates included shallow maximum dive depths, little body movement, and negative pitch in body orientation, similar to some other calling baleen whale species. These are the first descriptions of body orientation and dive depths at which fin whales are most likely to call. We also describe calling responses (or lack thereof) from blue and fin whales exposed to simulated mid-frequency active sonar. The call behavior characterizations presented here will help with predicting calling behavior from surface behavior, informing interpretation of passive acoustic data, and further investigating effects of anthropogenic sound on baleen whales.
Vocal response of dugongs (Dugong dugon) to playbacks of conspecific calls suggest ranging function of chirps
Authors: Ichikawa Kotaro , Arai Nobuaki , Kittiwattanawong Kongkiat
Published: November 2016

Dugongs vocalize bird-like calls, such as chirps and trills but the functional definitions of the calls are yet to be clarified. A series of playback experiments was conducted in Thai waters to investigate their call-back behavior. The population was exposed to 4 different playback stimuli; a recorded wild dugong’s chirp, a synthesized down-sweep sound having similar frequencies to the dugong chirp, a synthesized constant-frequency sound, and no sound as a control. Vocalizing dugongs were localized using an array of stereo-underwater-recording systems (AUSOMS-Ds). Total of 4068 calls were observed in reaction to the stimuli. Wild dugongs vocalized more frequently after the playback of dugong chirps (2.8 calls/min) than those of constant-frequency (0.55 calls/min) and control (0.2 calls/min). Ratio of the dugong chirps to all of the call type increased during the playback period. Dugongs were localized on 52 occasions within 25 m range from the playback source. Source level and duration of the chirps from wild dugongs responding to the playback showed positive correlation with distances between the caller and the playback speaker. These results suggest that dugongs can advertise their relative locations by exchanging chirps. Frequency-modulated chirps may have facilitated ranging between individuals.
Baleen whale responses to a high frequency active pinger: Implications for upper frequency hearing limits
Authors: Henderson E. E. , Stimpert Alison , Debich Amanda
Published: November 2016

In order to test the possibility of using high frequency pinger tags to track baleen whales on Navy instrumented ranges, three blue (Balaenoptera musculus) and one humpback (Megaptera novaeangliaea) whales were exposed to two high frequency pingers. The pinger frequencies were 37 and 45 kHz, with estimated received levels between 106 and 134 dB re 1 μPa. The whales were monitored prior to the exposure in order to establish their behavioral state and to acclimate them to the presence of the boat. Two of the blue whales were deep feeding, while the third blue whale and the humpback whale were traveling with intermittent bouts of possible foraging near the surface. Each exposure lasted approximately 30—40 minutes, and the whales were observed for an additional two to three surfacing intervals post-exposure. None of the blue whales demonstrated any behavioral response. The humpback whale’s response was inconclusive, as other foraging animals entered the area at the same time; however, it is likely there was no response. These data may begin to provide information on the upper frequency limits of baleen whale hearing, as these species have responded to Navy sonar-like sounds at lower frequencies but similar received levels and behavioral states.
New parametric acoustic alarm proves effective at alerting wild manatees of approaching boats
Authors: Gerstein Edmund R. , Gerstein Laura
Published: November 2016

The efficacy of a bow mounted parametric acoustic alarm for alerting manatees of approaching boats was demonstrated with wild manatees in Florida. Two experimental conditions were tested; (1) boat approaches with the alarm-on, and (2) approaches with the alarm-off. Synchronized underwater acoustic buoys and aerial video recorders documented manatee behavior and acoustic conditions prior to, during, and after controlled boat approaches. 95% of the manatees during alarm-on trials elicited overt changes in behavior (avoidance reactions) prior to the boat reaching the focal manatee. In contrast, only 5% of manatees during alarm-off trials elicited any change in behavior prior to the vessel having to veer off. Changes in behavior observed prior to the boat reaching focal manatees was significantly greater (F = 471.9, df = 1, p< 0.01) during alarm-on trials. The mean distance at which manatees reacted to boat approaches during alarm-on trials was also 20 m compared to only 6m for alarm-off trials (F= 218.4 df = 1, p< 0.01). Manatees responded when received acoustic levels exceeded 12 dB of their critical ratios (behavioral threshold). Counter-intuitive to manatee protection laws, slow boats can be very difficult for manatees to detect and locate. Shallow water attenuates the dominant lower frequencies of slower moving propellers. The directional alarm assures manatees will be able to detect and locate boats at levels & distances sufficient to avoid injury. [Funded by DOD Legacy Natural Resource Management Program, USFWS Permit MA063561-4.]
Mid-frequency active sonar and beaked whale acoustic activity in the Northern Mariana Islands
Authors: Simonis Anne , Thayre Bruce , Oleson Erin , Baumann-Pickering Simone
Published: November 2016

Mid-frequency active (MFA) sonar has been associated with multiple mass stranding events of beaked whales around the world. A recent increase in military training exercises in the Mariana Archipelago corresponds with the presence of MFA sonar in the surrounding waters. We provide a quantitative report on MFA sonar and beaked whale acoustic activity detected on two autonomous acoustic recording packages deployed near Saipan and Tinian from March 2010 through December 2013. There were no detections of MFA sonar at Saipan during the 5-month deployment in 2010. On August 21, 2011, MFA sonar was detected near Saipan concurrent with a stranding event involving two Cuvier’s beaked whales (Ziphius cavirostris). After one observed day of MFA sonar activity in Saipan and Tinian in 2011, observations increased to 1 month of ongoing activity at Saipan and nearly 3 months ongoing activity at Tinian in 2012. In 2013, MFA sonar events were observed during one day at Saipan and zero days at Tinian. Received levels, sound exposure levels, and temporal descriptions of the MFA sonar events are reported along with detections of beaked whale acoustic activity. Here, we highlight the importance of ongoing passive acoustic monitoring, especially for species like beaked whales that are difficult to visually detect at sea.
The effects of wind turbine noise on male Greater Prairie-Chicken vocal output during the breeding season
Authors: Whalen Cara , Brown Mary B. , McGee JoAnn , Powell Larkin , Walsh Edward J.
Published: November 2016

At a previous meeting of the ASA, we reported that the Greater Prairie-Chicken (Tympanuchus cupido pinnatus) is, in all probability, able to detect noise produced by wind turbine installations, a finding based on turbine noise output and auditory brainstem response threshold measurements (Walsh et al., 2015). That investigation was conducted in concert with an effort to determine if noise generated by a wind turbine farm located near Ainsworth, Nebraska affects the vocal output of male prairie chickens occupying breeding grounds (i.e., leks) where they perform elaborate physical and vocal mating displays. Whalen et al. (2014) paved the way to address this question by characterizing the acoustic properties of booms, cackles, whoops and whines, the primary call types produced by male birds, at sites remote from the turbine farm. At lek sites located relatively close (<1 km) to the wind farm installation, boom and whoop production levels were higher, boom durations were shorter, whine fundamental frequency was higher, and cackle biphonation occurred less frequently than among birds occupying leks located at remote locations. Although differences in vocal characteristics were statistically significant, vocal adjustments were relatively minor and the significance of wind turbine farm noise on call acoustics will be discussed. [Funded in part by USFWS-WSFR Wildlife Restoration Project W-99-R administered by the NGPC.]