bluuebunny/crossref_metadata_2025 huggingface dataset:
Soundscape analyses for ecosystem conservation
Authors: Gasc Amandine
Published: June 2017

Large scale spatial and temporal analyses help to appreciate and subsequently act to avoid or reduce ecosystem disturbances. For example, remote sensing imagery aid in understanding large scale dynamics of ecosystems; however, the capture of the animal community component of the ecosystem is challenging. Soundscape analyses provide a new insight into animal community and ecosystem ecological levels with a detailed temporal resolution, considered here as a complementary approach. Therefore, the focus of this presentation is to: (1) summarize the recent research advances in the estimation of composition and dynamics of animal acoustic community and (2) present recent research utilizing acoustic community in disturbance detection and its potential for ecosystem restoration. Initial results from the scientific community provide robust elements to support the use of soundscape measurements to evaluate disturbance impacts on animal community and natural ecosystems. Additionally, interest from natural area managers in application of soundscape techniques is largely confirmed. However, additional research is still necessary to develop robust and calibrated methods and tools for concrete biological conservation action. Three objectives are highlighted as future directions of this research: (1) develop soundscape metrics and improve their interpretation, (2) improve the understanding of soundscape drivers, and (3) develop soundscape-based disturbance indicators.
How often is human auditory detection in natural environments limited by our absolute hearing thresholds?
Authors: Fristrup Kurt M. , Joyce Damon
Published: June 2017

The National Park Service (NPS) has collected long-term sound level measurements from more than 800 sites, using equipment that measures 1 second, 1/3rd octave band levels. One-third octave bands approximate the critical bands for the human auditory system, and the initial motivation for collecting these data was to predict the levels at which incoming aircraft noise would be audible. Here, we will compare the nominal human threshold of hearing—expressed in 1/3rd octave bands—with an appropriate summary of the background or residual sound level of each environment. Several procedures have been recommended for estimating the residual sound level, or the sound level that remains after energy from nearby and transient sound sources is removed. The merits of alternative procedures for estimating residual sound levels will be assessed. The NPS data show that human hearing has evolved to take advantage of the quietest conditions that occur in all but the very quietest environments, across a substantial portion of the audible spectrum. For species whose hearing is up to 10 dB less sensitive than humans, they will be operating in a masked hearing regime in the majority of locations and hours.
Spatio-temporal distribution of beaked whales on Canada’s East Coast
Authors: Martin Bruce , Delarue Julien , Kowarski Katie , Moors-Murphy Hilary , Mills Flemming Joanna
Published: June 2017

Beaked whales represent some of the least understood marine mammals worldwide with the movements and distribution of many species largely unknown. Around eastern Canada current knowledge is limited to the eastern Scotian shelf and northern bottlenose whales. The acoustic signals of the beaked whale species are recognizable and sufficiently unique to be candidates for passive acoustic monitoring. Thirteen deep-water recorders located along the shelf break off Eastern Canada from Bonnécamps Canyon (42.5 N) to Southern Labrador (55.3 N) collected acoustic data near-continuously from Aug 2015 to July 2016. A minimum of one of every 20 minutes were recorded at 250,000 samples per second to monitor for the presence echolocations clicks of odontocetes, including beaked whales. An automated detector, validated by manual analysts, identified the presence of endangered Northern Bottlenose whales (Hyperoodon ampullatus), Cuvier’s (Ziphius cavirostris), and special concern Sowerby’s beaked whales (Mesoplodon bidens). The presence data were analyzed to determine the occurrence and residency durations of beaked whales throughout the geographic range studied. We then studied the influence of currents, sea ice, surface temperatures, chlorophyll, distance to the 1000 m isobath, background noise and anthropogenic noise on the whales’ acoustic occurrence. Acoustic studies such as this allow us to gain further insights on the occurrence of these notoriously difficult to study species.
Seasonal acoustic ecology of beluga and bowhead whale core-use areas in the Pacific Arctic
Authors: Stafford Kathleen , Castellote Manuel , Guerra Melania , Berchok Catherine L.
Published: June 2017

The acoustic ecology of Arctic marine mammals is driven by anthropogenic, biotic, and abiotic factors each of which may influence the behavioral ecology of each species. The acoustic environment of bowhead (Balaena mysticetus) and beluga (Delphinapterus leucas) whales in three core-use regions of the Pacific Arctic was examined during the months in which both species occur in these regions. The Anadyr Strait region in winter was dominated by the signals of bowhead whales, walrus and bearded seals. In Bering Strait in late fall and winter, wind noise predominated in November but once the region was ice-covered, bowhead and walrus were the main sources of noise. Barrow Canyon in late summer and fall was the only region in which anthropogenic sources overlapped with both whale species. Overall, ambient noise levels were low in the Pacific Arctic when compared to other ocean basins in which anthropogenic noise dominates low frequencies. However, climate change-driven increases in open water are leading to rising noise levels from increased human use of the Arctic, increased storminess, and increased presence of vocal subarctic whales. These “new” sources of sound may be altering the underwater soundscape and possibly influencing the acoustic ecology of Pacific Arctic cetaceans.
Variability in coral reef soundscapes, spatiotemporal differences, biophysical and behavioral drivers, and associations with local biota
Authors: Mooney T. Aran , Lillis Ashlee , Kaplan Maxwell B. , Suca Justin , Lammers Marc
Published: June 2017

Coral reefs harbor some of the highest biodiversity on the planet. Their rich ecoacoustic soundscape may provide a way to track both animal activities and community level structure. To do so, it is critical to identify how reef soundscapes are influenced by biotic and abiotic parameters, and establish how soundscapes change over time and across habitats. Here we present results from 18 coral reefs in the U.S. Virgin Islands and Maui, Hawaii, with the overall goals to quantify soundscape variability across multiple spatial and temporal scales (days to years), test how soundscape parameters relate to local biological communities, and address how biophysical parameters (light, temperature, and rugosity) influence these eco-soundscapes. Acoustic measurements were made in-tandem with benthic and fish visual surveys. Analyses were carried out using high and low-frequency bands corresponding to the primary soniferous taxa on reefs, snapping shrimp and fish. Overall, these results indicate that certain acoustic metrics can be linked to visual survey results. Snapping shrimp exhibit complex spatiotemporal patterns, with strong diel rhythms shifting over time and varying substantially over short spatial scales. Furthermore, long-term recordings are necessary to provide a robust baseline measurement of acoustic variability and better quantify changes in coral reef ecosystems.
Listening for right whales off Brazil: Present knowledge and future research
Authors: Dombroski Julia R. , Parks Susan , Groch Karina R. , Flores Paulo A. , Sousa-Lima Renata S.
Published: June 2017

In the Southwest Atlantic, a key southern right whale wintering ground is found off southern Brazil. Aiming to collect reference information on the acoustic ecology of right whale mother-calf pairs in the region, we used two complementary passive acoustic monitoring methods. Recordings from autonomous archival devices were used to obtain the description of pairs’ vocal repertoire: call classes were established, temporal and frequency parameters of calls were measured and reported, and the existence of a diel pattern of vocal activity was investigated. Calling rate and contextual call usage were obtained through synchronized behavioral observations and acoustic recordings made using a dipping two-unit linear array. Current knowledge about the species vocal behavior off Brazil allows an increment in the use of PAM methods as a research tool. Therefore, our plans for future research include the use of multistory tags, sound propagation, and playback experiments, and long-term deployment of autonomous devices along the whale’s concentration area. Future results will contribute to enhancing the knowledge on the species communication system and will aid habitat management decisions.
Analysis of fin whale vocalizations south of Rhode Island
Authors: Giard Jennifer , Miller James H. , Potty Gopu R. , Newhall Arthur , Lin Ying-Tsong , Baumgartner Mark F.
Published: June 2017

Fin whale vocalizations were recorded south of Rhode Island during late summer through early fall of 2015 using a number of underwater recording systems. These systems were deployed to monitor broadband noise, including pile driving, from construction of the Block Island Wind Farm. Two vertical hydrophone array moorings were deployed in approximately 40 m of water each with four hydrophones. Additionally, a tetrahedral array was deployed in about 30 m of water just above the seabed. The tetrahedral array consisted of four hydrophones spaced 0.5 m apart. The spacing between each of these recording systems was approximately 7.5 km. 20-Hz fin whale vocalizations were recorded numerous times on all of the sensors both during and after construction was completed. An analysis and localization effort of these signals was performed to estimate the source level, directionality and the track of the whale over the period of the vocalizations. The results of this analysis will be discussed. [Work supported by the BOEM.]
Concurrent passive and active acoustic observations of high-latitude shallow foraging sperm whales (Physeter macrocephalus) and mesopelagic prey layer
Authors: Pedersen Geir , Storheim Espen , Sivle Lise D. , Godø Olav Rune , Ødegaard Lars Alf
Published: June 2017

Using echosounder and hydrophone data from the Lofoten-Vesterålen Cabled Ocean Observatory (LoVe, N 68 °54.474’, E 15 °23.145’, 258 m depth) collected in 2015, we are able to concurrently quantify sperm whale (Physeter macrocephalus) shallow foraging behavior and the behavior of the mesopelagic prey layer. Click rate and type was detected by the passive acoustics while active acoustics monitored the distribution and vertical and horizontal movement of the prey organisms in the water column. In one instance a diving sperm whale was also detected by the active acoustics allowing TS measurements and estimation of diving speed and angle. Additional data such as ocean current and proximity of vessels, in addition to vessel noise measurements, further allowed us to examine potential links between oceanographic conditions and noise on sperm whale behavior and foraging and the presence of prey and whales. The results demonstrate the additional information obtained by combining data from active and passive acoustic sensors. The first part of the LoVe cross-disciplinary ocean observatory was established in 2013, and the extension is planned for 2017/2018 covering the Norwegian shelf to approximately 2500 m depth. This will further expand the observatories capabilities for underwater acoustic monitoring and targeted scientific studies.
Non-linear analysis as a hierarchal classification scheme for vocalizing marine biologics
Authors: Matthews Cameron A. , Matthews Anthony , Ceparano Anthony
Published: June 2017

Many ocean animals use acoustic communications. Breeding, territorial aggression, and hunting actions often include some form, often complex, and can provide actionable intelligence on the vocalizing animals' intent. As a means of considering the linear features of the time series and the corresponding spectral and cyclic frequency content as it pertains to different classes of animals, a hierarchy termed periodic linear, periodic non-linear, and aperiodic non-linear structural vocalization is considered. To demonstrate the application of such a hierarchy, known vocalizations from the red hind grouper (Epinephelus guttatus), the four lined grunter (Pelates quadrilineatus), the spiny lobster (Panulirus argus) are considered and analyzed for grouping according to the hierarchy based on their time, spectral, and cyclic signal content. Finally, a vocalization collected from the invasive Lionfish (Pterois volitans), understood at the time of publication to be the first such recorded instance, is exercised against the hierarchy to show membership identification.
Acoustic environment of North Atlantic right whales in the Southeastern United States
Authors: Parks Susan , Read Andrew J. , Nowacek Douglas P.
Published: June 2017

North Atlantic right whales are an endangered species of baleen whale that migrates along the east coast of the United States, with winter calving grounds located in the coastal waters off Florida and Georgia. This study investigated the acoustic environment experienced by individual right whales swimming through this habitat though the use of suction cup attached acoustic recording tags. Nineteen tag attachments were made between 2014 and 2016. These tags documented a range of sounds from the right whale acoustic environment, including calls produced by the tagged whale, sounds produced by conspecifics, as well as sounds from other biological (fish and dolphin) and anthropogenic sources. The call rates of individual whales were relatively low, with calls typically produced in short duration bouts. Sounds from other biological sources, particularly fish and dolphin, and anthropogenic sources, particularly vessels, were common. This project presents an initial step toward characterizing the acoustic environment experienced by individual whales to allow future comparisons to stationary acoustic recordings in the same habitat.
Redefining species boundaries for acoustically and morphologically distinct species of swamp breeding frilled tree frogs (Kurixalus appendiculatus) in the Southwestern Philippines
Authors: Broadhead Taylor , Grismer Jesse , Brown Rafe
Published: June 2017

Combining analysis of male advertisement calls, multivariate analysis of continuous morphological variation, biogeographic information, and a multilocus phylogenetic estimate of relationships, we reconsider species boundaries within Philippine populations of the frilled tree frogs Kurixalus appendiculatus. Within the archipelago, the species spans several recognized biogeographic boundaries, with highly divergent genetic lineages isolated within formally recognized, geologically defined, faunal subregions. Given this distribution, at least four possible taxonomic arrangements are possible, varying from one to four possible evolutionary species. Simultaneous consideration of fixed external phenotypic character differences, continuously varying morphometric data, evolutionary relationships, biogeography, and statistically significant differences in mating calls converges on a solution of two Philippine species. We advocate for more widespread, regular, and deliberate sampling of acoustic data to diminish challenges for future studies, where we anticipate the validation of other likely taxonomic arrangements by differences in advertisement calls.
Passive acoustic monitoring finds concurrent use of an artificial reef in the New York Bight by foraging humans and odontocetes (Tursiops truncatus)
Authors: Wirth Colin , Warren Joseph
Published: June 2017

Passive acoustic recordings collected during summer 2015 at an artificial reef (sunken barge) south of Long Island, New York revealed regular visitation by groups of delphinid odontocetes. Detected signals included social (whistles) and foraging (short-interval echolocation) signals of odontocetes, as well as signals specific to bottlenose dolphins (Tursiops truncatus) and two known prey species. Visual observations, high broadband noise levels, and presence of acoustic signatures specific to boats indicated heavy use of this site by recreational fishers. Boat detections were significantly more frequent on weekends and between sunrise and sunset. Dolphin detections did not vary diurnally and were significantly lower on weekends, possibly due to avoidance of persistent noise disturbance. Bottlenose dolphins produce low-frequency, narrow-band signals that are highly susceptible to masking by boat noise. However, no significant difference was observed in the duration, average peak frequency, or frequency range of these signals when boat noise was present or absent. Our findings demonstrate the benefits of passive acoustic techniques in monitoring soniforous users (including humans) of artificial reef habitats in these waters. Attraction of both human fishers and odontocetes to artificial reefs may increase direct human-predator interactions as well as indirect ecological competition.
Preliminary measurements of passive acoustics in Lake Superior
Authors: Austin Jay A.
Published: June 2017

In July 2016, a hydrophone was deployed for eight days in 54 m of water in the western arm of Lake Superior. This is, to the best of our knowledge, the first recording of passive acoustic information in a large lake. The signal is dominated by noise from passing ships (30-100 Hz) and by surface winds (broad spectrum). Noise from passing ships drops off as approximately r-6, suggesting that there are significant transmission losses associated with reflections off of the bottom. The signal associated with wind is highly correlated with wind speed as measured at a nearby buoy. Intermittent “clicks” look similar to burbot calls previously observed, and appear to occur only in the absence of ship noise. This suggests a potential behavioral response to ambient acoustic energy. Ray tracing experiments suggest the acoustic environment within the lake will change drastically as the lake transitions from summer stratified conditions to unstratified, and again when inverse winter stratification sets in.
Musicological indices for soundscape ecological analysis
Authors: Bellisario Kristen M. , VanSchaik Jack T. , gasc amandine , Bedoya Carol , Omrani Hichem , Pijanowski Bryan C.
Published: June 2017

Soundscape ecologists have collected sound recordings from large-scale studies that are difficult to analyze with traditional approaches and tools. Natural soundscapes are complex and contain a diverse mixture of biological, geophysical, and anthropogenic sources that span similar frequency bands and often lack a discernible fundamental frequency. Selecting features that are responsive to signals without fundamental frequencies and that are capable of classification for multi-layer signals, or polyphonic textures, is a challenging task in soundscape ecology. Spectral timbral features in various combinations have been shown to discriminate in music classification problems, and lend support to our hypothesis; timbral features in soundscape analysis may detect and identify patterns that are inherently related to order-specific communication in frequency bands shared by biological, geophysical, and anthropogenic sounds. Combined timbral feature extractions provides a new level of information about acoustic activity within a soundscape. Current soundscape metrics assess biodiversity, functional diversity, and acoustic complexity, but may be missing crucial information if we compare musical acoustic analysis techniques used to identify genres and structures in music. This new method provides a relational approach to understanding sound event interactions within soundscapes, refining quantifiable soundscape data, and improving the resolution with which it is analyzed.
Acoustic competition of Serranids at a fish spawning aggregation
Authors: Cameron Katherine , Semmens Brice , Pattengill-Semmens Christy V. , Gittings Steve , McCoy Croy , Širović Ana
Published: June 2017

Many fish species are known to produce stereotyped calls during spawning activities. It has been hypothesized that these calls play a vital role in coordination during this critical period. Competition for acoustic space can result in masking of calls and, as a result, may limit their function. Acoustic niche separation could be a solution to avoid acoustic competition for species that co-occur in a geographic area. The data from passive acoustic arrays deployed in Little Cayman, Cayman Islands, between 2015 and 2017 during the spawning of one of the largest aggregations of Nassau grouper (Epinephelus striatus) have been analyzed to explore acoustic niches in Serranids. At least three other vocal Serranid species are known to spawn at this location during the same time as Nassau grouper: red hind (E. guttatus), black grouper (Mycteroperca bonaci), and yellowfin grouper (M. venenosa). Call characteristics, such as the peak frequency, bandwidth, source level, and pulse period, were analyzed for all distinct calls from these species. In addition, temporal and spatial patterns of those calls were evaluated, allowing a detailed understanding of the communication space and acoustic competition potential for these cohabitating species.
Bioacoustic analysis of penguin vocalization classification for Newport Aquarium educational exhibit
Authors: Wysocki Bethany , Scheifele Peter M.
Published: June 2017

Newport Aquarium in Newport, Kentucky, strives to engage its visitors in the educational importance of aquatic life and conservation. Through a variety of research programs and volunteerism, the aquarium promotes local and global efforts for animal advocacy. An important component of their organization is the diversity of education offered to its daily patrons and guests. The purpose of this project was to examine the acoustic and behavioral characteristics of penguin vocalizations in an effort to create an educational exhibit targeting school-age visitors. Vocalization samples of the 5 penguin species housed at Newport Aquariums’ Kroger Penguin Palooza exhibit were recorded at various times of the day, over a 5-month period. In addition to the recordings of the various penguins, behavioral characteristics were also noted in correspondence with the individual call and species. The calls were spectrally analyzed using SpectraPLUS software system, looking specifically at frequency, power, and sound pressure levels. Spectrogram plots were also documented to identify penguin vocalization variances and species identification. A Hidden Markov Model used this information to categorize and cluster vocalizations in an effort to classify them. The information extracted about the vocalizations and acoustic variances will be used for educational and exhibit purposes for the aquarium.
Characterizing Chilean blue whale vocalizations with digital acoustic recording tags: A test of using tag accelerometers for caller identification
Authors: Saddler Mark , Bocconcelli Alessandro , Hickmott Leigh S. , Chiang Gustavo , Landea-Briones Rafaela , Bahamonde Paulina A. , Howes Gloria , Sayigh Laela
Published: June 2017

Vocal behavior of blue whales (Balaenoptera musculus) in the Gulf of Corcovado, Chile, was analyzed using digital acoustic recording tags (DTAGs). We report the occurrence of Southeast Pacific type 2 (SEP2) calls, which exhibit peak frequencies, durations, and timing consistent with previous reports. We also offer the first description of tonal downswept (D) calls for this population. Since being able to accurately assign vocalizations to individual whales is fundamental for studying communication and for estimating population densities from call rates, we further examine the feasibility of using DTAG accelerometers to identify low-frequency calls produced by tagged whales. We cross-correlated acoustic signals with simultaneous tri-axial accelerometer readings in order to analyze the phase match as well as the amplitude of accelerometer signals associated with low-frequency calls, which provides a reliable method of determining if a call is associated with a detectable acceleration. Our results suggest that vocalizations from nearby individuals are also capable of registering accelerations in the tagged whale’s DTAG record. We cross-correlate acceleration vectors between calls to explore the possibility of using signature acceleration patterns associated with sounds produced within the tagged whale as a new method of identifying which accelerometer-detectable calls originate from the tagged animal.
Build-up effect of auditory streaming in budgerigars (Melopsittacus undulatus)
Authors: Cai Huaizhen , Screven Laurel A. , Dent Micheal L.
Published: June 2017

When listening to a rapid tone sequence of the form ABA-ABA-ABA-… (where A and B are two tones of different frequencies and “-” indicates a silence interval), listeners may either hear one coherent “gallop” of three tones grouped together or two separate auditory streams (one high frequency, one low frequency) appearing to come from two sound sources. Research on humans indicates that the tendency to perceive two streams can be built up as exposure time increases. Neural recordings in European starlings show build-up effects of auditory streaming too. A lack of behavioral data on the build-up effect in nonhumans make it difficult to draw parallels between animals and humans. The present research aims to behaviorally validate the build-up effect of auditory streaming and factors that may influence the effect in nonhuman animals. Four budgerigars were tested in a categorization task using operant conditioning. “Streaming” categorization increased as the frequency separation increased. Additionally, in some frequency separations, as the sequence duration increases, the probability of “streaming” categorizations reported by the budgerigars is higher. These results indicate that budgerigars experience a build-up effect of auditory streaming behaviorally, and this effect is influenced by, but may not be limited to, different frequency separations.
Acoustic characterization of sound production by the Pot-Bellied Seahorse (Hippocampus abdominalis)
Authors: Hutton Brittany A. , Scheifele Peter M. , Johnson Laurel
Published: June 2017

Sound production is a critical component of predator-prey interactions. In order to understand why seahorses produce sound in various instances (i.e., courtship, feeding, and stress), we must first quantify the acoustic parameters of the signal. Seahorses produce sound with a stridulation of the supraoccipital bone and the coronet by moving their head upwards in a motion that is referred to as a “snick.” The acoustic signal that accompanies this head movement is called a “click.” We set out to analyze the sound parameters of the largest seahorse species, Hippocampus abdominalis, housed at the Newport Aquarium. Adult and juveniles were tested each individually and allowed one hour to acclimate to an isolated tank. Feeding on brine shrimp (Genus: Artemia) was observed with video and audio recordings that were collected for approximately 12 minutes. SpectraPLUS was used to evaluate the frequency, intensity, and number of clicks present in the audio recordings. The video footage allowed for analysis of the presence of the snick. By characterizing the sound production in this species of seahorse we are able to begin to answer the question of the purpose for the click and snick behavior.
Biotic factors influencing sound production patterns by two species of snapping shrimp (Alpheus heterochaelis and A. angulosus)
Authors: Perelman Jessica N. , Panyi Apryle , Lillis Ashlee , Mooney T. Aran
Published: June 2017

Withdrawn at author's request.
Comparison between the marine soundscape of recreational boat mooring areas with that of a pristine area in the Mediterranean: Evidence that such acoustic hot-spots are detrimental to ecologically sensitive habitats
Authors: Ruiz Juan Francisco , Gonzalez-Correa Jose Miguel , Bayle-Sempere Just , Ramis Jaime , Rountree Rodney A. , Juanes Francis
Published: June 2017

We investigated the potential to use passive acoustics to access the impact of recreational boat mooring areas on ecologically sensitive habitats in the Western Mediterranean. One important consequence of the tourist industry in the region is that it targets the most pristine and ecologically sensitive habitats. Underwater sounds were recorded in mooring areas in Ibiza, Formentera and Tabarca harbors during high use and low use seasons and compared to recordings in the Tabarca Marine Protected area. At each location, we recorded sounds during 20 min at three different sites, for three random sampling times during the day. The percent of time occupied by selected biological (drums and croaks) and anthropogenic sounds (boat and mooring chain noises), and call rates of selected fish sounds were measured and compared among sites and seasons. Biological sounds contributed significantly less to the soundscape in mooring areas during the tourist season, and to the reserve in both seasons. Our study demonstrates the critical need for research on the impact of acoustic noise “hot spots” such as recreational mooring areas on marine and freshwater soundscapes.
Auditory sensitivity of various areas of the head to underwater acoustical stimulation in odontocetes
Authors: Sysueva Evgeniya , Nachtigall Paul E. , Pacini Aude F. , Pawloski Jeff , Allum Craig , Supin Alexander
Published: June 2017

Sensitivity to the local underwater acoustic stimulation of the ventro-lateral head surface was investigated in a bottlenose dolphin (Tursiops truncatus). The stimuli were tone pip trains of carrier frequencies ranging from 32 to 128 kHz with a pip rate of 1 kHz. Auditory evoked potentials (the rate following responses) were recorded. For all the tested frequencies, a low-threshold region was revealed at the lateral side of the middle portion of the lower jaw. This result differed from that obtained in a beluga whale, Delphinapterus leucas (Popov et al., JASA 2016, 140: 2018) revealed a maximal sensitivity region next to the medial side of the middle portion of the lower jaw. The comparative analysis of these data and their extrapolation to all odontocetes in generally is discussed.
Psychophysical audiogram of a California sea lion (Zalophus californianus) listening for airborne tonal sounds in an acoustic chamber
Authors: Reichmuth Colleen , Sills Jillian , Ghoul Asila
Published: June 2017

Many species-typical audiograms for marine mammals are based on data from only one or a few individuals that are not always tested under ideal conditions. Here, we report auditory thresholds across the frequency range of hearing for a healthy, five-year-old female California sea lion identified as Ronan. Ronan was trained to enter a hemi-anechoic acoustic chamber to perform a go/no-go audiometric experiment. Auditory sensitivity was measured first by an adaptive staircase procedure and then by the method of constant stimuli. Minimum audible field measurements were obtained for 500 ms frequency-modulated tonal upsweeps with 10% bandwidth and 5% rise and fall times. Thresholds were measured at 13 frequencies: in one-octave frequency steps from 0.1 to 25.6 kHz, and additionally at 18.0, 22.0, 36.2, and 40.0 kHz. Sensitivity was greatest between ~0.9 and 23 kHz, with best hearing of 0 dB re 20 μPa at 12.8 kHz. Hearing range, determined at the 60 dB re 20 μPa level, extended from ~0.2 kHz to 38 kHz. Sensitivity was comparable to that of three sea lions tested in similarly controlled conditions, and much better than that of two sea lions tested in less controlled conditions. [Work supported by ONR.]
Differential temporal structures in mouse ultrasonic vocalizations relay sex and age information about the producer
Authors: Calbick Daniel , Castellucci Gregg A. , McCormick David A.
Published: June 2017

Mice produce a variety of ultrasonic vocalizations (USVs) during social interactions among conspecifics. However, it remains unclear which features of these calls mice utilize to distinguish one type of USV from another. In this study, we examine male courtship USVs, neonatal isolation USVs, and female social contact USVs, and find that the temporal structure of the calls alone is sufficient for a high level of discriminability. Specifically, we found that males produce temporally distinct short and long duration USVs with resulting short and long duration call intervals, while females produce nearly exclusively short USVs with short call durations. Young pups were found to produce medium duration USVs with long call intervals only. Interestingly, as the pups aged, their USV durations and call intervals decreased and approached values observed in juvenile male courtship USVs. Therefore, the gross USV rhythmic structure carries a high degree of information about both sex and age of the producer, and may be utilized by mice during call discrimination. These findings are reminiscent to some pinniped species, who face similar challenges in the transmission of their calls (i.e., a high density of calling conspecifics), who also use gross temporal features to distinguish call types.
Neurobehavioral studies of Dumetella carolinensis in the Northeast United States
Authors: Badiey Babak
Published: June 2017

Behavioral studies of Grey Catbirds (Dumetella carolinensis) have been conducted over two seasons using data collection, including playback calls, to learn about the neurobehavior of mimicking birds. First birds are identified by their signals, and detailed signal processing techniques are used to examine the characteristics of the bird calls using call time-frequency signal dispersion and relating them to behavior. Catbird songs often include frequency-modulated notes sweeping through a wide range of frequencies and different sweeps related to their syrinx and are identified in the signals. The broadband signals are grouped into similar song patterns and are checked versus the bird's position, the background noise, and weather conditions. These experiments are conducted in controlled background noise conditions to quantify the effect of noise on the birds. It is found that background noise causes production of louder calls while it does not affect that playback behavioral response of the bird.
Bioacoustic monitoring station in underwater sculpture
Authors: Spence Heather R.
Published: June 2017

In the waters surrounding Cancun, pressures from development, tourism, and shipping threaten the second largest coral reef system in the world. Passive bioacoustic monitoring provides information about presence and activity of marine life and other environmental information, including during the night and inclement weather. The development and deployment of underwater reef-forming art structures provided a unique opportunity to listen to the stages of growth. Starting in 2012, an Ecological Acoustic Recorder was used to sample sounds at “The Listener” sculpture site in the Punta Nizuc Marine Protected Area in Quintana Roo, Mexico. Snapping shrimp and fish sounds were prevalent as well as sounds from boat motors. Diel patterns were characterized to inform management practices and assess efficacy of nighttime noise restrictions.
Non-whistle sounds used in bottlenose dolphin aggressive interactions recorded on digital acoustic tags
Authors: Sayigh Laela , Dziki Austin , Janik Vincent , Kim Edward , McHugh Katherine , Tyack Peter L. , Wells Randall , Jensen Frants H.
Published: June 2017

Bottlenose dolphins (Tursiops truncatus) produce a wide array of sounds, including clicks for echolocation and whistles for communication, both of which have been studied intensively. However, sounds other than whistles and echolocation clicks have received less attention, probably due to their high variability. These include the class of sounds loosely described as “burst pulses,” which in several studies of dolphins under human care have been linked to aggressive interactions. Few studies have been carried out in the wild, beyond those describing basic acoustic parameters of sounds. Here we use acoustic and movement recording tags (DTAGs) placed simultaneously on both members of pairs of free-ranging bottlenose dolphins in Sarasota Bay, Florida, USA, to investigate acoustic behavior during aggressive interactions between male alliances and female-calf pairs. Using unsupervised clustering and discriminant function analysis on parameters such as frequency content, duration and rise time, we separate three different sound types recorded during aggressive interactions: broadband burst pulses, highly resonant cracks, and low-frequency narrowband quacks. We demonstrate how these different signal types appear to be used in the context of male-to-female aggression and/or male-male coordination. These characterizations may assist researchers analyzing acoustic recordings in assigning behavioral states to animals that are largely out of sight.
Integrating dual frequency side-scan sonar data and multibeam backscatter, angular response and bathymetry, for benthic habitat mapping in the Laganas Gulf MPA, Zakinthos Isl., Greece
Authors: Fakiris Elias , Dimas Xenophon , Georgiou Nikolaos , Christodoulou Dimitrios , Rzhanov Yuri , Papatheodorou George
Published: June 2017

The preferred procedure nowadays for benthic habitat mapping is combining marine acoustic and ground truthing methods, with the former ones tending to be the swath sonars, such as the Multi Beam Echo Sounders (MBES) and the Side-Scan Sonars (SSS). Both above acoustic systems, in conjunction with an extensive underwater video footage, were employed to map in detail benthic habitats in the marine area of Laganas Gulf in the National Marine Park of Zakynthos Isl., Greece, including key protected habitats such as P.oceanica beds and coralligenous formations. Object oriented seafloor classification was achieved taking advantage of the multi-layer information available, including the two individual frequencies of SSS and the MBES backscatter, angular response, and bathymetry data. The extracted statistical derivatives regarded: (1) textural analysis of the multi-frequency backscatter imagery, (2) angular range analysis of the MBES backscatter, as well as (3) application of various bathymetric indices. Those derivatives were classified individually or fuzzed together, to explore the rate of improvement when choosing one system or another and to investigate their best combinations and practices towards valid seafloor classification. Benthic habitat classification has been comprehended using the NATURA and EUNIS classification schemes to be compatible with the EU regulations.
Mapping methane gas seeps with multibeam and split-beam echo sounders
Authors: Weber Thomas C.
Published: June 2017

Modern multibeam echo sounders (MBES), which are most widely used for collecting high-resolution bathymetry and seabed imagery, often have the capability of recording acoustic backscatter from the full water column. This capability has enabled several new applications for MBES including the study of marine organisms, the quantification of suspended sediments, imaging physical oceanographic structure, and the detection, localization, and characterization of methane gas seeps. Split-beam echo sounders (SBES) are widely used in fisheries applications, but have a similarly diverse range of other applications. Here, we review the use of both MBES and SBES systems for mapping different phenomena in the water column, with a focus on mapping methane gas seeps. In doing so, we attempt to highlight the many advantages of these systems, but also discuss some of the limitations including the masking of targets by high seafloor reverberation levels in MBES systems. We also discus some of the challenges associated with wide bandwidth SBES systems, including our attempts to maintain a frequency-independent field-of-view using constant-beamwidth transducers.
Acoustic observations of the fish assemblage during a multibeam hydrographic survey of a cod spawning area
Authors: Gurshin Christopher W.
Published: June 2017

A two-day hydrographic survey using a dual-head Kongsberg EM3002 multibeam echosounder was conducted to map the seafloor features within 9 square kilometers of the Gulf of Maine Cod Spawning Protection Area, where Atlantic Cod (Gadus morhua) were known to concentrate during their spring spawning season. Acoustic backscatter from the water column collected during the first day of this survey was used to describe the fish assemblage associated with a corridor bounded by elevated features when the area was closed to commercial fishing. During the survey, a bottom trawler under a research permit made six tows where fish were observed by the hydrographic survey vessel. The species assemblage was dominated (>80%) by Atlantic Cod. Acoustic observations from the second day, when the area was open to an active commercial fishery, were compared to those during the fishing area closure. Echo statistics and position in the water column were used to characterize categories of fish detections and associate them spatially to the seafloor features and temporally to fishing closure.
Sediment sound speed dispersion inferences from broadband reflection coefficient measurements
Authors: Holland Charles W. , Pinson Samuel , Olson Derek R.
Published: June 2017

The frequency dependence, or dispersion, of sound speed in marine sediments has been a topic of considerable interest and remains a research topic. While experiments on well-sorted sediments (having a narrow range of grain sizes) show promising concordance with theory, the more typical continental shelf sediments exhibit a rather wide range of grain sizes. A major experimental challenge is to measure in-situ sound speed over a sufficiently wide frequency range, such that the underlying mechanisms (e.g., viscous or friction) that control intrinsic dispersion can be isolated. Broadband 1.8-10 kHz seabed reflection measurements in the TREX13 experiment show a critical angle that is very nearly frequency independent. When effects of wavefront curvature, sound speed gradients, layering, and roughness are taken into account, this observation indicates that sediment sound speed must also be nearly independent of frequency. [Research supported by the ONR Ocean Acoustics Program.]
Development of a new acoustic mapping method for eelgrass and macroalgae using a multi-beam echo-sounder
Authors: Norton Ashley R. , Dijkstra Semme J.
Published: June 2017

Eelgrass and various macroalgae play important roles in temperate coastal ecosystems, including as habitat for many species, and as a bio-indicator for water quality. However, in turbid or deeper waters, the optical remote sensing methods commonly used for mapping eelgrass do not provide the necessary range for analysis. We are developing a methodology for detecting and characterizing eelgrass and macroalgae beds using water column backscatter data from multi-beam echosounder systems. We are specifically developing methods to map the maximum depth limit, percent cover, functional type (i.e., macroalgae or eelgrass) and canopy height of the beds, because these are difficult to characterize using existing optical and acoustic methods. Water column data was collected using an Odom MB1 sonar in 2014 and 2015 over a variety of vegetated sites selected to represent a range of conditions: dense/sparse eelgrass, long/short eelgrass, mixed macroalgae and eelgrass, eelgrass on muddy or hard substrates, etc. In addition to sonar data, drop camera data was collected, and data from a regional aerial mapping program also exist for comparison. Initial data analysis shows good agreement between drop camera and sonar detections, and patches as small as 1m2 and as short as 20 cm are detectable.
Ultrafast ultrasound localization microscopy
Authors: Errico Claudia , Couture Olivier , Tanter Mickael
Published: June 2017

The resolution of ultrasound imaging is limited by the classical wave diffraction theory and corresponds roughly to the ultrasonic wavelength (from 0.2 to 1 mm for clinical applications). Current methods for in vivo microvascular imaging are limited by trade-offs between the depth of penetration and resolution. Inspired by the optical localization techniques (FPALM), we developed the technique ultrafast ultrasound superlocalization (uULM) where the resolution is not limited by the wavelength (Couture et al. 2011, Desailly et al. 2013). The use of ultrafast ultrasound acquisitions, based on plane wave transmissions at the rate of thousand frames per second, enabled the separation of million microbubbles achieving a resolution of about 8 μm at 12 mm depth for the vascular structure of the rat brain in-vivo (Errico et al., 2015). Moreover, we have lately demonstrated that by combining acoustic vaporization of composite droplets and rapid ultrasound monitoring, ultrasound drug-delivery can also be attained with subwavelength precision (Hingot et al., 2016).
Effects of a mono-disperse bubble population on the cumulative phase delay between second harmonic and fundamental component
Authors: Demi Libertario , van Hoeve Wim , van Sloun Ruud J. , Wijkstra Hessel , Mischi Massimo
Published: June 2017

A positive cumulative phase delay (CPD) between the second-harmonic and fundamental component of ultrasound waves is a marker specific to ultrasound contrast agents. Dynamic contrast-enhanced ultrasound images generated by using this marker have already been reported in the literature. However, only results obtained with a poly-disperse contrast agent (SonoVue®) have been presented. In this study, we compared CPD values obtained with standard SonoVue® and with a mono-disperse contrast agent (MDCA); the latter consisted of 4-μm microbubbles produced with a MicroSphere Creator®. The same as with SonoVue®, MDCA microbubbles were made of SF6 gas encapsulated in a monolayer phospholipid shell. An ULA-OP research platform equipped with an LA332 linear-array probe was employed to image a dedicated gelatin flow-phantom. Different frequencies (1.5 to 3.5 MHz) with a mechanical index of 0.7 were used. Images were reconstructed in a tomographic fashion, and the contrast to tissue ratio (CTR) evaluated. When imaging at 1.8 MHz (close to the resonance frequency of a 4 μm microbubble), results show significantly stronger CPD values for the mono-disperse microbubbles, resulting in an overall CTR improvement by 5 dB. In conclusion, mono-disperse UCAs can be used to improve imaging performance of cumulative phase delay imaging.
The dynamic of contrast agent near a wall under the excitation of ultrasound wave
Authors: Mobadersany Nima , Sarkar Kausik
Published: June 2017

In this study, the behavior of contrast agents near a wall subjected to ultrasound wave have been studied numerically using boundary integral method. Contrast agents are gas filled microbubbles coated with layer of lipid or protein to prevent them against dissolution in the blood stream. Under the exposure of ultrasound wave, the contrast agents oscillate and collapse. The oscillation or collapse of the contrast agent near a wall generates shear stress resulting in the perforation of the wall to better uptake of large molecules and drugs by the tissue. In this research, we are studying the dynamics of the contrast agent, the surrounding velocity and pressure filed and the shear stress exerted on the wall due to bubble collapse for different shell rheology parameters, different standoff distances, different excitation pressures and frequencies. The study has been conducted at excitation pressures beyond the threshold of inertial cavitation where the bubble forms a jet during the collapse phase. The strain softening exponential elasticity model has been used for the interfacial rheology of the coating.