bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychophysical uncertainty estimates for real ear attenuation at threshold measurements in naive subjects
Authors: Murphy William J. , Byrne David , Witt Brad , Duran Jesse
Published: October 2013

The International Standards Organization (ISO) TC43 SC1 has directed the working groups to use the ‘‘Guide to the Expression of Uncertainty in Measurement’’ (GUM) in the development of new acoustical standards. In light of this resolution, working group 17 on hearing protection has added an annex to a proposed standard ISO4869-7 describing a subject fit method for estimation of noise reduction. Data from two laboratories, NIOSH Pittsburgh Research Lab and Howard Leight Industries, were analyzed to examine the within-test variance and between-test variance when subjects were tested using a Bekesy tracking paradigm. The NIOSH data demonstrated that the within-test variance, calculated from the reversals of the Bekesy tracks did not agree with the between test variability of the subjects’ repeated measures. This result prompted a revision of the testing software to determine the within-test variance from the midpoint of the Bekesy tracks. The revised software has been installed at both NIOSH PRL and Howard Leight facilities. This paper will compare the within-test and between-test variances determined with reversal levels and the midpoints from these two labs. The variability has been modeled with a simulated subject and Monte Carlo techniques.
Practical issues in adopting a traveling wave thermoacoustic cooler for use in a food storage refrigerator
Authors: Spoor Philip S.
Published: October 2013

CFIC/QDrive has developed a food storage refrigerator for the Army based on thermoacoustic technology. This ‘‘Phase II’’ SBIR project is a continuation of a ‘‘Phase I’’ effort that explored using a standing-wave thermoacoustic cooler for the refrigerator. The standing-wave cooler was found to be too inefficient with too low a power density to be practical, so it was switched to an acoustic Stirling, or traveling-wave thermoacoustic (regenerator based) cooler for Phase II. The major challenges of this project were adapting the Stirling-style cooler to a food storage application, and not the fundamentals of the cooler itself (the one exception being the issue of acoustic streaming). The challenges include: Running at 60 Hz (without frequency-shifting electronics), heat exchange without circulating fluids, dynamic balance, guarantee of long life, efficiency, and compactness (power density). How these challenges were met and how they drove the design, in most cases away from what would be ideal for the cycle itself, will be discussed. Time permitting, how the additional pressure of low unit cost would affect this type of product development will also be discussed. [Research supported by the U. S. Army through a Small Business Innovation Research (SBIR) grant.]
Being everything to anyone: Applicability of thermoacoustic technology in the commercial refrigeration market
Authors: Poese Matthew E. , Smith Robert W. M. , Garrett Steven L.
Published: October 2013

This talk will compare electrodynamically driven thermoacoustic refrigeration technology to some common implementations of low-lift vapor-compression technology. A rudimentary explanation of vapor-compression refrigeration will be presented along with some of the implementation problems faced by refrigeration engineers using compressor-based systems. These problems include oil management, compressor slugging, refrigerant leaks and the environmental impact of refrigerants. Recently, the method of evaluating this environmental impact has been codified to include the direct effects of the refrigerants on global warming as well as the so-called ‘‘indirect’’ warming impact of the carbon dioxide released during the generation (at the power plant) of the electrical power consumed by the refrigeration equipment. It is issues like these that generate commercial interest in an alternative refrigeration technology. However, the requirements of a candidate technology for adoption in a mature and risk-averse commercial refrigeration industry are as hard to divine as they are to meet. Also mentioned will be the state of other alternative refrigeration technologies like free-piston Stirling, thermoelectric and magnetocaloric as well as progress using vapor compression technology with alternative refrigerants like hydrocarbons and carbon dioxide.
Determination of an equivalent pore size from acoustic flow measurements
Authors: Clark Linde , Liu Jin , Garrett Steven
Published: October 2013

The hydraulic radius, rh, is defined as the ratio of a channel’s cross-sectional area to its perimeter. This parameter is important for specification of the performance of a porous medium that can be used as a regenerator in a Stirling engine or refrigerator. It is easy to calculate rh for pores of regular geometry, but difficult in more complex media. Two techniques which use oscillating flow to determine this parameter will be presented and compared. One technique extracts rh by finding the low velocity limit of the standard expression for viscous pressure drop in the Poiseuille flow regime. The other involves a plot of the nondimensional viscous flow resistance, Δpvis/Δxωρu, versus the reciprocal of the viscous penetration depth, 1/δν, in the laminar flow regime. When rh<δν, the flow behavior is frequency independent and the dynamics is characterized by rh only. When rh>δν, the flow resistance is frequency dependent and the dynamics is characterized by both rh and δν. It is possible to identify an effective hydraulic radius by equating it to the value of δν where that transition occurs. [Work supported by ONR.]
Determining which primate audiograms are reliable for comparing sensitivity in different species
Authors: Coleman Mark N.
Published: October 2013

This study investigated all known audiograms of nonhuman primates going back to the study by Elder in 1934. In total, audiograms have been published for 28 species of nonhuman primates, with macaques being the most intensively studied. The aim of this project was to determine which audiograms represent reliable measures of sensitivity by examining interlaboratory, intraspecific, and individual variability. Auditory thresholds were taken from the audiograms by digitally scanning each graph and then extracting amplitude and frequency data using SigmaScan Pro image measurement software. The precision of this method was verified by comparing extracted data with published threshold values from numerous studies. The results indicate that several patterns are consistently illustrated regardless of which techniques were used, although there is some degree of variability in audiograms produced in different laboratories. For example, several studies have found that anthropoids have better low-frequency hearing than prosimians, and nearly all monkeys show the 4-kHz dip. Another interesting finding was that a lack of low-frequency sensitivity in certain taxa (e.g., patas monkeys) cannot simply be explained as the result of using headphones instead of loudspeakers. With judicious usage, audiograms can be useful for comparing biologically meaningful differences in primate hearing patterns.
Across-frequency loudness matches with pure tones and narrow-band noises
Authors: Gregan Melanie J. , Schlauch Robert S.
Published: October 2013

Loudness matches between stimuli that differ in frequency are difficult, presumably due to the strong pitch differences which make it challenging to focus on loudness exclusively. It is hypothesized that the use of stimuli with a less salient pitch percept (but that still permit relatively frequency-specific excitation of the cochlea) would allow for more accurate across-frequency loudness matches. This would permit more stable comparisons of loudness growth between frequency regions (corresponding to normal and elevated thresholds) as is often the need in studies involving hearing-impaired subjects. In this study, normal-hearing listeners were evaluated in loudness matching tasks with two types of stimuli: pure tones and narrow bands of noise (with corresponding center frequencies). Listeners matched the loudness of a stimulus in one frequency region with a stimulus in another frequency region. The stimuli were either two pure tones, two narrow-band noises, or a pure tone and a narrow-band noise. The results will be evaluated based on predictions from an excitation pattern model and transitivity to determine if more accurate predictions are possible using narrow-band noise stimuli. [Work supported by the University of Minnesota.]
Informational masking and loudness
Authors: Roverud Elin M. , Schlauch Robert S.
Published: October 2013

In a recent study, Neff and Odgaard [J. Acoust. Soc. Am. 116, 3051–3061 (2004)] found that distracter tones with frequencies sampled randomly from Gaussian distributions interfered with frequency discrimination for target tones centered among the distracters. When the distracter tones were fixed in frequency, the interference was minimal. The goal of the present study was to examine the effect of distracter tones on the perceived loudness of a target tone. Magnitude estimations for 2.0-kHz tones as a function of level were made in isolation, in the presence of fixed-frequency distracters, and in the presence of distracters with frequencies drawn randomly from Gaussian distributions, as in Neff and Odgaard (2004). The number of distracters was either 1, 2, or 4. In a follow-up study, loudness for a frequency-modulated target tone was measured as a function of level in isolation and in the presence of unmodulated distracter tones that were also either fixed in frequency or randomly selected from a Gaussian distribution. Results will be discussed in terms of energetic and informational masking based on the loudness predictions of an excitation-pattern model. [Work supported by the UROP program, University of Minnesota.]
Development of comodulation masking release
Authors: Zettler Cynthia M. , Clarkson Marsha G.
Published: October 2013

The comodulation masking release (CMR) paradigm permits assessment of across-channel auditory processing. To evaluate the development of this phenomenon, CMR was measured in 81 children (M=8.95 years) and 20 adults (M=23.3 years). A single-interval, maximum-likelihood procedure was used to estimate thresholds in a reference condition (signal plus on-signal AM masker) and a modulated masker condition (reference condition plus eight comodulated flanking bands). CMR was defined as improvement in signal detection in the modulated masker condition relative to the reference condition. Although total CMR did not change from 7 to 10 years of age, total CMR for children (4.02 dB) was significantly less than that for adults (10.85 dB), suggesting that across-channel processing develops beyond 10 years of age. In addition, thresholds for children were significantly higher than those for adults in both the reference condition (by 6.47 dB) and the modulated masker condition (by 13.91 dB), supporting the likelihood that processing efficiency also develops beyond 10 years of age. These results suggest that both processing efficiency and across-channel cues utilized in CMR are slowly developing phenomena. [Work supported by a grant from the Georgia State University Research Program Enhancement Program.]
Modulation detection interference with periodic complex modulators
Authors: Sheft Stanley , Yost William A.
Published: October 2013

Past studies of modulation detection interference (MDI) have considered the possibility that the effect may in part relate to auditory grouping of the probe and masker. Alternatively as a cross-channel effect, MDI may be representative of informational masking. The present experiments varied modulator waveshape in attempts to distinguish the effects of auditory grouping and informational masking on MDI. In the first experiment, both the slope and duty cycle of the masker modulator varied across conditions with the task to detect either 4- or 10-Hz sinusoidal probe modulation. The effect of masker-modulator waveshape on the detection of 4-Hz probe modulation was generally consistent with change in the perceptual prominence of the masker. The 10-Hz results showed little effect of these manipulations. The second experiment utilized interrupted modulation patterns to allow for either concurrent or sequential envelope fluctuation of the probe and masker. Results showed no effect of modulation concurrency. In both experiments, significant departures from energetic masking in the modulation domain were obtained. Collectively, these results were taken to support an interpretation of the interference in terms of informational masking rather than grouping based on common modulation. [Work supported by NIDCD.]
Effects of rate-of-change pattern on the discrimination of unidirectional gliding tones with fixed frequency and time transition spans
Authors: Li Pei-Chun , Tang Shih-Tsang , Young Shuenn-Tsong
Published: October 2013

Listening experiments were designed to test the three hypotheses for detection and discrimination of glides in frequency: (1) end point sampling; (2) a weighted average method; and (3) decision based on changes in the low-frequency side of the excitation pattern. Forty-eight frequency and time transition spans were chosen. The center frequencies of testing signals were 500 Hz, 2 KHz, and 6 KHz, with frequency spans of 0, 0.5, 1, and 2 ERBs and durations of 20, 50, 200, and 400 ms. For a given transition span, the frequency difference limens for five different gliding patterns were measured, including linear chirp, quadratic and inverse quadratic sweep chirps, and FM modulated sweeps. All test patterns had the following features: (1) they are unidirectional gliding tones with increasing instantaneous frequency throughout the whole duration; (2) the phase functions are at least first-order differentiable, thus the interference of click sounds caused by fast frequency transitions are alleviated. The results showed that none of these hypotheses was able to explain the mechanism for detection and discrimination of glides in frequency well. It is speculated that, at least, both sides of the excitation patterns should be compared, and that the time-related cues could have an effect as well.
Contrastive and contextual vowel nasalization in Ottawa
Authors: Klopfenstein Marie
Published: October 2013

Ottawa is a Central Algonquian language that possesses the recent innovation of contrastive vowel nasalization. Most phonetic studies done to date on contrastive vowel nasalization have investigated Indo-European languages; therefore, a study of Ottawa could prove to be a valuable addition to the literature. To this end, a percentage of nasalization (nasal airflow/oral + nasal airflow) was measured during target vowels produced by native Ottawa speakers using a Nasometer 6200-3. Nasalized vowels in the target word set were either contrastively or contextually nasalized: candidates for contextual nasalization were either regressive or perserverative in word-initial and word-final syllables. Subjects were asked to read words containing target vowels in a carrier sentence. Mean, minimum, and maximum nasalance were obtained for each target vowel across its full duration. Target vowels were compared across context (regressive or perseverative and word-initial or word-final). In addition, contexts were compared to determine whether a significant difference existed between contrastive and contextual nasalization. Results for Ottawa will be compared with results for vowels in similar contexts in other languages including Hindi, Breton, Bengali, and French.
Spectral characteristics of voiceless fricatives in Arabic
Authors: Abu-Al-Makarem Ali S. , Cooper Donald S.
Published: October 2013

The purpose of this study was to investigate the acoustics of the voiceless fricatives of Al-Khat spoken Arabic. The FFT of the eight Arabic voiceless fricatives followed by /a: i: u:/ was investigated in four healthy adult males. The speech samples were collected in a sound-attenuated booth using a microphone with a frequency response flat 0.5 dB from 10 Hz to 11000 Hz, and digital recording. All recordings were sampled at a rate of 24 kHz. The FFT was computed for each waveform token using a 1024-point Hamming window. A 42.67-ms analysis window located in the middle of the fricative was used to compute each spectrum. The effects of vowel context on all examined acoustic parameters appeared minimal. The most effective acoustic parameter distinguishing fricatives place of articulation was spectral skewness, followed by spectral mean and spectral standard deviation of the FFT spectra. Spectral skewness distinguished the seven places of articulation for Arabic voiceless fricatives. Skewness increased as place of articulation moved from the front to the back of the vocal tract. This result extended the findings of Forrest et al. (1988) and Jongman et al. (2000) that spectral skewness reliably distinguished English fricative spectra from four places of articulation.
Acoustic and perceptual correlates of syllable weight
Authors: Gordon Matthew , Jany Carmen , Nash Carlos
Published: October 2013

Differences between languages in the stress-attracting properties of various syllable types (syllable weight) are associated with phonetic differences. Certain languages that preferentially stress CVC syllables (i.e., treat CVC as heavy) fail to display substantial vowel shortening in CVC, unlike languages that treat CVC as non-stress-attracting or light [Broselow et al. (1997)]. Furthermore, CVC has greater energy (intensity integrated over time) in languages in which it is heavy relative to languages with light CVC [Gordon (2002)]. This paper compares multiple potential acoustic and perceptual correlates of syllable weight. A representative cross section of syllable types in words uttered by speakers of four languages was recorded. In two languages (Arabic, Hindi), CVC is heavy; in two languages (Mongolian, Malayalam), CVC is light. Three measurements were taken: duration of the syllable rime, acoustic intensity integrated over the rime, and a measure of perceptual energy of the rime incorporating various factors (e.g., temporal integration and adaptation, bandpass filtering). Results thus far indicate that a measure of prominence factoring in both intensity and duration better distinguishes languages on the basis of weight criterion than a simple measure of duration. The perceptual energy measure provides a slightly better fit than acoustic energy. [Work supported by NSF.]
Identification of American English vowels by native Japanese speakers: Talker-and-token-based analysis
Authors: Nozawa Takeshi , Frieda Elaina M. , Wayland Ratree
Published: October 2013

Native speakers of Japanese identified American English vowels /i, I, ε, æ, ■, ■/ produced by four female native speakers of American English in /CVC/ contexts. Native speakers of American English served as the control group, and they outperformed the Japanese subjects in identifying all the English vowels in every /CVC/ context. In another experiment the Japanese subjects equated these English vowels with Japanese vowels. In general, English vowels were equated with phonetically close Japanese vowels, but significant talker effect was observed. The /i/ tokens equated with the Japanese long high front vowel /ii/ were much more correctly identified as /i/ than those equated with the Japanese short high front vowel /i/. These tokens were more often misidentified as /I/. The /■/ and /■/ tokens were predominantly equated with the Japanese low vowel /a/. The percent-correct identification of /■/ and /■/ was low in most of the /CVC/ contexts, and these two vowels were often misidentified as each other, and the Japanese subjects’ latency before they decided what vowel they had heard was longer when /■/ or /■/ tokens were presented. The Japanese subjects do not seem to have salient cues to differentiate /■/ and /■/.
Tuning in and tuning out: Speech perception in native- and foreign-talker babble
Authors: Van Heukelem Kristin , Bradlow Ann R.
Published: October 2013

Studies on speech perception in multitalker babble have revealed asymmetries in the effects of noise on native versus foreign-accented speech intelligibility for native listeners [Rogers et al., Lang Speech 47(2), 139–154 (2004)] and on sentence-in-noise perception by native versus non-native listeners [Mayo et al., J. Speech Lang. Hear. Res., 40, 686–693 (1997)], suggesting that the linguistic backgrounds of talkers and listeners contribute to the effects of noise on speech perception. However, little attention has been paid to the language of the babble. This study tested whether the language of the noise also has asymmetrical effects on listeners. Replicating previous findings [e.g., Bronkhorst and Plomp, J. Acoust. Soc. Am., 92, 3132–3139 (1992)], the results showed poorer English sentence recognition by native English listeners in six-talker babble than in two-talker babble regardless of the language of the babble, demonstrating the effect of increased psychoacoustic/energetic masking. In addition, the results showed that in the two-talker babble condition, native English listeners were more adversely affected by English than Chinese babble. These findings demonstrate informational/cognitive masking on sentence-in-noise recognition in the form of linguistic competition. Whether this competition is at the lexical or sublexical level and whether it is modulated by the phonetic similarity between the target and noise languages remains to be determined.
Lexical status effects on compensation for fricative assimilation
Authors: Kuzla Claudia , Mitterer Holger , Cutler Anne
Published: October 2013

In German, word-initial voiced fricatives may be devoiced if they follow /t/. This assimilation could make recognition of words beginning with /v/ harder, since there may be competing words beginning with /f/, but will not affect words beginning with /z/, since initial /s/ in German is illegal. Previous research has shown that speakers indeed produce more assimilation across word boundaries than across phrase boundaries for /z/, but inhibit the assimiliation across word boundaries for /v/. In the present study, German listeners identified the fricative continua /f–v/ and /s–z/, across word-versus-phrase boundaries, in viable-versus-nonviable contexts for assimilation. Less voicing was required for a /v,z/ judgment in viable than in nonviable assimilation contexts. This context effect was larger after a word boundary than after a phrase boundary. Within the viable-context condition, a prosodic effect appeared for /f–v/, with less voicing required for /v/ judgments after a word than a phrase boundary, but no such effect appeared for /s–z/. This asymmetry reverses the difference observed in production. Thus, listeners adjust phoneme category boundaries to compensate for prosodically conditioned variation where such adjustment is functional for word recognition, but show less compensation where adjustment would have no functional consequences.
Lexical statistics of competition in L2 versus L1 listening
Authors: Cutler Anne
Published: October 2013

Spoken-word recognition involves multiple activation of alternative word candidates and competition between these alternatives. Phonemic confusions in L2 listening increase the number of potentially active words, thus slowing word recognition by adding competitors. This study used a 70,000-word English lexicon backed by frequency statistics from a 17,900,000-word corpus to assess the competition increase resulting from two representative phonemic confusions, one vocalic (ae/E) and one consonantal (r/l), in L2 versus L1 listening. The first analysis involved word embedding. Embedded words (cat in cattle, rib in ribbon) cause competition, which phonemic confusion can increase (cat in kettle, rib in liberty). The average increase in number of embedded words was 59.6 and 48.3 temporary ambiguity. Even when no embeddings are present, multiple alternatives are possible: para- can become parrot, paradise, etc., but also pallet, palace given /r/–/l/ confusion. Phoneme confusions (vowel or consonant) in first or second position in the word approximately doubled the number of activated candidates; confusions later in the word increased activation by on average 53 third, 42 confusions significantly increase competition for L2 compared with L1 listeners.
Prosodic resolution of a syntactic ambiguity in Korean learners of English
Authors: Hwang Hyekyung , Schafer Amy J.
Published: October 2013

Research has discussed disambiguating effects of the relative strength of prosodic boundaries in native-language sentence processing (e.g., Carlson et al., 2001; Schafer et al., 2000), but not in second language processing. In this study, Korean learners of English (L2ers) and native English speakers (L1ers) listened to the initial portion of sentences with a temporary ambiguity in clause-boundary location (e.g., when that moves the square), and chose one of two visually presented disambiguating continuations [(1) it will... (2) will...]. The stimuli were quasispontaneously produced by untrained speakers, with prosody that varied in boundary strength at the correct and competing clause-boundary locations. As expected, pronunciations with the strongest prosodic boundary at the correct clause-boundary location successfully disambiguated most tokens for both L1ers and L2ers. Contrary to predictions of Carlson et al., 2001, both groups were sensitive to the size of the correct versus competing boundary strength difference: e.g., a contrast between a correct-location intonation phrase boundary and a competing-location word boundary was more disambiguating than a contrast between an intonation and an intermediate phrase boundary. Additionally, L2ers showed some difficulty in utilizing intermediate phrase boundaries as disambiguating cues, suggesting a greater learning component to intermediate than intonation phrase use for L2ers.
Assessing uncertainty in ocean acoustic inverse problems
Authors: Odom Robert I. , Ganse Andrew A.
Published: October 2013

The goal of solving ocean acoustic inverse problems is not just to find a model fitting the data. We can always fit an N-1th order polynomial to N data points, but it does not tell us much about the uniqueness, or limits placed on resolution in the presence of noise. The real goal is to develop more information than just a model that fits the data. For truly linear problems, constraints on the model information and uniqueness are characterized by the null space of the operator which maps the model to the data, the statistics are Gaussian, and the resolution matrices have well-defined meanings. Unfortunately most inverse problems of interest in ocean acoustics are nonlinear. We are faced with methods such as simulated annealing or genetic algorithms, which tell us nothing about the statistics and little about the uniqueness of our model solution, or exhaustive but numerically intensive Monte Carlo analyses. As an alternative we have examined a nonlinear filter, that is an extension of the Kalman and extended Kalman filters. We discuss the background of the ocean acoustic inverse problem for bottom properties, and how it can be addressed by employing an exact nonlinear filter. [Work supported by ONR.]
A study of the effect of sound velocity variability on received signal level
Authors: Camin H. John , Bradley David L. , Culver R. Lee , Sibul Leon H.
Published: October 2013

A detailed survey of the sound velocity profiles (SVP) in the Strait of Gibraltar was performed in 1996 over several tidal cycles. The Strait of Gibraltar is a particularly complicated environment where tides and internal waves create strong depth-, range-, and time-dependent SVP structure. In such an environment, to obtain a mean SVP, spatial and temporal averages, obscure the detail of the profile. Such averaging displays considerably more variability and randomness than a set of SVPs all taken at the same location and point in the tidal cycle. The maximum entropy (ME) method is used to estimate the probability density function (pdf) of the environmental uncertainty in two extremes: a known point in the tidal cycle with low variability, and an unknown point using the time-averaged SVPs. The uncertainty is then propagated 15 km across the strait using a parabolic equation code in order to predict the pdf’s of the received signal level. Thus, the essential environmental uncertainty is represented by the distribution of the received signal. The predictions are compared with available acoustic data. [Gibraltar data and model results generously provided by Chris Tiemann, ARL:UT, and Peter Worcester, SIO. Work supported by ONR Code 321US.
Measuring the ‘‘acoustic gaze’’ of echolocating bats, and using it to access internal processes in an active sensing system
Authors: Ghose Kaushik , Moss Cynthia
Published: October 2013

The sonar beam of an echolocating bat spatially filters the information it receives from the environment. It is proposed that the sonar beam direction can serve as an index to the cognitive state of an echolocating bat. In this respect the sonar beam may be considered an analog to visual gaze. Gaze direction spatially restricts visual information, and has been used as an index to study cognitive states of visual animals. A method to measure the sonar beam direction of a flying echolocating bat is outlined. Laboratory studies show, when presented with a single target, the bat tightly locks its sonar beam to the target before starting the high repetition rate (buzz) phase of insect pursuit. While maneuvering through a small gap, echolocating bats inspect the edges of the gap before flying through it. When presented with two targets, the bat may probe both targets with the center of its beam before changing its flight path to attack one. These studies support the hypothesis that the sonar beam of the echolocating bat may be used as an index of overt, spatial attention, much like gaze direction in naturally behaving visual animals.
Rhythm perception and production by the bottlenose dolphin
Authors: Harley Heidi E. , Crowell Sara E. , Fellner Wendi , Odell Kim , Larsen-Plott Leslie
Published: October 2013

Rhythm is an important component of many natural communication systems, but it has rarely been the focus of laboratory studies of nonhuman species. Recent cognitive studies with a bottlenose dolphin confirm that a dolphin can discriminate among six different 14-kHz 4-s acoustic rhythms at 94% accuracy, and can transfer that discrimination across multiple frequency (93%) and tempo (16%–93%) shifts. In addition, a dolphin has learned to produce six different rhythms in an object-labeling paradigm. Original training required the dolphin to produce the rhythms using a pneumatic switch that led to the in-air projection of computer-generated tones. However, the dolphin spontaneously began to produce the rhythms vocally as well. To date, the dolphin has accurately labeled five objects with unique rhythms at 87% accuracy using the switch and at 83% accuracy using his own vocalizations. Confusions at the various tempos in the perception study and the variability of some characteristics and stability of others in the production study provide insight into how dolphins represent rhythm and have implications for natural communication in this species.
What’s in a voice? Cues used by dolphins in individual recognition of signature whistles
Authors: Sayigh Laela S. , Janik Vincent M. , Wells Randall S.
Published: October 2013

Cues that bottlenose dolphins may use for individual recognition of signature whistles are (1) the individually distinctive frequency modulation patterns of whistles; and (2) voice cues caused by the anatomy of the vocal apparatus. Experiments were designed to determine whether dolphins use either or both of these cues in recognizing whistles. Temporarily held wild dolphins listened to whistles of a close relative and of a known conspecific of the same sex and similar age. To test the hypothesis that dolphins recognize the frequency modulation patterns of whistles, signature whistles were synthesized and all general voice features removed. In playbacks to 14 individuals, dolphins turned significantly more often towards the speaker if they heard the synthetic signature whistle of a close relative than that of another individual. To test the hypothesis that dolphins may also be using voice cues to recognize whistles, natural variant (nonsignature) whistles were played back, which are highly variable in contour. Preliminary analysis of seven playbacks showed no difference in responses to variant whistles of kin versus nonkin. Thus, the frequency modulation pattern of signature whistles alone provides information on the identity of the caller, and voice cues are likely not used by dolphins to identify individuals.
An explicit approach to detecting and characterizing submersed aquatic vegetation using a single-beam digital echosounder
Authors: Sabol Bruce M.
Published: October 2013

There has been a longstanding need for an objective and cost-effective technique to detect, characterize, and quantify submersed aquatic vegetation at spatial scales between direct physical sampling and remote aerial-based imaging. Acoustic-based approaches for doing so are reviewed and an explicit approach, using a narrow, single-beam echosounder, is described in detail. This heuristic algorithm is based on the spatial distribution of a thresholded signal generated from a high-frequency, narrow-beam echosounder operated in a vertical orientation from a survey boat. The physical basis, rationale, and implementation of this algorithm are described, and data documenting performance are presented. Using this technique, it is possible to generate orders of magnitude more data than would be available using previous techniques with a comparable level of effort. Thus, new analysis and interpretation approaches are called for which can make full use of these data. Several analyses’ examples are shown for environmental effects application studies. Current operational window and performance limitations are identified and thoughts on potential processing approaches to improve performance are discussed.
Intra- and interannual measurements of zooplankton biomass in the Gulf of Alaska using bioacoustical sensors
Authors: Holliday D. V. , Napp J. M. , Greenlaw C. F. , Stabeno P. J.
Published: October 2013

Sensors that monitor temperature and salinity in the sea are commonly deployed for long periods on moorings. Meteorological measurements and surface conditions such as wave height are also routinely available from surface buoys. A few moorings include a variety of optical sensors, e.g., fluorometers and spectral backscattering sensors. Ocean currents, shear, and parameters that describe mixing are sensed over long periods by autonomous acoustic Doppler current profilers (ADCP). Bioacoustical devices, used to detect and study marine zooplankton and micronekton communities, are relatively new additions to the growing suite of ‘‘moorable’’ sensors. In each of 2002, 2003, and 2004, several months of continuous bioacoustical measurements of zooplankton were made concurrently with measurements of several physical parameters and meteorological variables at a single mooring site located south of Seward, Alaska in the coastal Gulf of Alaska. Volume scattering strength spectra were collected at 20-min intervals with a TAPS-8 sensor at 20-m depth. The data allow scientists to examine complex inter- and intra-annual variations in the estimated biomass-size spectra for organism shapes typical of small zooplankton (e.g., copepods) and elongate micronekton (e.g., krill) in a unique new way. [Work sponsored by NOAA’s Coastal Ocean Program.]
Lessons learned from multifrequency acoustic studies of zooplankton and micronekton in the western Antarctic Peninsula and the Gulf of Maine
Authors: Lavery Andone C. , Lawson Gareth L. , Wiebe Peter H.
Published: October 2013

A series of acoustic surveys of zooplankton and micronekton have been performed in the Gulf of Maine (GOM), off the northeast United States, and along the western Antarctic Peninsula (WAP). Similar techniques were used to survey these regions, including multifrequency acoustic backscatter (43, 120, 200, 420, 1000 kHz), MOCNESS, CTD, VPR, and in some instances physical microstructure measurements. The GOM is characterized by heterogeneous zooplankton communities in which biomass is dominated by abundant millimeter sized copepods, but the scattering is frequently dominated by a smaller number of strong scatterers, such as shelled pteropods and gas-bearing siphonophores. Heterogeneous zooplankton communities are also observed in the WAP, but patches of comparatively large (40 mm) Antarctic krill are present and often dominate the scattering. In both regions, striking patterns are evident in the backscatter that can be related to the biological community structure and physical processes. Differences in community structure, however, strongly affect the quantitative inferences that can be made based on the acoustic data. Combining direct biological and environmental information with recently developed scattering models has allowed dominant scatterers to be identified and inferences to be made regarding the physical factors influencing backscatter variability, though only under limited conditions. Highlights from these studies and lessons learned regarding our ability to interpret multifrequency acoustics are presented.
A new tool for real-time acoustic species identification of delphinid whistles
Authors: Oswald Julie N. , Rankin Shannon , Barlow Jay , Lammers Marc O.
Published: October 2013

Acoustic species identification studies generally focus on postprocessing of field recordings using multivariate statistics such as classification tree analysis (CART). When CART was used to classify whistles of nine delphinid species recorded in the eastern tropical Pacific ocean (n=908), 51% were correctly classified to species (versus 11% expected by chance). These results led to the development of a new automated system to allow real-time acoustic species identification in the field. This matlab-based tool automatically extracts variables from whistles manually selected from a real-time scrolling spectrograph (ishmael software) and runs classification statistics (CART and discriminant function analysis). Output includes predicted species identification with a certainty score and alternate identifications with certainty scores. The original CART results were based on classification of one whistle at a time. With the new system, identification decisions are based on multiple whistles, resulting in higher classification success. This new tool allows species distribution data to be collected using a towed hydrophone array when visual efforts are compromised (e.g., darkness, high sea states). It may also prove valuable for studies utilizing bottom-mounted recorders, where visual species identification is not possible. Additionally, through automation, this tool reduces the time required for analysis of voluminous acoustic data.
High-frequency acoustic tracking of odontocetes at the Southern California Offshore Range (SCORE)
Authors: Hursky Paul , Abawi Ahmad T. , Porter Michael B. , Hildebrand John A. , Wiggins Sean M. , Soldevilla Melissa , Sauter Allan W.
Published: October 2013

The SCORE site, located near San Clemente Island, is known to be abundant in marine mammals, and is the site of frequent naval operations, making it an ideal site to study what impact man-made activities may have upon these creatures. In August 2004, an experiment was performed to collect both visual and acoustic observations of odontocetes at the SCORE site. Odontocete vocalizations consist of clicks and whistles. The clicks are very wideband (often 100 kHz), so times of arrival can be measured with extremely high resolution, which makes clicks attractive waveforms for multipath ranging and depth estimation. Although the whistles are narrowband, their fundamental frequency often ranges over tens of kilohertz, so these too can be processed as if they were wideband. We will present results of processing excerpts from several weeks of data recorded on a high-frequency horizontal line array deployed from the FLIP research vessel. Bearing tracks of individuals and groups from a number of different species will be correlated and compared with visual observations. In addition, we will discuss the possibilities for range and depth estimates derived from the multipath arrivals observed in the clicks and whistles.
Factors which influence acoustic surveys of marine mammals
Authors: Rogers Tracey L. , Ciaglia Michaela B. , Cato Douglas H.
Published: October 2013

Traditionally, many marine mammal populations have been estimated by visual surveys. These count the animals that are available—either seals hauled-out on the ice or whales at the water’s surface. Corrections are then made to include the animals that were not seen either because they were in (seals) or under (whales) the water. However when the majority of the animals in a population are not available to a visual survey this approach may be less effective. So we investigated whether acoustic surveys offered promise for estimating the distribution and abundance of Antarctic pack-ice seals. Four acoustic surveys were conducted (October 1996, 1997; December 1997, 1999) between longitudes 600E and 1500E. Surveys were bounded to the south by fast-ice, shelf-ice or the Antarctic continent and to the north by the edge of the pack-ice. No crabeater seals were heard. Leopard and Ross seals were highly vociferous in December coinciding with their breeding season. To predict the area surveyed we modeled transmission loss and measurements of received background levels. To identify the number of seals calling we modeled calling behavior. A preliminary estimate of 0.13 male leopard seals/km2 was calculated which is in the high-density range described from the literature.
Comparison of high intensity focused ultrasound (HIFU) exposures using empirical and backscatter attenuation estimation methods
Authors: Civale John , ter Haar Gail , Rivens Ian , Bamber Jeff
Published: October 2013

Currently, the intensity to be used in our clinical HIFU treatments is calculated from the acoustic path lengths in different tissues measured on diagnostic ultrasound images of the patient in the treatment position, and published values of ultrasound attenuation coefficients. This yields an approximate value for the acoustic power at the transducer required to give a stipulated focal intensity in situ. Estimation methods for the actual acoustic attenuation have been investigated in large parts of the tissue path overlying the target volume from the backscattered ultrasound signal for each patient (backscatter attenuation estimation: BAE). Several methods have been investigated. The backscattered echo information acquired from an Acuson scanner has been used to compute the diffraction-corrected attenuation coefficient at each frequency using two methods: a substitution method and an inverse diffraction filtering process. A homogeneous sponge phantom was used to validate the techniques. The use of BAE to determine the correct HIFU exposure parameters for lesioning has been tested in ex vivo liver. HIFU lesions created with a 1.7-MHz therapy transducer have been studied using a semiautomated image processing technique. The reproducibility of lesion size for given in situ intensities determined using BAE and empirical techniques has been compared.
Story of the patent intitulated (in translation from the French), ‘‘Feature of wind instrument permitting the generation of special effects in real time.’’
Authors: Causse Rene
Published: October 2013

This presentation will focus on the history of a patent taken out in 1996 by my colleagues F. Laloe, A. Ducoureau, F. Terrier, and myself (France Tlcom patent). This patent is related to a system that allows the wind instrument’s pitch to be controlled by means of a mechanical device comprising a foot pedal for the musician and a cable connected to the embouchure of the instrument. There is no predefined semitone or quarter-tone position. The system extends the current musical range and performance capabilities of the instrument chosen for a realization, a clarinet, by inserting in the instrument an additional length. It is possible to change not only the pitch of tones but also to soften their timbre, producing a tone similar to that of early instruments. This type of special effect is well suited to contemporary, jazz, and popular music. The device is adapted to any type of clarinet and the principle can conceivably be extended to other wind instruments. In this presentation, the device and its derivatives shall be described, and its musical applications illustrated by sound examples. A critical approach to the different levels of reading of the patent will be presented.
Access to patents as sources to musical acoustics inventions
Authors: Brock-Nannestad George
Published: October 2013

Patents are important sources for the development of any technology. The paper addresses modern methods of access to patent publications relating to musical acoustics, in particular the constructions of instruments and components for instruments, methods for tuning, methods for teaching, and measuring equipment. The patent publications available are, among others, from the U.S., England, France, Germany, Japan, Russia, and the date range is from ca. 1880 to the present day. The two main searchable websites use different classification systems in their approach, and by suitable combination of the information it is possible to target the search efficiently. The paper will demonstrate the recent transfer of inventions relating to physical instruments to electronic simulations, and the fact that most recent inventions were made by independent inventors. A specific example is given by discussing the proposals for improved pipe organ and violin constructions invented in Denmark in the 1930s by Jarnak based on patented improvements for telephone reproducers.
Roadmap to quieter highways
Authors: Corbisier Christopher
Published: October 2013

Research in Europe, as documented by an FHWA/AASHTO European Scan Tour held in May 2004, and recent activity in Arizona and California, has fostered much interest in ‘‘quiet pavements.’’ On September 14–16, 2004, an FHWA sponsored Roadmap to Quieter Highways workshop was held at Purdue University. Participants were from the disciplines of pavement, safety, and noise from FHWA, State departments of transportation, industry (paving associations, general contractors, tire, and vehicle manufacturers), and academia. After several breakout sessions in the areas of policy, construction, maintenance, analysis (measurement and prediction), research, and design, the group had identified the knowledge gaps and developed a plan to fill those gaps. Several activities have been implemented based on the Roadmap to Quieter Highways. An Expert Task Group was formed to provide a draft provisional standard for the measurement methodologies, e.g., source, wayside, pavement absorption. A Tire/Pavement 101 workshop is being developed to educate pavement practitioners in noise concepts and noise practitioners in pavement concepts. A Tire/Pavement Noise clearinghouse is being developed as a one-stop location for all current tire/pavement noise or quiet pavement activities. Several research studies have been started and a second workshop will be held in 2006 to assess progress of the Roadmap.