bluuebunny/crossref_metadata_2025 huggingface dataset:
Flight demonstration project for low-sonic boom design technology
Authors: Murakami Akira
Published: October 2013

Japan Aerospace Exploration Agency (JAXA) has promoted a supersonic technology research program including flight demonstration since 1997. In this program, JAXA is now planning the new flight demonstration project ‘‘Silent Supersonic Technology Demonstrator Project (S3TD).’’ One of the targets of this project is to demonstrate the low sonic boom aircraft concept to reduce sonic boom intensity by 50% as compared with conventional configuration and to modify the sonic boom signature for not only front shock boom but also the rear shock one. JAXA will develop a new flight demonstrator that is an unmanned vehicle of approximately 3 tons in weight and 13 m in length, and then JAXA will make flight trials by 2012. Now JAXA is designing the base-line configuration, using the CAD-based Automatic Panel Analysis System that we have developed. The shock overpressure of the S3TD base-line configuration is estimated to be about 0.23 psf for front shock and 0.21 psf for rear shock, corresponding to about 50% intensity as compared with those of N-wave signature estimated by the first-cut method. The robustness of the low boom signature is also considered. The rear shock boom signature is so sensitive to flight condition that some small device is installed around the aft deck.
Perceptual movement of sounds moved up or down through multiway loudspeakers set up perpendicularly
Authors: Agastuma Yu , Miyasaka Eiichi
Published: October 2013

Perceptual movements of sounds fed through eight loudspeakers perpendicularly set up were investigated. The loudspeakers, which were mutually separated by 30 cm, were set up immediately in front of 15 observers positioned 4.5 m distant from the loudspeakers. They were required to answer the start point of the loudspeaker through which they perceived that the sound was output at the start, and the end point of that loudspeaker. The results show that the ascension or descension of the sound images was perceived when 1/3 octave bands of noises with center frequencies of 1, 4, and 8 kHz were linearly moved up or down in the range from 60 to 150 cm. The results also show that the perceived moving distance depends on the moving speed, becoming longer than the physical distance at speeds of 10 and 20 cm/s, and converging to the physical distance concomitant with higher moving speed, irrespective of the center frequencies. [Work supported by SCAT.]
Localization of text-to-speech voices in a virtual speech display
Authors: Rubin Gordon
Published: October 2013

An auditory display using high-quality text-to-speech (TTS) voices is presented to a group of individuals. Subjects are asked for their impression of the source direction of a synthesized talker in a nonreverberant environment. Location is coded using a set of nonindividualized head-related transfer functions (HRTFs). Many years of research in binaural technology provide comparative data for the localization ambiguities inherent in such presentation (e.g., front-back confusion). These ambiguities are characterized for stimuli generated by a mature concatenative speech synthesis system. An initial attempt is made to quantify the perceptual significance realized by a binaural-model-motivated speech synthesizer.
Using localization cues to track one of two concurrent sound sequences
Authors: Rivenez Marie , Guillaume Anne , Pellieux Lionel , Delor Christelle
Published: October 2013

This study examined how localization, via binaural cues, can help the tracking of a sound sequence, interleaved with another sound sequence, across time. The ability to track a sequence was investigated using a temporal irregularity detection task. The temporal irregularity was inserted into a regular isotone sequence (target sequence) interleaved with an irregular sequence of same frequency (masker sequence). Performances were at the chance level when there was no interaural difference between the sequences. In experiment 1, large improvements of performances were found using several interaural level (ILD) or time (ITD) differences between the two sequences. Manipulating the masker sequence ILD and maintaining the signal-to-noise ratio constant in the best ear (experiment 2) or using a monaural presentation of the sequences (experiment 3), data showed that the effect of ILD could not be explained by a monaural processing (best or bad ear listening). Finally, experiment 4 revealed that the effect of binaural cues on tracking a sound sequence was mainly produced by the perceived localisation differences induced by the interaural differences rather than by the physical differences. These results suggested that binaural cues may influence sound sequence tracking via a spatial attention mechanism.
Comparison of pre- and post-cueing in a multiple-source sound localization task
Authors: Simpson Brian D. , Brungart Douglas S. , Gilkey Robert H. , Iyer Nandini , Hamil James T.
Published: October 2013

Although most sound localization research has examined the ability of listeners to determine the location of a single sound presented in a quiet (typically anechoic) environment, most real-world listening situations are more complex, with multiple simultaneous sounds. Here, an initial experiment, designed to examine localization in multisource environments, is described. Listeners judged the location of a target signal (speech or environmental sound, presented normally or time-reversed) masked by up to four simultaneous sounds. In each block of trials, the observation interval was either preceded by, or followed by, a cueing interval, during which the stimulus to be localized was identified. It was expected that these two approaches would lead to different answers, as the associated tasks presumably address different listening strategies (i.e., analytic listening versus monitoring). The results indicate that, in all conditions, localization errors increase as the number of simultaneous sources increases. Moreover, performance degrades more rapidly in the post-cue condition than in the pre-cue condition. Surprisingly, this difference occurs for as few as two simultaneous sources, suggesting that there is a substantial cost when listeners are asked to remember what sounds were present and where those sounds were located in a complex auditory environment. [Work supported by AFOSR.]
Rate limitation and onset dominance in the discrimination of high-frequency click trains with dynamic envelope ITDs
Authors: Stecker G. Christopher
Published: October 2013

Several studies have shown that binaural processing at high carrier frequency is limited to relatively slow modulations, suggesting profound consequences for binaural processing of high-rate electrical stimulation by cochlear implants (CIs). In this study, we measured normal-hearing-envelope ITD thresholds for Gaussian impulses (clicks) with 4000 Hz carrier frequency and 2 ms total duration (BW approximately 900 Hz) and for 16-click trains with rates of 100, 200, or 500 pps. For click trains, right-leading ITDs were static (condition RR), increased linearly from diotic (condition 0R), or decreased linearly toward diotic (condition R0). Thresholds were calculated from the largest ITD in each stimulus (i.e., the onset of R0 or offset of 0R trains). Consistent with previous results for normal hearing and bilaterally implanted subjects, thresholds were strongly dependent on ICI. Low-rate (100 pps) thresholds improved for 16-click trains relative to single clicks in all conditions, while high-rate (500 pps) thresholds were similar to single clicks for RR and R0 stimuli. In condition 0R, 500 pps ITD thresholds were elevated and comparable to monaural rate discrimination. The results suggest an inability to lateralize high-rate stimuli in the absence of onset ITDs and have important consequences for binaural information processing with cochlear implants.
Evidence for active suppression of masker locations in spatially separated multitalker conditions
Authors: Allen Kachina , Carlile Simon , Alais David , Froud Karen
Published: October 2013

Three experiments tested active suppression of masker locations. Using a nonword corpus, spatial release from masking (SRfM) of 3.1 dB was calculated using masked thresholds (67%) of colocated and separated (20 deg) masker and target. Mirrored conditions were completed, with results pooled between hemispheres. In experiment 1, 80% of trials were masked 20 deg left of the central target. Random (10%) trials played targets at the expected masker location, and (10%) at the symmetrically opposite side, with maskers 20 deg laterally displaced. Thresholds revealed 2.6-dB reduction at the masker location compared to symmetrically opposite (null) locations. Experiment 2 used a central target with masker played 20 deg to the left in 80% of trials. Random (20%) trials (unexpected) played the masker at the symmetrically opposite side. Target thresholds were reduced by 2.1 dB when masker location was unexpected. Both experiments indicate active suppression of expected masker locations, suggesting masker suppression may contribute to SRfM. Experiment 3 played 80% of trials with maskers 20 deg left of the central target. Random (10%) trials played the target 40 deg to the left of center, and (10%) at the symmetrically opposite side, with the masker 20 deg laterally displaced. Reduced target thresholds (2.0 dB) indicated that masker suppression also extends laterally, beyond the expected masker location.
Investigating the buildup of precedence effect using reflection masking
Authors: Hartcher-O’Brien Jess , Buchholz M. , Buchholz M.
Published: October 2013

The auditory processing level involved in the build-up of precedence [Freyman et al., J. Acoust. Soc. Am. 90, 874–884 (1991)] has been investigated here by employing reflection masked threshold (RMT) techniques. Given that RMT techniques are generally assumed to address lower levels of the auditory signal processing, such an approach represents a bottom-up approach to the buildup of precedence. Three conditioner configurations measuring a possible buildup of reflection suppression were compared to the baseline RMT for four reflection delays ranging from 2.5–15 ms. No buildup of reflection suppression was observed for any of the conditioner configurations. Buildup of template (decrease in RMT for two of the conditioners), on the other hand, was found to be delay dependent. For five of six listeners, with reflection delay=2.5 and 15 ms, RMT decreased relative to the baseline. For 5- and 10-ms delay, no change in threshold was observed. It is concluded that the low-level auditory processing involved in RMT is not sufficient to realize a buildup of reflection suppression. This confirms suggestions that higher level processing is involved in PE buildup. The observed enhancement of reflection detection (RMT) may contribute to active suppression at higher processing levels.
Practice effects in comodulation masking release
Authors: Zettler Cynthia M. , Clarkson Marsha G.
Published: October 2013

Substantial research has explored the acoustic factors influencing comodulation masking release (CMR), but the impact of practice has not been addressed. The current study evaluated the effect of experience on CMR thresholds. Ninety-eight adults listened to CMR stimuli through headphones once a week for 3 weeks. CMR was measured as the difference in threshold between a reference condition with one 20-Hz-wide amplitude-modulated noise band centered on a 1000-Hz, pure-tone signal, and a modulated masker condition having eight additional noise bands comodulated with the on-signal band. Thresholds were estimated in a single-interval, maximum-likelihood procedure. Hierarchical linear modeling tested the effect of practice on thresholds and CMR. Analyses indicated that thresholds improved significantly with practice (p<0.001) for both masking conditions. On average, reference thresholds improved 5.41 dB per visit (SE=0.703), and modulated masker thresholds improved 3.15 dB per visit (SE=0.495). Total CMR decreased significantly (p<0.01) by 1.98 dB per visit (SE=0.701), most likely because performance in the reference condition improved more than performance in the modulated masker condition. Results indicate that practice improves performance in CMR masking conditions and that total CMR decreases with experience.
Timing perception of tonal sequences connected with glides
Authors: Tanaka Satomi , Tsuzaki Minoru , Kato Hiroaki
Published: October 2013

When we hear continuous sound signals, we extract the timing between each segment although each segmental boundary is acoustically unclear. In order to investigate on which points we perceive the temporal structures in sound signals, perceptual experiments were conducted to measure the sensitivity in detecting the temporal deviation by using sound signals containing frequency glides. The following question was raised: What would provide a more effective cue to detect a change in the temporal structures, the starting point or the ending point of glides? Five segments of steady parts, of which high and low were alternated, were connected with four frequency glides, while the amplitude was fixed. By randomizing the duration of glide parts and adjusting the duration of steady parts compemsatively, one can exclusively add a certain degree of fluctuation on the starting point or ending point of glides. The task was to detect a temporal deviation from an isochronous structure. The thresholds of detection were measured within three ranges of the center frequency. The detectability tended to be better under the starting point condition than under the ending point condition. The results were discussed in relation to a computational model of event detection. [Work supported by JSPS.]
Human performance in detecting audio-visual asynchrony
Authors: Kohlrausch Armin , Par Steven van de , Eijk Rob van , Juola James F.
Published: October 2013

The perception of audio-visual delays by human observers is typically characterized by two quantities: the point of subjective equality (PSE) and the sensitivity to asynchrony. The PSE can be derived from a temporal order judgment (TOJ) procedure or from the outcomes of a synchronous-successive response paradigm. Sensitivity to asynchrony is derived from the steepness of the response curve in the TOJ paradigm. In this contribution we present data that show that PSE estimates derived from TOJ measurements are much more variable across observers than those based on synchronous-successive data. Two synchronous-successive methods were used with different response categories: (1) two categories: asynchronous, synchronous, and (2) three categories: audio first, synchronous, video first. Both synchronous-successive methods yielded similar results. A slight influence of stimulus type on PSE estimates derived from synchronous-successive data was observed. To conclude, we analyzed discriminability values obtained with a two-alternative forced-choice procedure. Discriminability is better near the edge than in the middle of the synchronous response category. This suggests that categorical perception might play a role in audio-visual synchrony perception.
An upper bound on the temporal resolution of human hearing
Authors: Kunchur Milind N.
Published: October 2013

This work obtained an upperbound of about 5 ms for the temporal resolution of hearing by studying human discriminability for bandwidth restriction by low-pass filtering. While low-pass filtering affects both the spectrum and temporal definition of the signal, the spectral changes in this experiment fall below the known just noticeable differences, so that the threshold seems to reflect the neural temporal-discrimination of the auditory system, rather than its ability to distinguish spectral cues based on tonotopic excitation patterns. The present result shows that human temporal resolution extends down to time scales much shorter than found in the past. Rough estimates of the expected resolution, based on convergencies in the cochlear nucleus and subsequent stages, yields values in a range that is consistent with the present experimental result.
Acoustic and spectral correlates of lexical stress
Authors: Okobi Anthony O.
Published: October 2013

Acoustic and spectral parameters that differentiate between primary and nonprimary stressed vowels were determined using two-syllable novel words with identical syllable compositions. The location of the high focal pitch accent within a declarative carrier phrase was varied using an innovative object naming task that allowed for a more natural and spontaneous manipulation of phrase-level accentuation. Results showed that when the high focal pitch accent was on the novel word, vowel differences in pitch prominence, intensity prominence, and vocal tract filter corrected amplitude of the first harmonic (H1*) accurately distinguished primary from nonprimary stressed vowels. Vowel differences in first formant frequency, the spectral approximations of open quotient, H1*-H2*, and first formant bandwidth, H1*-A1*, also correlated with lexical stress under this condition. Correlates of lexical stress that were differentiating under all conditions tested were spectral tilt, H1*-A3*, noise at high frequencies, and duration. Furthermore, results indicated that these lexical stress vowel differences were augmented when the high focal pitch accent was on the novel word. This became apparent after a formula was devised to correct for the masking effect of phrase-level accentuation on the spectral tilt measurement. [Work partially supported by NIH T32-DC00038.]
Intonational distinctions between sentence types in North Kyungsang Korean
Authors: Lee Hye-Sook
Published: October 2013

As a lexical pitch accent language, North Kyungsang Korean seems to display a very restricted distribution of intonation. This paper investigates intonational differences between statements and questions in North Kyungsang Korean. In particular, a variety of f0 targets are compared between the sentence types, including pitch accent f0 peak, utterance-final edge, pitch range, and f0 valleys. Besides the acoustic analyses, perceptual identification tests are performed to test whether apparently diverging acoustic cues are perceptually significant. Based on ANOVA tests, it turns out that NK Korean questions can be significantly different from statements with respect to the utterance-final edge f0 and the relative f0 and timing of the rightmost f0 valley. Specifically, questions have higher f0 values at the right edge and higher and earlier occurrences of the rightmost f0 valley. Further, the forced-choice identification tests, whose input materials are manipulated in the similar set of acoustic variables, show that only the utterance-final edge f0 is a strong perceptual cue to distinguish between questions and statements. In the meantime, the comparison of yes/no questions and wh-questions demonstrates that there is no common acoustic factor with which the two types of questions are significantly distinguishable.
The degree of word-initial low tone in Japanese: Syntactic boundaries and speech rate
Authors: Tokizaki Hisao
Published: October 2013

This study investigates the nature of word-initial low tone in Japanese. It will be shown that the degree of low tones depends on the speech rate and the number of syntactic boundaries between the word and the immediately preceding word. It will be argued that the phenomena can be explained naturally by boundary mapping from syntax onto phonology (Tokizaki, 1999, 2006). Pierrehumbert and Beckman (1988) and Selkirk and Tateishi (1988) argue that minor phrases are demarcated by initial low tone in unaccented words. Selkirk et al. (2003) argue that degree of low tone depends on whether the word is located at the left edge of a maximal projection of the lexical head (XP). The analysis of spoken data will be presented. Radio news and recited sentences are analyzed by Praat. The pitches of the first and the second mora of a word are measured and compared with the pitch of the high tone in the preceding word. The pitch difference of the first mora and the second is calculated. The result shows that our analysis makes a better prediction for the degree of word-initial low tone than previous analyses. [This project is supported by Grant-in-Aid for Scientific Research, JSPS, 2006.]
Variability and mismatch: Speakers’ cues and listeners’ cues
Authors: Hirose Yuki
Published: October 2013

The present study questions the natural assumption that the types of cues speakers use are common to those that listeners utilize. The left- versus right-branching ambiguity (LB/RB) in Japanese complex NPs such as the blue CD-genitive case was the material of interest. In a production study, accompanying visual contexts were manipulated with respect to visual ambiguity: whether there was only one possible target (referent) object corresponding to either RB or LB in each scene, or objects corresponding to both analyses were present in each scene and therefore the ambiguity remains in the visual scene. Phonetic analyses of the collected utterances revealed that when the visual information eliminated the ambiguity, the difference between the LB- and RB-intended utterances was modest and appeared mainly in F0 cues; when the ambiguity remained in the visual context, the prosodic manipulation was made mainly on durational cues. Those utterances were then fed to a perception study. A multiple regression analysis indicated that the cues contributing to RB/LB distinctions in listeners mainly showed up on durational cues, suggesting that most types of cues manipulated by speakers who were not aware of the ambiguity did not contribute to listeners’ comprehension.
A perception study of syntactic disambiguation using resynthesized speech
Authors: Sugahara Mariko , Hirose Yuki
Published: October 2013

It is already well known that when a preceding word (W1) is accented, the following word (W2) is likely to undergo a postaccent downstep. Such a downstep is especially evident in a left-branching structure (henceforth LB) as in [[W1 W2] W3], while it is mitigated in a right-branching structure (henceforth RB) as in [W1 [W2 W3]]. That is, ups and downs of the F0 peak of W2 disambiguate the RB and the LB structure when a postaccent downstep is available (Selkirk and Tateishi, 1991; Kubozono, 1993, Hirose, 2005). Two questions, however, emerge. One is whether or not the magnitude of W3’s downstep would ever contribute to the branching disambiguation. The other is what would happen when all words are unaccented, i.e., when no postaccent downstep is available. We carried out a perception study using resynthesized speech as stimuli, to examine those questions. Our results show that neither the W3 peak values of a postaccent environment nor the W2 peak values of an unaccented environment had significant effect on the LB vs. RB disambiguation. Such results will be compared with Hirose’s (2005) production and perception study on spontaneous speech.
On the prosody control characteristics of nonverbal utterances and its application to communicative prosody generation
Authors: Li Ke , Greenberg Yoko , Shibuya Nagisa , Sagisaka Yoshinori , Campbell Nick
Published: October 2013

In this paper, prosodic characteristics of nonverbal utterances were analyzed using an F0 generation model proposed by Fujisaki aiming at communicative speech generation. From the analysis, the different distributions of F0 generation parameters have been observed for prototypical four dynamic patterns (rise, gradual fall, fall, and rise&down). Since former works have shown that these differences can correspond to their impressions (such as confident-doubtful, allowable-unacceptable, and positive-negative) expressed by multi-dimensional vectors, we tried to make a computational model from impression vector to F0 generation parameters. By employing a statistical optimization technique, we have achieved the mapping from impression vectors to prosody generation parameters. Perceptual evaluation tests using neutral words have confirmed the effectiveness of the mapping to provide communicative speech prosody. [Work supported in part by Waseda Univ. RISE research project of ‘‘Analysis and modeling of human mechanism in speech and language processing’’ and Grant-in-Aid for Scientific Research B-2, No. 18300063 of JSPS.]
Analyses of fundamental frequency contours for Japanese utterances that express several degrees of four emotions—joy, sadness, anger, and fear
Authors: Kawatsu Hiromi , Ohno Sumio
Published: October 2013

To give synthetic speech richer expression, prosodic features of utterances with various kinds of emotions were analyzed. Utterances that express four basic emotions with several degrees were collected as speech material: joy, sadness, anger, and fear. The fundamental frequency contours are analyzed based on a model for the process of generation. Changes in controlling parameters of the model were examined with regard to degrees of emotion. The baseline frequency increases as degrees of emotion increase. Especially for sadness and anger, its tendency is remarkable. Regarding phrase commands, the rate of occurrence increases as the respective degrees of emotion increase. The rates are affected by the kind of branch boundary in the grammatical structure and the number of morae from the immediately preceding phrase command. The change of the amplitude of phrase commands depends on the kind of position of grammatical structure. For the accent commands, timings of their onsets and offsets are almost constant for degrees of emotion. They depend on the accent types of prosodic words. The magnitude of the accent commands changes as degrees of emotion increase depending on the positions of prosodic words from the beginning of the utterance.
Testing the implicit prosody hypothesis: Data from English
Authors: Jun Sun-Ah
Published: October 2013

One of the recent theories in sentence processing hypothesized that the prosodic phrasing implicit to a certain syntactic structure determines how speakers interpret the structure. According to this implicit prosody hypothesis (IPH; Fodor, 1998, 2002), in a structure of relative clause (RC) with a complex head noun, speakers/languages tend to prefer low attachment (i.e., an RC is modified by the adjacent head noun) if the prosodic break adjacent to RC is smaller than that between the head nouns. However, speakers/languages tend to prefer high attachment (i.e., an RC is modified by the nonadjacent head noun) if the prosodic break adjacent to RC is greater than that between the head nouns. Jun and Koike (2003) and Jun and Kim (2004) have shown that Japanese and Korean speakers who prefer high attachment produced a bigger prosodic break adjacent to RC than between the head nouns, confirming the IPH. The current study examines the prosodic phrasing of English sentences to investigate whether speakers of American English, known to prefer low attachment, would produce a larger prosodic break between the two head nouns than that between the RC and the adjacent head noun. Data from 30 speakers will be discussed. [Work supported by UCLA Faculty Grants.]
Speech timing: Final lengthening and syllable reduction in cerebellar pathology
Authors: Casper Maureen A. , Geibel Jennifer
Published: October 2013

The production of prosodic prominence may be considered the hallmark of normal speech motor control. Two theoretical views predict different relations between duration and formant and fundamental frequencies. The dynamic view of coordination predicts a disassociation between time and movement amplitude, while the clock theory of cerebellar movement poses a monotonic relation between duration and frequency. Phrase-final lengthening and syllable reduction each were measured across a prosodic contrast design for the acoustic measures of syllable duration, F0, F1, and F2. The speech characteristics of normal and cerebellar ataxic speakers were compared. In support of gestural dynamics, and following the kinematic findings for normal speakers, the acoustic findings showed longer duration and reduced frequency for phrase-final lengthening, and shorter duration and reduced frequency for syllable reduction. Cerebellar speakers produced longer durations for both events and increased variability for formant and fundamental frequency. This dissimilarity between normal prosodic production and that of cerebellar speakers implies a dynamic relationship between time and articulatory movement. In contrast to normal speech production, cerebellar speech is markedly slow and fails in the rapid adaptation to reduce frequency in phrase-final and reduced syllables.
Correlations between voice F0 responses and manual reaction times to auditory feedback pitch shifts
Authors: Madonia Dana , Burnett Theresa
Published: October 2013

There appear to be two types of voice F0 responses to voice auditory feedback pitch manipulations: early, opposing responses, and later responses that vary across subject and task. The purpose of this study was to determine whether either type correlates with volitional motor abilities. Subjects vocalized /u/ into a microphone while listening to their voice fed back over headphones. Subjects also pressed a joystick button as rapidly as possible upon hearing any experimenter-generated auditory feedback pitch shift. Pitch shift stimuli were 50 cents upward or downward (randomized), and 100-ms duration. Voice was recorded, F0 extracted, smoothed, time aligned to the onset of the shift, averaged according to shift direction, and the onset of the first voice F0 response was measured. Average manual reaction time was calculated. Findings indicated no significant correlation between manual responses and early voice F0 response. However, later voice F0 responses and manual reaction times were positively correlated. These results are consistent with the hypothesis that the early voice F0 response is automatically generated, and later responses are under voluntary influence. Results also suggest that the variability of later voice F0 responses may be a function of individual differences in volitional motor response abilities. [Work supported by NINDS.]
Comparing methods for measuring pitch ‘‘elbows.’’
Authors: Shosted Ryan , Del Giudice Alex , Arvaniti Amalia
Published: October 2013

Currently, there is no standard method for determining the location where an F0 curve begins its upward or downward trajectory (sometimes referred to as the pitch ‘‘elbow’’). It is generally accepted that elbows are hard to measure in a consistent way: some studies have used least-squares fitting methods, others have relied on visual judgments. This study uses a variety of data from English and Greek that exhibit different degrees of difficulty for locating the elbow. Automated results are derived from various implementations of two algorithms. The first algorithm uses linear least-squares fitting, where the intersection of two lines that best approximate the pitch contour denotes the point of the elbow. The second algorithm analyzes point-by-point changes. The results are then compared with those of human labelers. We present results from a series of statistical tests that estimate the robustness of variations on these two algorithms with respect to the performance of the human labelers. Our aim is to provide a method for measuring elbows that is robust and easy to implement and that can be used with different types of pitch contours, in order to improve accuracy of measurements. a)Also at Univeristy of California, Berkeley.
Semi-automatic labeling of pitch accents in American English
Authors: Stojanovic Diana , Sakata Yohei
Published: October 2013

This study provides a simple classification of several pitch accents that occur in American English, based on acoustic measurements of F0. Audio samples recorded by a female speaker and transcribed in the ToBI framework (Beckman, 1994) were used to develop five rules to recognize the pitch accents H*, L*, L+H*, and L*+H. Since no information about prosodic phrasing was given to the recognizer, some combinations with phrase accents were considered and contours then grouped into equivalent labels (e.g., %HL* equivalent to H*L−). Based on the rules developed, a semi−automatic process of labeling pitch accents was implemented in Praat. Half of the audio samples were used to train the labeler, the other half to test it. The accuracy level achieved was 69%. When effects of microprosody, creaky voice, or incorrect automatic pitch tracking were removed, the accuracy of classification into equivalent labels increased to 90%. Two types of applications are proposed: semi−automatic computer labeling of intonation for larger quantities of data, and a tool to help human transcribers learn American English ToBI using Praat. In addition, the simple classification is the first step towards looking into speaker variability in realization of different contours, and typology of intonational contours in different languages.
Parametric spectrogram modeling of single and concurrent speech with spline pitch contour
Authors: Le Roux Jonathan , Kameoka Hirokazu , Ono Nobutaka , Sagayama Shigeki
Published: October 2013

This paper proposes a novel general speech analysis framework consisting in a precise and parametric description of speech directly from the power spectrum, resulting in a new efficient pitch estimation method for both single and multiple speaker situations. The speech spectrum is modeled as a sequence of spectral clusters governed by a common pitch contour expressed as a spline curve. These clusters are isolated by an unsupervised 2-D time-frequency categorization of the energy density, and their common pitch contour is estimated simultaneously. A smooth pitch contour can thus be extracted on the whole utterance, linking together its voiced parts, while this is difficult or impossible for frame-by-frame algorithms. The proposed algorithm is compared to several existing methods on a database of single speaker speech, with very good results that place it among the most accurate ones. Moreover, its very high accuracy is shown on the estimation of multi-pitch contours of co-channel concurrent speech.
Peak alignment in accented Tolowa syllables
Authors: Doty Christopher
Published: October 2013

Tolowa (Athabaskan, Pacific Coast Group) has only three remaining fluent speakers near Crescent City, CA. Tolowa has prominent pitch contours that have been described both as an interaction of stress and vowel length and as lexically specified pitch accent. The present study examined the phonetic realization of these pitch contours. Fundamental frequency (F0) at its highest peak during the rhyme of accented syllables was measured, as was relative duration into the rhyme at which the peak occurred. Preliminary results indicated that a high pitch peak occurred approximately 20%–30% of the way into the rhyme of the syllable. In the case of long vowels in accented syllables, this led to a prominent peak which fell sharply during the second half of the rhyme. A similar peak and fall was seen in accented syllables closed by a voiced sonorant. In the case of accented syllables with short vowels closed by a voiceless consonant, the accent was realized as a rise in pitch leading to the final consonant. These results indicate that the phonetic target is a high peak 20%–30% into the rhyme; the target seems to not include the fall seen in rhymes with long vowels or those closed by voiced sonorants.
Bengali intonational phonology
Authors: Khan Sameer ud Dowla
Published: October 2013

Previous studies of Bengali intonation are primarily concerned with the mapping between syntax and intonation, the existence of accentual and phonological phrases, optionality in phrasing, and realization of focus. While these studies have been influential, they shy away from a full description of Bengali intonation, drawing from a small data set produced by a handful of speakers. At present, there is no comprehensive analysis of Bengali intonation that uses data collected from a wide range of speakers. The current study adopts the framework of intonational phonology (Pierrehumbert, 1980; Ladd, 1996) to develop such an analysis based on a large set of data from approximately 25 Bengali speakers. A pilot study measuring pitch and segment durations in 155 sentences suggests the existence of three pitch accent types (low, high, rising) and three levels of prosodic units whose right edges are marked by a boundary tone (intonation, intermediate, accentual). This suggests that Bengali differs from most other languages (Jun, 2005) in having both (1) contrastive pitch accents and (2) a small prosodic unit that is the domain of the pitch accent (i.e., the accentual phrase). Further analyses will illustrate the phonetic realizations of pitch accents and boundary tones in the language.
The Sediment Acoustics Experiment in 2004 (SAX04)
Authors: Thorsos Eric I. , Williams Kevin L. , Tang Dajun , Kargl Steven G. , Jackson Darrell R. , Hefner Brian T.
Published: October 2013

A major sediment acoustics experiment (SAX04) was conducted near the coast of northwestern Florida, USA during September–November 2004. In addition to our laboratory, a number of other institutions participated, principally from the USA and Canada. SAX04 addressed sound penetration into, propagation within, and scattering from the shallow-water seafloor, as well as scattering from proud and buried targets. The sandy sediment at the experiment site has a critical angle of nearly 30 deg, convenient for study of acoustic penetration into sediments at grazing angles below the critical angle. A shallow-water depth of about 17 m allowed divers to be utilized in many aspects of the experimental work. In particular, divers deployed a 30-m rail system on the bottom for synthetic aperture sonar and other acoustic measurements. SAX99, conducted at a site nearby, showed the importance of scattering from ripples on high-frequency acoustic penetration at subcritical grazing angles. In part because of these findings, a new research initiative on sediment ripple formation, evolution, and decay was begun by ONR, and investigators from this program carried out studies at the SAX04 site. An overview will be given of the SAX04 measurement program. [Work supported by ONR.]
Progress in electroacoustic transducer research
Authors: Sessler Gerhard M.
Published: October 2013

Manfred Schroeder always had a vivid interest in the field of electroacoustic transducers. During his time as Director of Acoustics Research at Bell Laboratories, work on electret transducers was started by Jim West and the author in 1962 and the activities were extended over the years to electret materials, directional microphones, and microphone signal processing. Schroeder himself made some interesting contributions to this field, such as the design of directional microphones based on gradients of various orders with toroidal and unidirectional directivity patterns. Some of these devices were implemented with electret transducers. Work on directional microphones at Bell Labs continued as the author went to the Darmstadt University of Technology. There, studies on silicon transducers were initiated, with the first silicon condenser microphone described in 1983. Recently, a completely new and promising variety of piezoelectric transducers was implemented, consisting of charged cellular polymers. This is a new modification of the electret transducer principle developed in the 1960s at Bell Laboratories.
Application of digital signal processing to architectural acoustics in the 1960s
Authors: West James E.
Published: October 2013

Digital signal processing techniques in architectural acoustics were first used to investigate the acoustical properties of Philharmonic Hall at Lincoln Center for the Performing Arts in New York City in the early 1960s. The management of Lincoln Center invited the Acoustics Research Department of Bell Labs, headed by Manfred Schroeder, to assist in an evaluation of the Hall because conventional measurement methods were unable to explain its subjective performance. Computer-generated specially shaped tone bursts were played and the sound pressures at different locations in the Hall were recorded and later converted into digital form for evaluation. Special filters were programmed to evaluate reverberation times based on different portions of the decay, and energy distribution in time, space, and frequency domains. Better insights into the relationships between subjective and physical measurements were made possible utilizing the power in digital signal processing.
Are concert halls random number generators?
Authors: Polack Jean-Dominique
Published: October 2013

In 1954, Manfred Schroeder proved that sound fields in rooms are statistical in nature. Based on his subsequent work, several models of sound fields were derived, both in the frequency and the time domain, that make it possible to predict most of the properties of sound fields in rooms, including the major room-acoustical indices. One of these models, derived by the author, is based on random number generation, another field to which Manfred Schroeder contributed. This model is presented, and its predictions compared to measurements by A. C. Gade and G. W. Siebein in US concert halls (see Gade’s presentation at Sabine Centennial symposium in June 1994). Predictions are also compared with current theories of reverberation. However, the model is not able to predict the modal behavior below the Schroeder frequency yet. The solution lays in the so-called semiclassical approximation, which is briefly presented. The case of rectangular halls, where the semiclassical approach is no longer an approximation, but is exact, illustrates how to reconcile Monte Carlo approaches, ray theory, and mode distribution.
Recent advances in hearing and sound communication by fishes
Authors: Ladich Friedrich
Published: October 2013

Acoustic displays have been observed in representatives of 30 or more families of bony fishes. Thanks to Art Myrberg’s groundbreaking work, we have insights into the multitude of functions of acoustic signalling in fishes including mate choice, individual and species recognition, reduction of territory intrusions, and interception. Recent studies, many of which have arisen from Art’s work, focus on ontogenetic and seasonal changes, female vocalizations, and effects of ambient and anthropogenic noise in hearing and sound communication. In croaking gouramis (labyrinth fishes), for example, ontogenetic development of acoustic communication depends on changes in sound parameters, increases in sound levels, and auditory sensitivities. The importance of seasonal changes in hearing was recently uncovered in toadfish and cyprinids. Generally male fish display acoustically to attract females, but the opposite may occur. Only female croaking gouramis vocalize during mating. Ecoacoustical investigations reveal that hearing specialists (cyprinids) are well adapted to the low ambient noise levels of standing freshwaters. They are heavily masked in flowing waters, unlike generalists, which are merely affected by ambient noise. Gaussian and ship noise diminishes a fish’s ability to detect sounds and resolve temporal patterns, indicating that human-made noise affects acoustic orientation and communication in fishes. [Work supported by FWF.]
Directional hearing in sharks and other fishes
Authors: Hawkins Anthony
Published: October 2013

Art Myrberg and his co-workers were among the first biologists to obtain clear evidence that predatory sharks are able to locate sound sources at long distances. Previous experiments had shown that elasmobranches were relatively insensitive to sounds, and it had been suggested that fish were incapable of determining the direction of a sound source in the far field. It was subsequently shown that fish could discriminate between sounds from spatially separated sources in the horizontal and median vertical planes. They could even distinguish between identical sound sources at differing distances. It has been suggested that fish determine direction using particle motion detectors, the otolith organs of the inner ear. An array of vector detectors is capable of detecting the axis of propagation, but as they are inherently bidirectional there remains a problem in detecting the actual direction of the source. This paper considers the proposal that the ambiguities are resolved by phase comparison between the vector detectors and other detectors responding to the sound pressure incident upon the gas-filled swimbladde.
Sound production in two loricariid catfishes
Authors: Webb Amanda L. , Smith Michael E.
Published: October 2013

Many families of catfishes produce sounds via pectoral spine stridulation and/or swim bladder compression using sonic muscles linked to the swimbladder. Sound production capabilities in the catfish family Loricariidae has not yet been examined. We recorded sounds produced by two species of loricariid catfish, Otocinclus affinis and Pterygoplichthys gibbiceps. Both species produced short, broadband clicks via pectoral spine stridulation. Mean fundamental and dominant frequencies for O. affinis and P. gibbiceps were approximately 4000 and 8000, and 600 and 1200 Hz, respectively. Durations of sound pulses were generally shorter in O. affinis (2–12 ms) compared to P. gibbiceps (20–100 ms). Scanning electron microscopy was used to examine the dorsal process of the base of the pectoral spines of each species. Sound is produced as the ridges of the pectoral spine base slides past the channel of the pectoral girdle. Distances between dorsal process ridges of O. affinis and P. gibbiceps were approximately 50 and 160 microns, respectively, with the ratio of this distance to the fish total length being comparable between species. Relationships between spine interridge distance, pulse duration, and spectrum of the sounds produced will be discussed. [We thank John Andersland for SEM assistance.]
Modeling of the backscattering by swimbladder-bearing fish
Authors: Chu Dezhang , Stanton Timothy K. , Jech J. Michael , Reeder D. Benjamin
Published: October 2013

A composite scattering model has been developed to describe the backscattering by swimbladder-bearing fish. This model includes the influence of elongation of the swim-bladder not only on the resonance frequency, as do most of the existing scattering models, but also on the quality factor Q and the overall scattering level. In addition, within the region covering the transition from resonance scattering to geometric scattering, the effect of asymmetric cross section of the swimbladder has also been included to represent a more realistic shape of fish swimbladder. The model was compared with other scattering models, such as Kirchhoff ray mode (KRM) and Fourier matching method (FMM). Model predictions were then compared with field data collected with a new broadband towed system. For a single-species Atlantic herring school (Clupea harengus) with a measured length distribution, the predicted resonance scattering including resonance peak location and overall level matched the broadband acoustic data reasonably well. Some modeling issues will also be discussed.