bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinearities and self-organization in the sound production of the Rhodes piano
Authors: Muenster Malte , Pfeifle Florian , Weinrich Till , Keil Martin
Published: October 2014

Over the last five decades the Rhodes piano became a common keyboard instrument. It is played in such diverse musical genres as Jazz, Funk, Fusion, or Pop. The sound processing of the Rhodes has not been studied in detail beforeIts sound is produced by a mechanical driven tuning fork like system causing a change in the magnetic flux of an electromagnetic pick up system. The mechanical part of the tone production consists of a small diameter tine made of stiff spring steel, the tine, and a tone bar made of brass, which is strongly coupled to the former and acts as a resonator. The system is an example for strong generator-resonator coupling. The tine acts as a generator forcing the tonebar to vibrate with its fundamental frequency. Despite of extremely different and much lower eigenfrequencies the tonebar is enslaved by the tine. The tine is of lower spatial dimension and less damped and acts nearly linear. The geometry of the tonebar is much more complex and therefore of higher dimension and damped stronger. The vibration of these two parts are perfectly in-phase or anti-phase pointing to a quasi-synchronization behavior. Moreover, the tonebar is responsible for the timbre of the initial transient. It adds the glockenspiel sound to the transient and extends the sustain. The sound production is discussed as synergetic, self-organizing system, leading to a very precise harmonic overtone structure and characteristic initial transients enhancing the variety of musical performance.
Evaluation of level-dependent performance of in-ear hearing protection devices using an enclosed sound source
Authors: Argo Theodore F. , Meegan G. Douglas
Published: October 2014

Hearing protection devices are increasingly designed with the capability to protect against impulsive sound. Current methods used to test protection from impulsive noise, such as blasts and gunshots, suffer from various drawbacks and complex, manual experimental procedures. For example, the use of a shock tube to emulate blast waves typically produces a blast wind of a much higher magnitude than that generated by an explosive, a specific but important inconsistency between the test conditions and final application. Shock tube test procedures are also very inflexible and provide only minimal insight into the function and performance of advanced electronic hearing protection devices that may have relatively complex response as a function of amplitude and frequency content. To address the issue of measuring the amplitude-dependent attenuation provided by a hearing protection device, a method using a compression driver attached to an enclosed waveguide was developed. The hearing protection device is placed at the end of the waveguide and the response to exposure to impulsive and frequency-dependent signals at calibrated levels is measured. Comparisons to shock tube and standard frequency response measurements will be discussed.
Exploration of flat hearing protector attenuation and sound detection in noise
Authors: Giguere Christian , Berger Elliott H.
Published: October 2014

Flat-response devices are a class of hearing protectors with nearly uniform attenuation across frequency. These devices can protect the individual wearer while maintaining the spectral balance of the surrounding sounds. This is typically achieved by reducing the muffling effect of conventional hearing protectors which provide larger attenuation at higher than lower frequencies, especially with earmuffs. Flat hearing protectors are often recommended when good speech communication or sound perception is essential, especially for wearers with high-frequency hearing loss, to maintain audibility at all frequencies. However, while flat-response devices are described in some acoustical standards, the tolerance limits for the definition of flatness are largely unspecified and relatively little is known on the exact conditions when such devices can be beneficial. The purpose of this study is to gain insight into the interaction between the spectrum of the noise, the shape of the attenuation-frequency response, and the hearing loss configuration on detection thresholds using a psychoacoustic model of sound detection in noise.
Electronic sound transmission hearing protectors and horizontal localization: Training/adaptation effects
Authors: Casali John , Robinette Martin
Published: October 2014

Auditory situation awareness is known to be affected by some hearing protectors, even advanced electronic devices. A horizontal localization task was employed to determine how use/training with electronic sound transmission hearing protectors affected auditory localization ability, as compared to open-ear. Twelve normal-hearing participants performed baseline localization testing in a hemi-anechoic field in three listening conditions: open-ear, in-the-ear (ITE) device (Etymotic EB-15), and over-the-ear (OTE) device (Peltor ComTac II). Participants then wore either the ITE or OTE protector for 12, almost daily, one-hour training sessions. Post-training, participants again underwent localization testing with all three conditions. A computerized custom software-hardware interface presented localization sounds and collected accuracy and timing measures. ANOVA and post hoc statistical tests revealed that pre-training localization performance with either the ITE or OTE protector was significantly worse (p<0.05) than open-ear performance. After training with any given listening condition, performance in that condition improved, in part from a practice effect. However, post-training localization showed near equal performance between the open-ear and the protector on which training occurred. Auditory learning, manifested as significant localization accuracy improvement, occurred for the training device, but not for the non-training device, i.e., no crossover benefit from the training device to the non-training device occurred.
Measuring effective detection and localization performance of hearing protection devices
Authors: McKinley Richard L. , Thompson Eric R. , Simpson Brian D.
Published: October 2014

Awareness of the surrounding acoustic environment is essential to the safety of persons. However, the use of hearing protection devices can degrade the ability to detect and localize sounds, particularly quiet sounds. There are ANSI/ASA standards describing methods for measuring attenuation, insertion loss, and speech intelligibility in noise for hearing protection devices, but currently there are no standard methods to measure the effects of hearing protection devices on localization and/or detection performance. A method for measuring the impact of hearing protectors on effective detection and localization performance has been developed at AFRL. This method measures the response time in an aurally aided visual search task where the presentation levels are varied. The performance with several level-dependent hearing protection devices will be presented.
Noise level from burning articles on the fireground
Authors: Abbasi Mustafa Z. , Wilson Preston S. , Ezekoye Ofodike A.
Published: October 2014

Firefighters encounter an extremely difficult environment due to the presence of heat, smoke, falling debris etc. If one of them needs rescue, an audible alarm is used to alert others of their location. This alarm, known as the Personal Alert Safety System (PASS) alarm, has been part of firefighter gear since the early 1980s. The PASS has been enormously successful, but a review of The National Institute for Occupational Safety and Health (NIOSH) firefighter fatality report suggests that there are instances when the alarm is not heard or not localized. In the past, we have studied fireground noise from various pieces of gear such as chainsaws and fans, etc., to understand the soundscape present during a firefighting operation. However, firefighters, and other interested parties have raised the issue of noise caused by the fire itself. The literature shows that buoyancy-controlled, non-premixed flames aerodynamically oscillate in the 10–16 Hz range, depending on the diameter of the fuel base. Surprisingly, few acoustic measurements have been made even for these relatively clean fire conditions. However, experience suggests burning items do create sounds. Most likely these sound are from the decomposition of the material as it undergoes pyrolysis (turns in gaseous fuel and char). This paper will present noise measurements from various burning articles as well as characterization of the fire to understand this noise source.
Bacterial attachment and insertion loss of earplugs used longtime in the noisy workplace
Authors: Inoue Jinro , Nakamura Aya , Tanizawa Yumi , Horie Seichi
Published: October 2014

In the real noisy workplace, workers often use earplugs for a longtime. We assessed the condition of bacterial attachment and the insertion loss of 197 pairs of earplugs collected from 6 companies. The total viable counts and the presence of Staphylococcus aureus were examined by 3M Petrifilm. The insertion losses were evaluated by GRAS 45CB Acoustic Test Fixture. We detected greater number of viable counts in the foam earplugs than in the premolded earplugs. Staphylococcus aureus was detected in 10 foam earplugs (5.1%). The deterioration of insertion loss was found only in the deformed earplugs. The condition of work environment such as presence of dust or use of oily liquid might cause the deterioration. Both the condition of bacterial attachment and the insertion loss were not correlated with the duration of use. We observed no correlation between the condition of bacterial attachment and the insertion loss of earplugs and neither of them was related to the duration of long-term use of the earplugs.
Low-dimensional acoustic structures in the near-field of clustered rocket nozzles
Authors: Canchero Andres , Tinney Charles E. , Murray Nathan E. , Ruf Joseph H.
Published: October 2014

The plume and acoustic field produced by a cluster of two and four rocket nozzles is visualized by way of retroreflective shadowgraphy. Both steady state and transient operations of the nozzles (start-up and shut-down) were conducted in the fully-anechoic chamber and open jet facility of The University of Texas at Austin. The laboratory scale rocket nozzles comprise thrust-optimized parabolic (TOP) contours, which during start-up, experience free shock separated flow, restricted shock separated flow, and an “end-effects regime” prior to flowing full. Shadowgraphy images are first compared with several RANS simulations during steady operations. A proper orthogonal decomposition (POD) of various regions in the shadowgraphy images is then performed to elucidate the prominent features residing in the supersonic annular flow region, the acoustic near field and the interaction zone that resides between the nozzle plumes. Synchronized surveys of the acoustic loads produced in close vicinity to the rocket clusters are compared to the low-order shadowgraphy images in order to identify the various mechanisms within the near-field that are responsible for generating sound.
Detached-Eddy simulations of rocket plume noise at lift-off
Authors: Lyrintzis A. , Golubev V. , Kurbatski K. , Osman E. , Mankbadi Reda
Published: October 2014

The three-dimensional turbulent flow and acoustic field of a supersonic jet impinging on a solid plate at different inclination angles is studied computationally using the general-purpose CFD code ANSYS Fluent. A pressure-based coupled solver formulation with the second-order weighted central-upwind spatial discretization is applied. Hot jet thermal condition is considered. Acoustic radiation of impingement tones is simulated using a transient time-domain formulation. The effects of turbulence in steady state are modeled by the SST k- turbulence model. The Wall-Modeled Large-Eddy Simulation (WMLES) model is applied to compute transient solutions. The near-wall mesh on the impingement plate is fine enough to resolve the viscosity-affected near-wall region all the way to the laminar sublayer. Inclination angle of the impingement plate is parameterized in the model for automatic re-generation of the mesh and results. The transient solution reproduces the mechanism of impingement tone generation by the interaction of large-scale vortical structures with the impingement plate. The acoustic near field is directly resolved by the Computational Aeroacoustics (CAA) to accurately propagate impingement tone waves to near-field microphone locations. Results show the effect of the inclination angle on sound level pressure spectra and overall sound pressure level directivities.
Scaling metrics for predicting rocket noise
Authors: Mack Gregory , Tinney Charles E. , Ruf Joseph
Published: October 2014

Several years of research at The University of Texas at Austin concerning the sound field produced by large area-ratio rocket nozzles is presented [Baars et al., AIAA J. 50(1), (2012); Baars and Tinney, Exp. Fluids, 54 (1468), (2013); Donald et al., AIAA J. 52(7), (2013)]. The focus of these studies is on developing an in-depth understanding of the various acoustic mechanisms that form during start-up of rocket engines and how they may be rendered less efficient in the generation of sound. The test articles comprise geometrically scaled replicas of large area ratio nozzles and are tested in a fully anechoic chamber under various operating conditions. A framework for scaling laboratory-scale nozzles is presented by combining established methods with new methodologies [Mayes, NASA TN D-21 (1959); Gust, NASA TN-D-1999 (1964); Eldred, NASA SP-8072 (1972); Sutherland AIAA Paper 1993–4383 (1993); Varnier, AIAA J. 39:10 (2001); James et al. Proc. Acoust. Soc. Amer. 18(3aNS), (2012)]. In particular, both hot and cold flow tests are reported which comprise single, three and four nozzle clusters. An effort to correct for geometric scaling is also presented.
Influence of source level, peak frequency, and atmospheric absorption on nonlinear propagation of rocket noise
Authors: Pearson Michael F. , Gee Kent L. , Neilsen Tracianne B. , Reichman Brent O. , James Michael M. , Salton Alexandira R.
Published: October 2014

Nonlinear propagation effects in rocket noise have been previously shown to be significant [M. B. Muhlestein et al. Proc. Mtgs. Acoust. (2013)]. This paper explores the influence of source level, peak frequency, and ambient atmospheric conditions on predictions of nonlinear propagation. An acoustic pressure waveform measured during a full-scale solid rocket motor firing is numerically propagated via generalized Burgers equation model for atmospheric conditions representative of plausible spaceport locations. Cases are explored where the overall sound pressure level and peak frequency has been scaled to model engines of different scale or thrust. The predicted power spectral densities and overall sound pressure levels, both flat and A-weighted, are compared for nonlinear and linear propagation for distances up to 30 km. The differences in overall level suggest that further research to appropriately include nonlinear effects in launch vehicle noise models is worthwhile.
Sharing experiments for home and classroom demonstrations
Authors: Rossing Thomas D.
Published: October 2014

In the third edition of The Science of Sound, we included a list of “Experiments for Home, Laboratory, and Classroom Demonstrations” at the end of each chapter. Some of the demonstrations are done by the instructor in class, some are done by students for extra credit, some are intended to be done at home. We describe a representative number of these, many of which can be done without special equipment.
A qualitative demonstration of the behavior of the human cochlea
Authors: Morrison Andrew C.
Published: October 2014

Demonstrations of the motion of the basilar membrane in the human cochlea designed by Keolian [J. Acoust. Soc. Am. 101, 1199-1201 (1997)], Tomlinson et. al. [J. Acoust. Soc. Am. 121, 3115 (2007)], and others provide a way for students in a class to visualize the behavior of the basilar membrane and explore the physical mechanisms leading to many auditory phenomena. The designs of Keolian and Tomlinson are hydrodynamic. A non-hydrodynamic apparatus has been designed that can be constructed with commonly available laboratory supplies and items readily available at local hardware stores. The apparatus is easily set up for demonstration purposes and is compact for storing between uses. The merits and limitations of this design will be presented.
Nonlinear demonstrations in acoustics
Authors: Korman Murray S.
Published: October 2014

The world is nonlinear, and in presenting demonstrations in acoustics, one often has to consider the effects of nonlinearity. In this presentation the nonlinear effects are made to be very pronounced. The nonlinear effects of standing waves on a lightly stretched string (which is also very elastic) lead to wave shape distortion, mode jumping and hysteresis effects in the resonant behavior of a tuning curve near a resonance. The effects of hyperelasticity in a rubber string are discussed. A two dimensional system like a vibrating rectangular or circular drum-head are well known. The nonlinear effects of standing waves on a lightly stretched hyperelastic membrane make an interesting and challenging study. Here, tuning curve behavior demonstrates that there is softening of the system for slightly increasing vibration amplitudes followed by stiffening of the system at larger vibration amplitudes. The hysteretic behavior of the tuning curve for sweeping from lower to higher frequencies and then from higher to lower frequencies (for the same drive amplitude) is demonstrated. Lastly, the nonlinear effects of a column of soil or fine granular material loading a thin elastic circular clamped plate are demonstrated near resonance. Here again, the nonlinear highly asymmetric tuning curve behavior is demonstrated.
A multisource-type representation statistically optimized near-field acoustical holography method
Authors: Wall Alan T. , Gee Kent L. , Neilsen Tracianne B.
Published: October 2014

A reduced-order approach to near-field acoustical holography (NAH) that accounts for sound fields generated by multiple spatially separated sources of different types is presented. In this method, an equivalent wave model (EWM) of a given field is formulated based on rudimentary knowledge of source types and locations. The statistically optimized near-field acoustical holography (SONAH) algorithm is utilized to perform the NAH projection after the formulation of the multisource EWM. The combined process is called multisource-type representation SONAH (MSTR SONAH). This method is used to reconstruct simulated sound fields generated by combinations of multiple source types. It is shown that MSTR SONAH can successfully reconstruct the near field pressures in multisource environments where other NAH methods result in large errors. The MSTR SONAH technique can be extended to general sound fields where the shapes and locations of sources and scattering bodies are known.
Bayesian regularization applied to real-time near-field acoustic holography
Authors: Le Magueresse Thibaut , Thomas Jean-Hugh , Antoni Jérôme , Paillasseur Sébasien
Published: October 2014

Real-Time Near-field Acoustic Holography is used to recover non stationary acoustic sound sources using a planar microphone array. In the direct way, describing propagation requires the convolution of the spatial spectrum of the source under study with a known impulse response. When the convolution operator is replaced with a matrix product, the propagation operator is re-written in a Toeplitz matrix form. Solving the inverse problem is based on a Singular value decomposition of this propagator and Tikhonov regularization is used to stabilize the solution. The purpose here is to study the regularization process. The formulation of this problem in the Tikhonov sense estimates the solution from the knowledge of the propagation model, the measurements and the regularization parameter. This parameter is calculated by making a compromise between the fidelity to the real measured data and the fidelity to available a priori information. A new regularization parameter is introduced based on a Bayesian approach to maximize the information taken into account. Comparisons of the results are proposed, using the L-Curve and the generalized cross validation. The superiority of the Bayesian parameter is observed for the reconstruction of a non stationary experimental source using real-time near-field acoustic holography.
Acoustic building infiltration measurement system
Authors: Muehleisen Ralph T. , Tatara Eric , Raman Ganesh , Chelliah Kanthasamy
Published: October 2014

Building infiltration is a significant portion of the heating and cooling load of buildings and accounts for nearly 4% of the total energy use in the United States. Current measurement methods for locating and quantifying infiltration in commercial buildings to apply remediation are very limited. In this talk, the development of a new measurement system, the Acoustic Building Infiltration Measurement System (ABIMS) is presented. ABIMS uses Nearfield Acoustic Holography (NAH) to measure the sound field transmitted through a section of the building envelope. These data are used to locate and quantify the infiltration sites of a building envelope section. The basic theory of ABIMS operation and results from computer simulations are presented.
Interactions among lexical and discourse characteristics in vowel production
Authors: Burdin Rachel S. , Turnbull Rory , Clopper Cynthia G.
Published: October 2014

Various factors are known to affect vowel production, including word frequency, neighborhood density, contextual predictability, mention in the discourse, and audience. This study explores interactions between all five of these factors on vowel duration and dispersion. Participants read paragraphs that contained target words which varied in predictability, frequency, and density. Each target word appeared twice in the paragraph. Participants read each paragraph twice: as if they were talking to a friend (“plain speech”) and as if they were talking to a hearing-impaired or non-native interlocutor (“clear speech”). Measures of vowel duration and dispersion were obtained. Results from the plain speech passages revealed that second mention and more predictable words were shorter than first mention and less predictable words, and that vowels in second mention and low density words were less peripheral than in first mention and high density words. Interactions between frequency and mention, and density and mention, were also observed, with second mention reduction only occurring in low density and low frequency words. We expect to observe additional effects of speech style, with clear speech vowels being longer and more disperse than plain speech vowels, and that these effects will interact with frequency, density, predictability, and mention.
Phonetic correlates of phonological quantity of Yakut
Authors: Vasilyeva Lena , Järvikivi Juhani , Arnhold Anja
Published: October 2014

We investigated vowel quantity in Yakut (Sakha), a Turkic language spoken in Siberia by over 400,000 speakers in the Republic of Sakha (Yakutia) in the Russian Federation. Yakut is a quantity language; all vowel and consonant phonemes have short and long contrastive counterparts. The study aims at revealing acoustic characteristics of the binary quantity distinction in vowels. We used two sets of data: (1) A female native Yakut speaker read a 200-word list containing disyllabic nouns and verbs with four different combinations of vowel length in the two syllables (short–short, short–long, long–short, and long–long) and a list of 50 minimal pairs differing only in vowel length; (2) Spontaneous speech data from 9 female native Yakut speakers (aged 19–77), 200 words with short vowels and 200 words with long vowels, were extracted for analysis. Acoustic measurements of the short and long vowels’ f0-values, duration and intensity were done. Mixed-effects models showed a significant durational difference between long and short vowels for both data sets. However, the preliminary results indicated that, unlike in quantity languages like Finnish and Estonian, there was no consistent effect of f0 as the phonetic correlate in Yakut vowel quantity distinction.
Acoustic and perceptual characteristics of vowels produced by self-identified gay and heterosexual male speakers
Authors: Johnson Keith , Tracy Erik C.
Published: October 2014

Prior research (Tracy & Satariano, 2011) investigated the perceptual characteristics of gay and heterosexual male speech; it was discovered that listeners primarily relied on vowels to identify sexual orientation. Using single-word utterances produced by those same speakers, the current study examined both the acoustic characteristics of vowels, such as pitch, duration, and the size of the vowel space, and how these characteristics relate to the perceived sexual orientation of the speaker. We found a correlation between pitch and perceived sexual identity for vowels produced by heterosexual speakers—higher f0 was associated with perceptual “gayness.” We did not find this correlation for gay speakers. Vowel duration did not reliably distinguish gay and heterosexual speakers, but speakers who produced longer vowels were perceived as gay and speakers who produced shorter vowels were perceived as heterosexual. The size of the vowel space did not reliably differ between gay and heterosexual speakers. However, speakers who produced a larger vowel space were perceived as more gay-sounding than speakers who produced a smaller vowel space. The results suggest that listeners rely on these acoustic characteristics when asked to determine a male speaker’s sexual orientation, but that the stereotypes that they seem to rely upon are inaccurate.
Cue integration in the perception of fricative-vowel coarticulation in Korean
Authors: Lee Goun , Jongman Allard
Published: October 2014

Korean distinguishes two fricatives—fortis [s’] and non-fortis [s]. Perception of this distinction was tested in two different vowel contexts, with three types of stimuli (consonant-only, vowel-only, or consonant-vowel sequences) (Experiment 1). The relative contribution of consonantal and vocalic cues was also examined with cross-spliced stimuli (Experiment 2). Listeners’ weighting of 7 perceptual cues—spectral mean (initial 60%, final 40%), vowel duration, H1-H2* (onset, mid), and cepstral peak prominence (onset, mid)—was examined. The data demonstrate that identification performance was heavily influenced by vowel context and listener performance was more accurate in the /a/ vowel context than in the /i/ vowel context. In addition, the type of stimulus presented changed the perceptual cue weighting. When presented with conflicting cues, listener decisions were driven by the vocalic cues in the /a/ vowel context. These results suggest that perceptual cues associated with breathy phonation are the primary cues for fricative identification in Korean.
Voicing, devoicing, and noise measures in Shanghainese voiced and voiceless glottal fricatives
Authors: Koenig Laura L. , Shi Lu-Feng
Published: October 2014

Shanghainese has a rather rare voicing distinction between the glottal fricatives /h/ and /ɦ/. We evaluate the acoustic characteristics of this contrast in ten male and ten female speakers of urban Shanghainese dialect. Participants produced 20 CV words with a mid/low central vowel in a short carrier phrase. All legal consonant-tone combinations were used: /h/ preceded high, low, and short tones whereas /ɦ/ preceded low and short tones. Preliminary analyses suggested that the traditional “voiced” and “voiceless” labels for these sounds are not always phonetically accurate; hence we measure the duration of any voicing break relative to the entire phrase, as well as the harmonics-to-noise ratio (HNR) over the time. We expect longer relative voiceless durations and lower HNR measures for /h/ compared to /ɦ/. A question of interest is whether any gender differences emerge. A previous study on American English [Koenig, 2000, JSLHR 43, 1211–1228] found that men phonated through their productions of /h/ more often than women, and interpreted that finding in terms of male-female differences in vocal fold characteristics. A language that contrasts /h/ and /ɦ/ might minimize any such gender variation. Alternatively, the contrast might be realized in slightly different ways in men and women.
Incomplete neutralization of sibilant consonants in Penang Mandarin: A palatographic case study
Authors: Huang Ting , Chang Yueh-chin , Hsieh Feng-fan
Published: October 2014

It has been anecdotally observed that the three-way contrasts in Standard Chinese are reduced to two-way contrasts in Penang Mandarin (PM). PM is a variety of Mandarin Chinese spoken in Penang of Malaysia, which is influenced by Penang Hokkien. This work shows that the alleged neutralization of contrasts is incomplete (10 consonants x 3 vowel contexts x 5 speakers). More specifically, alveopalatal [ɕ] may range from postalveolar zone (73.33%) to alveolar zone (26.67%), and so does retroflex [ʂ] (46.67% vs. 46.67%). [s] and [n] are apical (or [ + anterior]) coronals. The goal of this study is three-fold: (i) to describe the places of articulation of PM coronals and the patterns of ongoing sound changes, (ii) to show the neutralization of place contrasts is incomplete whereby constriction length remains distinct for these sibilant sounds, and (iii) to demonstrate different coarticulatory patterns of consonants in variant vowel contexts. The intricate division of coronal consonants does not warrant a precise constriction location on the upper palate. This PM data lend support to Ladefoged and Wu’s (1984) observation that it is not easy to pin down a clear-cut boundary between dental and alveolar stops, and between alveolar and palatoalveolar fricatives.
Final voicing and devoicing in American English
Authors: Dmitrieva Olga
Published: October 2014

English is typically described as a language in which voicing contrast is not neutralized in word-final position. However, a tendency towards devoicing (at least partial) of final voiced obstruents in English has been reported by the previous studies (e.g., Docherty (1992) and references therein). In the present study, we examine a number of acoustic correlates of obstruent voicing and the robustness with which each one is able to differentiate between voiced and voiceless obstruents in the word-final position in the speech recorded by twenty native speakers of the Mid-Western dialect of American English. The examined acoustic properties include preceding vowel duration, closure or frication duration, duration of the release portion, and duration of voicing during the obstruent closure, frication, and release. Initial results indicate that final voiced obstruents are significantly different from the voiceless ones in terms of preceding vowel duration and closure/frication duration. However, release duration for stops does not appear to correlate with voicing in an equally reliable fashion. A well-pronounced difference in terms of closure voicing between voiced and voiceless final stops is significantly reduced in fricative consonants, which indicates a tendency towards neutralization of this particular correlate of voicing in the word-final fricatives of American English.
Quantifying surface phonetic variation using acoustic landmarks as feature cues
Authors: Choi Jeung-Yoon , Shattuck-Hufnagel Stefanie
Published: October 2014

Acoustic landmarks, which are abrupt spectral changes associated with certain feature sequences in spoken utterances, are highly informative and have been proposed as the initial analysis stage in human speech perception, and for automatic speech recognition (Stevens, JASA 111(4), 2002, 1872–1891). These feature cues and their parameter values also provide an effective tool for quantifying systematic context-governed surface phonetic variation (Shattuck-Hufnagel and Veilleux, ICPhS XVI, 2007, 925–928). However, few studies have provided landmark-based information about the full range of variation in continuous communicative speech. The current study examines landmark modification patterns in a corpus of maptask-elicited speech, hand annotated for whether the landmarks were realized as predicted from the word forms or modified in context. Preliminary analyses of a single conversation (400 s, one speaker) show that the majority of landmarks (about 84%) exhibited the canonical form predicted from their lexical specifications, and that modifications were distributed systematically across segment types. For example, 90% of vowel landmarks (at amplitude/F1 peaks) were realized as predicted, but only 70% of the closures for non-strident fricatives /v/ and /dh/, and 40–50% of /t/ closures and releases. Further quantification of landmark modification patterns will provide useful information about the processing of surface phonetic variation.
An acoustic comparison of dental and retroflex sibilants in Chinese Mandarin and Taiwan Mandarin
Authors: Yan Hanbo , Jongman Allard
Published: October 2014

Mandarin has both dental and retroflex sibilants. While the Mandarin varieties spoken in China and Taiwan are often considered the same, native speakers of Mandarin can tell the difference between the two. One obvious difference is that between the retroflex ([ʂ], [tʂ], [tʂh]) and dental sibilants ([s], [ts], [tsh]). This study investigates the acoustic properties of the sibilants of Chinese Mandarin and Taiwan Mandarin. Eight native speakers each of Chinese and Taiwan Mandarin produced the six target sibilants in word-initial position. A number of acoustic parameters, including spectral moments and duration, were analyzed to address two research questions: (a) which parameters distinguish the dental and retroflex in each type of Mandarin; (b) is there a difference between Chinese and Taiwan Mandarin? Results show that retroflex sibilants have a lower M1 and M2, and a higher M3 than dental sibilants in each language. Moreover, Chinese Mandarin has significantly larger M1, M2, and M3 differences than Taiwan Mandarin. This pattern suggests that, in contrast to Chinese Mandarin, Taiwan Mandarin is merging the retroflex sibilants in a dental direction.
Statistical relationships between phonological categories and acoustic-phonetic properties of Korean consonants
Authors: Silbert Noah H. , Park Hanyong
Published: October 2014

The mapping between segmental contrasts and acoustic-phonetic properties is complex and many-to-many. Contrasts are often cued by a multiple acoustic-phonetic properties, and acoustic-phonetic properties typically provide information about multiple contrasts. Following the approach of de Jong et al. (2011, JASA 129, 2455), we analyze multiple native speakers’ repeated productions of Korean obstruents using a hierarchical multivariate statistical model of the relationship between multidimensional acoustics and phonological categories. Specifically, we model the mapping between categories and multidimensional acoustic measurements from multiple repetitions of 14 Korean obstruent consonants produced by 20 native speakers (10 male, 10 female) in onset position in monosyllables. The statistical model allows us to analyze distinct within- and between-speaker sources of variability in consonant production, and model comparisons allow us to assess the utility of complexity in the assumed underlying phonological category system. In addition, by using the same set of acoustic measurements for the current project’s Korean consonants and the English consonants analyzed by de Jong et al., we can model the within- and between-language acoustic similarity of phonological categories, providing a quantitative basis for predictions about cross-language phonetic perception.
Corpus testing a fricative discriminator: Or, just how invariant is this invariant?
Authors: Roberts Philip J. , Reetz Henning , Lahiri Aditi
Published: October 2014

Acoustic cues to the distinction between sibilant fricatives are claimed to be invariant across languages. Evers et al. (1998) present a method for distinguishing automatically between [s] and [ʃ], using the slope of regression lines over separate frequency ranges within a DFT spectrum. They report accuracy rates in excess of 90% for fricatives extracted from recordings of minimal pairs in English, Dutch and Bengali. These findings are broadly replicated by Maniwa et al. (2009), using VCV tokens recorded in the lab. We tested the algorithm from Evers et al. (1998) against tokens of fricatives extracted from the TIMIT corpus of American English read speech, and the Kiel corpora of German. We were able to achieve similar accuracy rates to those reported in previous studies, with the following caveats: (1) the measure relies on being able to perform a DFT for frequencies from 0 to 8 kHz, so that a minimum sampling rate of 16 kHz is necessary for it to be effective, and (2) although the measure draws a similarly clear distinction between [s] and [ʃ] to those found in previous studies, the threshold value between the two sounds is sensitive to the dynamic range of the input signal.
Discriminant variables for plosive- and fricative-type single and geminate stops in Japanese
Authors: Amano Shigeaki , Yamakawa Kimiko
Published: October 2014

Previous studies suggested that a plosive-type geminate stop in Japanese is discriminated from a single stop with variables of stop closure duration and subword duration that spans from the mora preceding the geminate stop to the vowel following the stop. However, this suggestion does not apply to a fricative-type geminate stop that does not have a stop closure. To overcome this problem, this study proposes Inter-Vowel Interval (IVI) and Successive Vowel Interval (SVI) as discriminant variables. IVI is the duration between the end of the vowel preceding the stop and the beginning of the vowel following the stop. SVI is the duration between the beginning of the vowel preceding the stop and the end of the vowel following the stop. When discriminant analysis was conducted between single and geminate stops of plosive and fricative types using IVI and SVI as independent variables, the discriminant ratio was very high (99.5%, n = 368). This result indicates that IVI and SVI are the general variables that represent acoustic features distinguishing Japanese single and geminate stops of both plosive and fricative types. [This study was supported by JSPS KAKENHI Grant Numbers 24652087, 25284080, 26370464 and by Aichi-Shukutoku University Cooperative Research Grant 2013-2014.]
Perceptual distinctiveness of dental vs. palatal sibilants in different vowel contexts
Authors: Li Mingxing
Published: October 2014

This paper reports a similarity rating experiment and a speeded AX discrimination experiment to test the perceptual distinctiveness of dental vs. palatal sibilants in different vowel contexts. The stimuli were pairs of CV sequences where the onsets were [s, ts, tsʰ] vs. [ɕ, tɕ, tɕʰ] as in Mandarin Chinese and the vowels were [i, a, o]; the durations of the consonants and vowels were set to values close to those in natural speech; the inter-stimulus-interval was set at 100ms to facilitate responses based on psychoacoustic similarity. A significant effect of vowel contexts was observed in the similarity rating by 20 native American English speakers, whereby the dental vs. palatal sibilants were judged to be the least distinct in the [i] context. A similar pattern was observed in the speeded AX discrimination, whereby the [i] context introduced slower “different” responses than other vowels. In general, this study supports the view that the perceptual distinctiveness of a consonant pair may vary with different vowel contexts. Moreover, the experiment results match the typological pattern of dental vs. palatal sibilants across Chinese dialects, where contrasts like /si, tsi, tsʰi/ vs. /ɕi, tɕi, tɕʰi/ are often enhanced by vowel allophony.
The role of prosody in English sentence disambiguation
Authors: Miller Taylor L.
Published: October 2014

Only certain ambiguous sentences are perceptually disambiguable. Some researchers argue that this is due to syntactic structure (Lehiste 1973, Price 1991, Kang & Speer 2001), while others argue prosodic structure is responsible (Nespor & Vogel 1986 = N&V, Hirshberg & Avesani 2000). The present study further tests the role of prosodic constituents in sentence disambiguation in English. Target sentences were recorded in disambiguating contexts; twenty subjects listened to the recordings and chose one of two meanings. Following N&V’s experimental design with Italian, the meanings of each target structurally corresponded to different syntactic constituents and varied with respect to phonological phrases (ϕ) and intonational phrases (I). The results confirm N&V’s Italian findings: listeners are only able to disambiguate sentences with different prosodic constituent structures (p < 0.05); those differing in (I) but not (ϕ) have the highest success rate—86% (e.g., [When danger threatens your children]I [call the police]I vs. [When danger threatens]I [your children call the police]I ). As reported elsewhere (e.g., Lehiste 1973), we also observed a meaning bias in some cases (e.g., in “Julie ordered some large knife sharpeners,” listeners preferred “large [knife sharpeners]” but in “Jill owned some gold fish tanks,” they preferred “[goldfish] tanks”).
Perceptual isochrony and prominence in spontaneous speech
Authors: Morrill Tuuli , Dilley Laura , Forsythe Hannah
Published: October 2014

While it has been shown that stressed syllables do not necessarily occur at equal time intervals in speech (Cummins, 2005; Dauer, 1983), listeners frequently perceive stress as occurring regularly, a phenomenon termed perceptual isochrony (Lehiste, 1977). A number of studies have shown that in controlled experimental materials, a perceptually isochronous sequence of stressed syllables generates expectations which affect word segmentation and lexical access in subsequent speech (e.g., Dilley & McAuley, 2008). The present research used the Buckeye Corpus of Conversational Speech (Pitt et al., 2007) to address two main questions (1) What acoustic and linguistic factors are associated with the occurrence of perceptual isochrony? and (2) What are the effects of perceptually isochronous speech passages on the placement of prominence in subsequent speech? In particular, we investigate the relationship between perceptual isochrony and lexical items traditionally described as “unstressed” (e.g., grammatical function words), testing whether these words are more likely to be perceived and/or produced as prominent when they are preceded and/or followed by a perceptually isochronous passage. These findings will contribute to our understanding of the relationship between acoustic correlates of phrasal prosody and lexical perception. [Research partially supported by NSF CAREER Award BCS 0874653 to L. Dilley.]
Prominence, contrastive focus and information packaging in Ghanaian English discourse
Authors: Lomotey Charlotte F.
Published: October 2014

Contrastive focus refers to the coding of information that is contrary to the presuppositions of the interlocutor. Thus, in everyday speech, speakers employ prominence to mark contrastive focus such that it gives an alternative answer to an explicit or implicit statement provided by the previous discourse or situation (Rooth, 1992), and plays an important role in facilitating language understanding. Even though contrastive focus has been investigated in native varieties of English, there is little or no knowledge of similar studies as far as non-native varieties of English, including that of Ghana, are concerned. The present study investigates how contrastive focus is marked with prosodic prominence in Ghanaian English, and how such a combination creates understanding among users of this variety. To achieve this, data consisting of 61/2 hours of English conversations from 200 Ghanaians were analyzed using both auditory and acoustic means. Results suggest that Ghanaians tend to shift the contrastive focus from the supposed focused syllable onto the last syllable of the utterance, especially when that syllable ends the utterance. Although such tendencies may shift the focus of the utterance, the data suggest that listeners do not seem to have any problem with speakers’ packaging of such information.
The representation of tone 3 sandhi in Mandarin: A psycholinguistic study
Authors: Chien Yu-Fu , Sereno Joan
Published: October 2014

In Mandarin, tone 3 sandhi is a tonal alternation phenomenon in which a tone 3 syllable changes to a tone 2 syllable when it is followed by another tone 3 syllable. Thus, the initial syllable of Mandarin bisyllabic sandhi words is tone 3 underlyingly but becomes tone 2 on the surface. An auditory-auditory priming lexical decision experiment was conducted to investigate how Mandarin tone 3 sandhi words are processed by Mandarin native listeners. The experiment examined prime-target pairs, with monosyllabic primes and bisyllabic Mandarin tone 3 sandhi targets. Each tone sandhi target word was preceded by one of three corresponding monosyllabic primes: a tone 2 prime (Surface-Tone overlap) (chu2-chu3li3), a tone 3 prime (Underlying-Tone overlap) (chu3-chu3li3), or a control prime (Baseline condition) (chu1-chu3li3). In order to assess the contribution of frequency of occurrence, 15 High Frequency and 15 Low Frequency sandhi target words were used. Thirty native speakers of Mandarin participated. Results showed that tone 3 sandhi targets elicited significantly stronger facilitation effects in the Underlying-Tone condition than in the Surface-Tone condition, with little effect of frequency of occurrence. The data will be discussed in terms of lexical access and the nature of the representation of Mandarin words.
Perception of sound symbolism in mimetic stimuli: The voicing contrast in Japanese and English
Authors: Grass Kotoko N. , Sereno Joan
Published: October 2014

Sound symbolism is a concept in which the sound of a word and the meaning of the word are systematically related. The current study investigated whether the voicing contrast between voiced /d, g, z/ and voiceless /t, k, s/ consonants systematically affects categorization of Japanese mimetic stimuli along a number of perceptual and evaluative dimensions. For the nonword stimuli, voicing of consonants was also manipulated, creating a continuum from voiced to voiceless endpoints (e.g., [gede] to [kete]), in order to examine the categorical nature of the perception. Both Japanese native speakers and English native speakers, who had no knowledge of Japanese, were examined. Stimuli were evaluated on size (big–small) and shape (round–spiky) dimensions as well as two evaluative dimensions (good–bad, graceful–clumsy). In the current study, both Japanese and English listeners associated voiced sounds with largeness, badness, and clumsiness and voiceless sounds with smallness, goodness, and gracefulness. For the shape dimension, however, English and Japanese listeners showed contrastive categorization, with English speakers associating voiced stops with roundness and Japanese listeners associating voiced stops with spikiness. Interestingly, sound symbolism was very categorical in nature. Implications of the current data for theories of sound symbolism will be discussed.