bluuebunny/crossref_metadata_2025 huggingface dataset:
Comodulation detection differences and comodulation masking release with multiple cue bands
Authors: Wright Beverly A. , McFadden Dennis
Published: October 2005

Detection thresholds were determined for a noise band signal centered at 2500 Hz in the presence of four additional “cue” bands at 1500, 2000, 3000, and 3500 Hz. Contrary to the typical results of comodulation masking release (CMR), subjects were 6–12 dB more sensitive when the signal band's temporal envelope was uncorrelated with the four correlated cue bands than when all five of the bands were correlated. We refer to this difference in detectability as a comodulation detection difference (CDD). Interestingly, when none of the five bands was correlated, performance was essentially the same as when all five of the bands were correlated. The method was two-interval forced choice. The signal and the cue bands were computer synthesized and were all 100 Hz wide. Different noise samples were presented within and across trials. Results will also be presented for CDD conditions in which different subsets of the four cue bands were correlated, in which the cue bands had different center frequencies, and in which fewer cue bands were used. In addition, data will be presented from more traditional CMR conditions in which a 2500-Hz tone was masked by a noise band centered among the same cue bands used in the CDD experiments. [Work supported by NINCDS.]
The overshoot effect in impaired and normal ears
Authors: Carlyon Robert P. , Sloan Eileen P.
Published: October 2005

The threshold for the detection of a brief tone masked by a longer duration noise burst is higher when the tone is presented shortly after the onset of the noise than at longer delay times. This finding has been termed the “overshoot” effect [E. Zwicker, J. Acoust. Soc. Am. 37, 653–663 (1965)]. This experiment compared the size of the effect in the normal and impaired ears of five subjects with high-frequency unilateral hearing loss of sensorineural origin. Thresholds were measured for 5-ms, 4-kHz tones presented 10, 200, and 390 ms after the onset of a 400-ms, 2–8 kHz noise burst. The better ear of each subject was tested using two noise levels, one equal in sound-pressure level and one in sensation level to that used for the impaired ear. Thresholds for all subjects and all ears decreased monotonically with increasing delay time, the size of the effect being 5 dB. Thus a small overshoot effect was observed regardless of hearing impairment.
Intraspeaker variability on nasal consonant [m]
Authors: Oyer Herbert J. , Qi Yingyong , Lambert Claude
Published: October 2005

Our previous study determined that intraspeaker variability is small for the first formant of the nasal/m/when read in a carrier sentence and larger when read in a paragraph. This study investigates factors responsible for increase in intraspeaker variability. Syllables [mi], [ma], and [mu] were each read ten times and recorded (1) in a carrier sentence with a slow rate, (2) in a carrier sentence with rapid rate, and (3) in a paragraph with normal reading rate. First formant frequency contours were compared to determine effects of context and rate on intraspeaker variability. Findings suggest that intraspeaker variability of the nasal /m/ is closely related to context, but rate of utterance is somewhat unimportant. The implication is that, although the /m/ is produced within a vocal tract that remains relatively constant, it is still subject to some variation due to the effects of coarticulation. A comprehensive study of the sounds subject to the least coarticulatory effects may prove to be important in speaker identification.
VOT variability: Within-subject and between-subject measurements of stop-consonant production by female talkers of English, Japanese, Navajo, and Spanish
Authors: Lauter Judith L. , Pearl Nancy B.
Published: October 2005

Voice onset time (VOT) presents the language learner with a problem in temporal perception and generalization. However, the variability of this cue in real-speech tokens has not been reported. Two female native talkers for each of four languages—English, Japanese, Navajo, and Spanish—produced six repetitions of their native-language stop consonants in a nonsense syllable form: ha-ba, ha-da, etc. Talkers sat in an anechoic chamber 0.5 m from an AKGC451E microphone and self-monitored syllable peak levels using a sound level meter. Productions were digitized (Nakamichi DMP100 pulse-code modulator) and stored on videotape (Fisher 805A video cassette recorder). The VOTs were measured from waveforms produced on a Kay 7800 digital sonograph. Results illustrate: (1) individual differences in VOT patterns; (2) patterns of absolute-value range that are language specific; (3) less consistency in actual VOTs than suggested in the synthetic-speech literature; and (4) the need for a multi-cue study of phoneme perception in order to examine individually characteristic trade-offs among cues that may be the rule rather than the exception in real speech. [Work supported by AFOSR.]
Acoustic properties of geminate consonants
Authors: Lahiri Aditi , Hankamer Jorge
Published: October 2005

It is generally assumed in informal descriptions that what distinguishes geminate from nongeminate consonants is duration of articulation. This has not, however, been demonstrated instrumentally, nor are informal descriptions precise about what should be measured. To study the acoustic features of geminates, we investigated geminate stops in Turkish, comparing geminate and nongeminate stop consonants in similar environments. We measured the duration from the beginning of the preceding vowel to the beginning of the consonant closure, the pause duration from the end of the preceding vowel to the beginning of the following consonant, the duration of consonant closure, and the ratio of the rms energy at the onset of the consonant to that of the following vowel. The only significant difference was the duration of the pause. To investigate the perceptual salience of this feature, we took 20 minimal pairs of geminates and nongeminates, cross spliced the pause, and presented a randomized set of words to native speakers of Turkish, who wrote down what they heard. The pause was found to be a significant cue in discriminating between geminate and nongeminate consonants.
Vowels and diphthongs in Icelandic
Authors: Jackson Michel T. T.
Published: October 2005

A factor model for midsagittal x rays of the Icelandic long and short vowels [i, I, e, y, ø, u, o, a] [M. Pétursson, Phonetics 29 (1–2), 22–79 (1974); M. Pétursson, Les Articulations de l'Islandais à la Lumière de la Radiocinématographie (Klincksieck, Paris, 1974)] was constructed. The factor model is based on single frames from the center of the vowels, and accounts for 95% of the variance in tongue positions with three factors. Sequences of x rays of the long and short diphthongs [ei, øi, ai, ou, au] including portions of the consonantal on- and off-glides can be described by the same factors (> 80% of the variance accounted for). We approximate the trajectories of the diphthongs by constructing curves that interpolate the measured positions in factor space. Examining the trajectory through factor space suggests an articulatory parametrization of diphthongs. [Work supported by NIH.]
Vowel features in Akan and English
Authors: Lindau-Webb Mona
Published: October 2005

Height and backness are basic vowel features in most languages. Even large vowel systems, like English, can be contrasted with only these two features. When languages have additional contrasts, such as advanced tongueroot, these features are treated as if they are combined with height and backness in an additive way. The harmonizing vowels of Akan are usually described by height and back, and advanced tongueroot for the vowel harmony. Are these three features of Akan vowels phonetically the same as those in English, with an added feature of advanced tongueroot, or are they organized differently? Using PARAFAC-analysis, Harshmann et al. [“Factor analysis of tongue shapes, J. Acoust. Soc. Am. 62, 693–707 (1977)] found that the tongue shapes of English vowels are controlled by two parameters. The tongue shapes of Akan vowels from four speakers were analyzed in the same way. The results show that the tongue shapes of Akan vowels are controlled by two mechanisms, which are different from those used by English speakers. Thus the “same” features in different languages are controlled differently, and when more features are required, these are not simply added, but require a different organization and integration of the controlling mechanisms. [Work supported by NIH.]
Long-range arrival structure using timefront analysis
Authors: Bold Gary E. J. , Birdsall Theodore G. , Metzger Kurt
Published: October 2005

If the classical differential equations defining rays are rewritten in terms of travel time instead of ray path distance, it is straightforward to trace families of rays from a point with time as the independent variable. Points on rays having the same time coordinate define a timefront surface, thus designated to emphasize its high-frequency nature. Timefronts are spherical at short ranges, slowly evolving into an accordian structure. The shape of the timefront changes relatively slower over time scales of seconds, enabling a physical picture of long distance arrival times to be seen by inspection. A simple algorithm for deducing accurate travel times of eigenrays to a given receiver steps the timefront iteratively until its branches cross the receiver coordinates. Several features characteristic of long distance arrival structure are demonstrated. Numerical results from typical profiles, some including surface ducts, are presented.
Inversion of data for propagation over graveled surfaces
Authors: Lucas R. J. , Twersky V.
Published: October 2005

Data obtained by Medwin and D'Spain [J. Acoust. Soc. Am. 79, 657 (1986)] for low-frequency, near-grazing propagation over gravel-covered rigid planes are inverted by applying the procedure developed earlier [Lucas and Twersky, J. Acoust. Soc. Am. Suppl. 1 79, S68 (1986)] for regularly shaped protuberances. The development is based on analytical results for a point source irradiating an embossed plane, and on the uniform asymptotic representation of the coherent field as a Sommerfeld type wave system in terms of the complex error function complement Q [J. Acoust. Soc. Am. Suppl. 1 74, S122 (1983); 76, 1847 (1984)]. Initial estimates of unknown parameters are obtained by working with elementary approximations of the Q integral, and then using the complete integral for refinements and final computations. The corresponding graphical results display the primary data trends for the magnitudes of the normalized fields and for the incremental dispersion (phase velocity) versus frequency at different ranges. The procedure delineates the roles of interference and damping on the elementary wave components of the Sommerfeld type system.
Basic problems in designing to control noise intrusion
Authors: Quirt J. D.
Published: October 2005

Intrusion of outdoor noise into buildings interferes with many activities. This activity interference can be controlled by proper design and construction of the building's exterior envelope. Specifying that all components should have sound transmission class (STC) ratings equal to the desired difference between outdoor and indoor A-weighted sound levels would have an appealing simplicity, but has several shortcomings. These are detailed in the course of presenting a straightforward procedure for determining suitable STC values for the components of the exterior envelope. Particular attention is given to dependence of the noise reduction on characteristics of the exterior sound field and the sound transmission properties of the building envelope.
The coincidence dip in window sound transmission
Authors: Schaffer Mark E.
Published: October 2005

Glazing selections for exterior wall constructions are usually made on the basis of 1/3-octave-band sound transmission loss as measured in a dual reverberation room test facility. This selection method is generally acceptable where the exterior sound is broadband in nature. Under these conditions the coincidence effect, which is responsible for a drop in transmission loss performance, is blurred over upper frequencies and is barely noticeable to a building occupant. However, when the exterior noise contains significant amounts of sound energy in the coincidence frequency range and the sound is incident over a varying angle (e.g., an aircraft flyby or a heavy truck driveby), the coincidence effect causes the glass to act as a sweeping narrow bandpass filter which can be most annoying to a building occupant. Results of field tests will be shown to verify the angular dependency and the strength of the effect in narrow bandwidths. Audio recordings will be played to demonstrate the relationship between the coincidence effect and the angle of incidence of direct field noise.
Transducer modeling using axial profile fitting techniques
Authors: Bennink David , Mielnicka-Pate Anna L.
Published: October 2005

Axial profiles of three piezoelectric, nonfocused, immersion pulse-echo transducers were measured using a small spherical reflector and an automatic scanning device. The scanning distance range included the first and second maxima. Measured data were compared with rigid disk radiation theory. The frequency-dependent active radius was used as a parameter in the curve fitting. In addition, three different approaches were used in the curve fitting. These included (1) fitting the entire range of the scanning distances, (2) fitting the first maximum, and (3) fitting the second maximum. The results of fitting the first maximum agree extremely well with the entire curve fitting, while the results obtained from the second maximum contain more errors. The results of modeling the transducers will be discussed in terms of the active radii and spatial sensitivity functions. In general, good agreement between the theoretical and experimental results was obtained. [Work supported by Center for NDE, Ames, Iowa.]
An acoustic sensor utilizing a twisted birefringent fiber
Authors: Hu Andong , Cuomo Frank W.
Published: October 2005

The results of the light propagation in the linear twisted birefringent fiber using the parallel method have been obtained [H. G. Winful, Appl. Phys. Lett. 47, 213–215 (1985)]. A conceptual design of an acoustic optical fiber sensor and the numerical calculations are given based on the amount of twist about the fiber axis generated at the output fiber end by an acoustic pressure field. If the input power, coupled into the birefringent fiber at 45°, is assumed to be 0.5 mW, and the induced output optical power is assumed to be 1.62 × 10−9 W under the twist rate condition of 1 second of arc, the minimum detectable pressure is on the order of 26 dB re: 1 μPa/Hz and the approximate modulation index is 3 × 10−3/Pa. The active area of the probe can be on the order of 1 mm and the predicted frequency response is quite broad. These results are favorable in comparison with other optical fiber pressure sensors proposed in the literature.
Waves-scatter bond graphs for electroacoustic systems
Authors: Paynter Henry M. , Busch-Vishniac Ilene J.
Published: October 2005

Electroacoustics was born as a twin to the telephone 110 years ago. Today electroacoustic transduction involves a sophisticated science and technology. Early in this evolution alternating currents and electrical oscillations were compared to the better-understood mechanical vibrations, but electro-technology advanced so rapidly that mechanical systems were soon treated conversely by analogous electrical circuits. Yet because a strict correspondence does not exist at the microscopic and continuum levels, several alternative analogies emerged so that now engineers confront a lack of uniform methodology, particularly when dealing with distributed transducers. Bond graphs were developed to meet just such needs by treating all physical systems as a set of multiport elements richly interconnected by another set of power bonds, which together enforce continuity-conservation laws for mass, momentum, charge, and energies. Furthermore, to provide self-consistent signal causality and detailed balances of power dissipation and entropy production, scattering variables can be employed at all ports, and wave variables on all bonds. Such characteristic variables and their methods of use were first introduced by Bernhard Riemann in 1860 for finite amplitude sound waves and later reintroduced in the 1940s for microwave circuitry. Some applications are given of this powerful approach to practical electroacoustical devices and systems.
The performance of an optical fiber pressure probe for ultrasonic studies
Authors: Cuomo Frank W. , Hu Andong
Published: October 2005

It has been suggested that the three-dimensional quantitative characterization of ultrasonic fields be determined utilizing a miniature optical fiber pressure probe [F. W. Cuomo, 12th International Congress on Acoustics (ICA), Toronto, Canada, paper G7-3 (1986)]. This approach has been found useful in extending experimentally the two-dimensional quantitative information now available with Schlieren imaging methods. In this paper, the experimental results of the ultrasonic optical fiber sensor related to pressure sensitivity, frequency response, and directionality are presented. The active area of this probe is less than 1 mm and the frequency range of interest lies between 500 kHz and 2 MHz.
Educating Americans for the 21st century
Authors: Collea Francis P.
Published: October 2005

Recent national commission reports have discussed a new era for science education. Unlike the sciences of the 1950s and 1960s, this new era has raised some provocative questions concerning science education for the future. The science movements of the post-sputnik period stressed science for the elite, more science and mathematics for the college-bound student, developing a corps of the very best engineers and scientists who could take us to the moon and let us assume the leadership in the international scientific enterprise. It was a time whose purpose was to get the most able students from our high schools into the calculus and physics courses at universities and colleges as quickly as possible. The recent report of the National Science Board's Commission on Precollege Education in Mathematics, Science, and Technology represents a radical departure from the movements of the 50s and 60s. The purpose of this paper is to discuss the implications of their recommendations for the future of science education.
Educational applications of microcomputer-based sound apparatus
Authors: Hanson Roger J. , Ward Robert T.
Published: October 2005

Some educational uses of the equipment described in the previous paper [R. J. Hanson and R. T. Ward, J. Acoust. Soc. Am. Suppl. 1 80, S72 (1986)] will be described and demonstrated. It can be used to study waveforms for different sounds, measure frequencies, study voice prints (simple sound spectrograms), generate various types of sounds, and measure the speed of sound in air. Experiences of its use with junior high school students will be reported. Suggestions for use with other audiences will be given.
Hands-on musical acoustics in the elementary classroom
Authors: Ayers R. Dean
Published: October 2005

The author has developed a minicourse for school teachers on how they can include acoustics in their teaching of science, with particular emphasis on musical sounds. The organizing theme is the direct, hands-on accessibility of many basic ideas in this area. The course is divided into three units: (1) simple vibrators, covering ideas about pitch, frequency, mass, and stiffness; (2) vibrators with several natural frequencies, presenting concepts of standing waves, nodes, and techniques for manipulating the sounds from such a vibrator; and (3) sound waves themselves, with emphasis on the wind instruments. An important part of each unit is the “dessert”—a simple musical toy whose operation illustrates the ideas discussed: (1) a seven-note, pentatonic thumb harp (African sansa or kalimba) constructed from materials indigenous to the American shopping center; (2) a tromba marina (bowed monochord), also built from cheap, readily available materials; and (3) a “flugle”—a closed/open cylindrical whistle on which bugle calls can be played. A color code for pitch makes it easy for beginners to play familiar tunes.
Aspect ratio dependence of forward scattered form functions
Authors: Norton Guy , Werby M. F.
Published: October 2005

It is usual to examine backscattered form functions when scattering from submerged objects. For such calculations frequency is allowed to vary over a broad range in small step sizes yielding resonance information and circumferential diffraction effects. For ka values approximately 5 or greater (here k is the wavenumber and a is a characteristic dimension) the form function remains at a fixed value with pronounced fluctuations at resonance locations. Forward-scattered form functions, however, continue to increase in value. Though they are not apparently as useful in the extraction of resonance information, calculations presented here indicate that the rate at which they increase with increasing frequency may be associated with the aspect ratio of the target, providing one limits calculations to end-on incidence.
Comparison of scattering from elastic shells and end-on incident scattering from elastic spheroidal shells
Authors: Werby M. F. , Green L. H.
Published: October 2005

Until fairly recently it has not been possible to perform exact calculations of scattering from nonspherical three-dimensional elastic shells. However, due to the extended boundary condition method (EBC) of Waterman, such calculations are presently possible. Both as a check of current numerical codes, and because of an interesting physical observation, a comparison of scattering from submerged spherical shells, and end-on incident scattering from spheroidal shells of the same material are presented in this work. The spherical calculations are performed using a normal mode code and the spheroidal calculations are performed using a code based on the EBC method for aspect ratios ranging from 1 to 3 for two different shell thicknesses. A comparison of the spheroidal form function with that of the spherical case illustrates a one-to-one correspondence between the two in which the form function of the spheroidal cases appear as stretched spherical calculations. This stretching effect is easily explained using the standing wave theory of resonances proposed by Werby and Gaunaurd.
Vowel discrimination in primates
Authors: Sinnott Joan M. , Kreiter Nancy A.
Published: October 2005

Discrimination often steady-state synthetic English vowels was measured in Old World monkeys (Macaca, Cercopithecus) and humans using a repeating standard AX procedure and positive-reinforcement operant conditioning techniques. All monkeys had difficulty discriminating spectrally similar vowels such as |ɑ-Λ| and |ν-μ|, but macaque monkeys were superior to cercopithecus monkeys. Human reaction times reflected spectral similarity and correlated with monkey percent correct discriminations. Macaque DLs for formant frequency changes along vowel continuua |ε-æ| and |i-ɪ| were about 30 Hz, compared to about 10 Hz for humans. Formant filtering and sensation level variation had only minor effects on DLs. Results are related to other comparative psychoacoustic data and vocal communication in the various monkey species. [Work supported by NIH and the Deafness Research Foundation.]
Auditory sensitivity of two strains of the common canary (Serinus canarius)
Authors: Dooling Robert J. , Okanoya Kazuo
Published: October 2005

Adult canaries from two strains of canaries (Belgian Waterslager and German Roller) were trained with operant conditioning techniques for audiometric testing. Absolute thresholds for canaries from the German Roller strain were similar to those previously reported for other small birds including canaries. At frequencies above 2.0 kHz, absolute thresholds for canaries from the Belgian Waterslager strain were 30–50 dB higher than those of German Roller canaries. The spectral distribution of energy in the calls of the two species parallels the species differences in absolute thresholds. Absolute thresholds of F 1 hybrids of a male Belgian Waterslager and a female German Roller canary also show elevated high-frequency thresholds. These findings suggest that strain differences in auditory thresholds in the canary may have a genetic basis. The results are discussed in relation to selective breeding and song learning in domestic canaries. [Work supported by NIH.]
Temporal limits of frequency discrimination in the components of two Bobwhite Quail (colinus virginianus) calls
Authors: Gatehouse R. W.
Published: October 2005

Previous studies using operant training/testing regimes (Barton et al., 1984; Bailey et al., 1985) have determined audibility curves and frequency discrimination capabilities of the Bobwhite Quail (colinus virginianus) with a view to delineating the functional significance of various components in the birds' calls. The present studies required two groups of four birds to discriminate between predominant frequencies (1.0 and 3.5 kHz) which are significant in the adult separation and chick “lost” calls, respectively, under varied peak frequency temporal durations. Three studies were done: (1) the rewarded “group correct” signals (e.g., 1.0 kHz) and the competing signals (e.g., 3.5 kHz) durations were successively and equally decreased; (2) the competing signal was held constant (200 ms) while the group correct was decreased; (3) each “correct” frequency of 200 ms was compared against itself with durations less, equal, or greater than 200 ms. The results suggest that in the field where the quail must extract species specific information about conspecifics from the “noise” of other similar/dissimilar signaling (cross species and environmental noises) and from the similar frequencies, durations, and sequences put out by within species competitors, the signals must be at least 100 ms to have salience. The significance of such call component analysis in bird communciaton and survival will be discussed.
The perception of temporally modified conversational and clear speech by hearing-impaired listeners
Authors: Uchanski R. M. , Braida L. D. , Durlach N. I. , Reed C. M.
Published: October 2005

Hearing-impaired listeners find clearly articulated speech more intelligible than conversational speech [M. A. Picheny et al., J. Speech Hear. Res. 28, (1985)]. Acoustical measurements indicate that the temporal characteristics of clear and conversational speech differ [M. A. Picheny et al., J. Speech Hear. Res. (in press)]. In particular, clearly articulated segments are nonuniformly longer than the corresponding segments in conversational speech [R. M. Uchanski et al., J. Acoust. Soc. Am. Suppl. 1 77, S54 (1985)]. For example, the percent increase in duration for fricatives and diphthongs is much larger than that for short vowels and voiced plosives. To evaluate the importance of these temporal differences we have measured the intelligibility of two types of processed speech materials: conversational speech with nonuniformly increased segment durations and clear speech with nonuniformly compressed segment durations. Results from several hearing-impaired listeners will be discussed. [Work supported by NIH.]
Transformations of voice fundamental frequency for a vibrotactile device to aid lipreading
Authors: Eberhardt Silvio P. , Bernstein Lynne E.
Published: October 2005

As part of the development of a wearable vibrotactile device to convey voice fundamental frequency F0 to hearing-impaired lipreaders, a study was conducted to compare transforms of F0. Rothenberg and Moliter [J. Acoust. Soc. Am. 66, 1029–1038 (1979)] reported that most errors in a tactile-alone task of judging stress and intonation in sentences were mislocations of the stressed word. We found that contrastive stress can be detected visually. The present experiment compared F0 transforms in a tactual-visual task. Transforms included: (1) direct glottal to tactile pulse; (2) linear transform with lowering of center frequency and shift in range; (3) similar to (2) with log of the normalized glottal period; (4) similar to (2) with the difference of logs of the current period and a weighted sum of previous periods; and (5) a constant pulse train during voicing. Subjects received tactile stimulation to the index finger by an AV-6 vibrator, and responses were labeled “question” or “statement” and one of three stress positions. Effects of the transforms and conditions of vision-only versus tactual-visual presentation will be reported. [Work supported by NIH.]
Jaw kinematics in hearing-impaired speakers
Authors: McGarr Nancy S. , Lofqvist Anders , Story Robin Seider
Published: October 2005

This study examines jaw movements as a function of vowel height and stress in real-word phrases produced by three hearing-impaired speakers and a hearing control. Movements of the lips and jaw were recorded using an optical tracking system. Measures included duration, displacement, and peak velocity of movement. There were statistically significant main effects for vowel height in nearly all movement records for both the hearing-impaired and the hearing speakers. However, the related measures for stress had no significant effects for the subjects. The hearing speaker distinguished stressed and unstressed segments by maintaining the jaw in a lowered position for a longer period in the stressed vowels. With few exceptions, kinematic values for the hearing and the hearing-impaired speakers were comparable. These results thus suggest that some characteristics of speech production are not adversely affected by congenital and profound hearing loss. [Work supported by NIH.]
An integrated voice analyzer for evaluating pathological voice
Authors: Kikuchi Yoshinobu , Uchida Satoshi , Kasuya Hideki
Published: October 2005

We have developed an integrated voice analyzer (IVA) using DSP (TMS32010) to achieve high-speed acoustic analyses of a sustained vowel. A personal computer connected to the IVA is employed as the man-machine interface as well as to display and save various analysis results. The IVA has many functions, such as detecting vocal noise by an adaptive comb filter, measuring period and amplitude perturbation quotients, calculating DFT spectra and LPC coefficients, etc. The results are stored into a disk file to do statistical analysis or to perform further analyses. This system provides an interactive acoustic analysis method for quantitative evaluations of the pathological voice arising in various voice research and clinical areas. We describe an application of the IVA for the clinical screening system for pathological voices, where hoarseness grade (HG) of a voice can be obtained from five sustained phonations. [Work supported by a Japanese Grant-in-Aid for Scientific Research.]
The acoustical signature for intelligibility test words: Population profiles for neurologically intact, geriatric speakers
Authors: Weismer Gary , Kent Ray D. , Hodge Megan
Published: October 2005

A common approach to the clinical assessment of disordered speech is to obtain intelligibility scores for lists of single-word or sentence items. Whereas such scores provide an index of speech deficit severity, they give no insight to the acoustic basis of the deficit. A test that would allow specification of the acoustical basis of an intelligibility deficit should (1) incorporate word items that sample systematically the acoustical contrasts that cue differences in meaning, and (2) have as a foundation an empirically based model of the “normal” acoustical characteristics for each word in the test. In the present paper, speech profiles of selected intelligibility words from a closed-set test are presented for a relatively large group of geriatric speakers (N = 15, 15 females). Consideration will be given to ways of representing the normal population space for various acoustical events of speech, and selected data from dysarthric speakers will be presented to illustrate the application of this approach to a clinical population. [Work supported by NIH.]
Distributed acoustical assimilation in the equatorial Pacific Ocean
Authors: Clarke Thomas L. , Proni John R.
Published: October 2005

The possibility of using a dynamical-model-based equatorial ocean data assimilation technique as the basis for tomographic inversion is explored. In the equatorial Pacific relatively few ray paths come near the surface causing difficulty for most inversion techniques. A data assimilation technique being developed at the Physical Oceanography Division of AOML/NOAA [Thacker and Long, in preparation] uses a dynamical approach that can provide coupling between the deep conditions that are directly sensed by the acoustics, and the near surface events that are of direct climatic significance. The model decomposes temperature variability into dynamical modes identifiable with Kelvin and Rossby waves; the sensitivity of individual ray-path travel times to the modes is used as the basis for the inversion. The acoustic data is assimilated with other ocean measurements by using a LaGrange multiplier approach constrained by the dynamics. Ray tracing results using equatorial Pacific temperature data are presented which show the promise of dynamical-model assimilation based tomographic inversion as a means of detecting near surface temperature anomalies in the equatorial Pacific.
High-resolution time of arrival estimation via linear prediction
Authors: Kirsteins Ivars P.
Published: October 2005

A new method is presented for estimating the arrival times of overlapping signal pulses that are separated by less than the duration of the signal autocorrelation function. The method is based on the observation that if the signal has a flat band-limited spectrum, then the maximum-likelihood estimator for the time of arrivals can be approximately transformed into an equivalent high-resolution exponential parameter estimation problem. Then, an improved linear prediction algorithm [D. W. Tufts and R. Kumaresan, Proc. IEEE 70, 975–989 (1982)] for high resolution exponential parameter estimation is used to estimate the time of arrivals. The proposed method is computer simulated for two linear FM sweep signal pulses at various separations and signal-to-noise ratios. The simulation results are compared to the Cramer-Rao lower bound (CRLB). These results indicate performance close to the CRLB over a reasonable range of pulse separation and signal-to-noise ratios.
Community aircraft noise ordinance—Sound transmission considerations
Authors: Braslau David
Published: October 2005

The Twin Cities Metropolitan Council has established aircraft noise compability guidelines for major and intermediate airports. The Council has prepared a “Model Ordinance” to help communities meet these guidelines. It has adopted a “noise zoning overlay” concept based upon a review of ordinances from other communities in the U.S. and Europe. Interior noise levels were established during a one-day workshop in 1983; 45 dB was established as the A-weighted interior residential level, to be measured in the same units as exterior noise levels (Leq or Ldn). Compliance can be achieved through the use of specified STC values for building elements or through analysis by a “recognized acoustical specialist,” defined in the ordinance. Minimum required STC values were based upon the noise reduction needed for each land use category and noise impact zone as well as assumed standard values of relative building component area and associated STC, aircraft takeoff noise spectrum, angle of incidence, number of exterior walls, and room absorption coefficient. An exterior wall performance methodology and worksheet to assist in evaluation was developed and implemented on a LOTUS 1-2-3 worksheet. Noise reduction benefits of the State energy code were also evaluated. [Work supported in part by the Twin Cities Metropolitan Council.]
Exterior sound transmission through fenestration products—Do we need a new rating method
Authors: Tocci Gregory C.
Published: October 2005

The California Association of Window Manufacturers (CAWM) requested ASTM to develop test criteria and performance ratings for exterior sound control capabilities of fenestration products. This presentation considers the relationship between sound transmission class (STC) and traffic, aircraft, and rail noise reduction (NR) for a group of glass configurations tested by Monsanto. It will be shown that a clear relationship exists between glass STC and noise reduction, which depends upon source spectrum shape and glazing configuration. It will be shown that any new rating method would necessarily take the form of the glazing STC rating plus a constant related to source spectrum type. Other features of building exterior construction will be considered, as they affect the minimum acceptable NR required for fenestration in any particular application. This obviates any benefit that a new rating scheme, dealing more directly with fenestration products, might have over the current STC rating method. A simplified method for estimating minimum required STC will be presented which will provide the advantage that the CAWM now seeks through a new fenestration products sound transmission loss rating. [Work partly supported by Monsanto.]
Window design techniques for sound attentuation
Authors: Stark Thomas S.
Published: October 2005

Excellent sound attenuation can be obtained with high performance, double window construction methods by optimizing glass selection and addressing basic design and construction details. With careful attention to manufacturing standards, DeVAC Series ♯600 thermo-barrier acoustical windows have STCs in the 37–39 range, glazed with common 1/8-in. window glass at the exterior and interior. The design provides an air space separation of 2-in. between inner and outer lites. Isolation and sealing for thermal performance increases the acoustical performance without using laminated glass. Noise penetration is reduced by achieving a low rate of air infiltration with dense, double weatherstripping, and covering drain holes with valve flaps to exhaust water buildup and eliminate air path channels. Glazing with heavier, unequal thicknesses of glass (maximum 1/4-in.) increases STC to 48 dB. Further options that accept glass up to 1/2-in. thick, and increase the air space separation to as much as 8-in., enable incremental improvements in STC to a currently tested 56 dB. The windows install in new construction with standard installation methods and, with optional trim accessories, adapt to existing openings for retrofit. Acoustical performance of available glazing and frame configurations are documented by sound loss test reports. Case history applications review both new construction and replacement projects requiring sound control windows which are operable for emergency ventilation or life safety, thereby addressing points of concern for residential, lodging, and educational facilities. Field testing by independent acoustical consultants confirms that the acoustical performance of installed windows meet project specifications.
Vertical pump noise control enclosure
Authors: Morse Bonard E.
Published: October 2005

When water districts began changing pumping equipment, replacing submersibile pumps with vertical pumps, they discovered a significant increase in the noise radiated by their equipment. This paper describes and discusses an enclosure that reduces the radiated noise and provides ducted air in and out for cooling the electrical drive motor. Data will be presented showing the noise levels before and after installation of the enclosure both near and at several distances from the pump. In addition to noise reduction the enclosure results in cooler operating temperatures which in turn aids in extending the service life of the pumping equipment.
Transmission loss of double panels with different gases in the gap
Authors: Atwal Mahabir S.
Published: October 2005

Recently there has been a renewed and growing interest in increasing the transmission loss of structures without significantly increasing the mass of the structure. A common method of increasing the transmission loss of a panel is by the introduction of one or more additional panels with intervening air spaces. Such a multiple layer panel is much more effective than a single panel of equivalent mass. This paper describes the possibility of increasing the transmission loss of a double panel by using different gases in the gap. Experimental results are presented which show the effect on the transmissions of different gases in the gap. Results of preliminary theoretical analysis to predict the transmission loss of such double wall panels is also presented.
Reaction time and musical expectancy: Priming of chords with no partials in common
Authors: Bharucha Jamshed Jay , Stoeckig Keiko
Published: October 2005

Subjects were presented with two musical chords in succession, called the prime and target, respectively. The prime and target were either related (e.g., C and D major, respectively, sharing a parent key) or unrelated (e.g., C and F♯ major, respectively, sharing no parent key). Subjects judged, as quickly as possible, whether the target was in tune or out of tune. Response times for in-tune targets were faster when prime and target were related than when they were unrelated, suggesting that the prime generated expectancies for related targets. Priming occurred even when prime and target shared no partials. These results suggest that chordal expectancies generated by a musical context are not due solely to priming at the level of individual frequencies, but also involve priming at a more abstract level of chord function, implicating a cognitive representation of chord relationships. A network model of chord relationships is proposed whereby chord nodes activate related chord nodes via links to their parent key nodes.
Simulation of a player-clarinet system
Authors: Sommerfeldt Scott D. , Strong William J.
Published: October 2005

A time-domain simulation model has been developed for investigating the player-clarinet system. The three components which constitute the simulation model consist of the “subreed” system, reed, and clarinet. The “subreed” system (lungs, bronchi, trachea, and vocal tract) is represented in terms of an analogous circuit model to obtain the “subreed” pressure. The reed is represented as a damped, driven, nonuniform bar. The clarinet is represented in terms of its input impedance impulse response. A convolution of the impulse response with the volume flow through the reed aperture determines the mouthpiece pressure. Use of the model is valid for both small- and large-amplitude oscillations. Many of the nonlinearities associated with the clarinet are incorporated in the model in a rather natural way. Several vocal tract configurations are investigated to determine the influence of the vocal tract on the clarinet tone.
Impulse responses for reentrant discontinuities in bores
Authors: Lee Anthony S. , Ayers R. Dean
Published: October 2005

We establish an optical analogy for the processing of spherical wavefronts in conical bore segments. A reentrant discontinuity acts like a converging lens or mirror to give outgoing waves a more positive vergence than incoming waves [M.P. Keating, Am. J. Phys. 43, 766–769 (1975)]. Impulse responses for single interactions with such a discontinuity include exponentially growing wakes, which become unmanageable very quickly in digital convolutions. Geometrical considerations rule out a reentrant discontinuity existing in isolation, and its troublesome behavior is kept under control by multiple reflections involving another discontinuity of stronger, negative power. In closed systems this process shows a “sorcerer's apprentice” type of behavior, in which a temporary solution to the problem turns into the problem for the next cycle. Fortunately that problem becomes more deltalike as time progresses, and there is a tendency for it to be cancelled by a neighboring delta. In open systems the behavior is much tamer, with the extended response dying out very quickly. Our piecewise analytic results suggest some approximations which may be useful in digital convolutions.
Science in the service of the performing arts. Section II: The physical factors
Authors: Veneklasen Paul S.
Published: October 2005

The choral anomaly intrigues us into experiments that disclose clearer understanding of projection of sound from the stage. The relative acoustical power output of instruments is the primary factor. The directional characteristics of musical instruments play a dominant role. Precise acoustical model tests disclose the power of physical manipulation of acoustical factors. Proper placement of performers can combat the effects of body baffling and absorption on stage. Manipulation of the surfaces of the orchestra enclosure offers the acoustician great versatility for intersection balance.
Sound propagation and scattering in discrete random scatterers
Authors: Ishimaru Akira
Published: October 2005

Recent advances in the theory of sound propagation and scattering in discrete random scatterers are reviewed together with some examples and applications. We first discuss single scattering theory, transport theory, multiple scattering theory, and diffusion theory and their range of validity. Different theories are needed depending on whether the scatterers are tenuous or nontenuous. If the concentration is low (sparse), all the particles can be considered as independent scatterers, while pair correlation needs to be included if the concentration is high. If the particle sizes are much greater than a wavelength and the particle is tenuous, the small-angle approximation is applicable. The diffusion approximation is useful for small scattering particles. We also discuss amplitude and phase fluctuations and pulse propagation. If the concentrations vary in the propagation path and the medium is inhomogeneous, there are significant differences between the propagation characteristics of the plane wave and the spherical or beam wave. This also explains the so-called shower-curtain effect. Imaging through such discrete scatterers can be treated in terms of the modulation transfer function. Several experimental data are also presented.
Geometric theories for propagating statistical moments
Authors: McCoy John J. , Berman David H.
Published: October 2005

Ray-based models for propagating the statistical moments of a stochastic radiation field through an inhomogeneous, but deterministic, medium will be considered. The source of stochastic fluctuations in the radiation field in this case could be in the physical source itself, or in the interaction of an initially deterministic signal with a randomly rough boundary surface. The reradiated field in the latter case requires a stochastic description. Detailed calculations are considered for the second moment (signal coherence) and the fourth moment (intensity fluctuations and correlations) but the road to extensions to higher-order moments is discussed. The geometric theories are formulated as conservation laws written on certain Fourier transforms of the statistical moments. On the level of the two-point moment the Fourier transform is taken with respect to the difference coordinate, for the averaged coordinate held fixed. The form of the conservation law for wide angle, i.e., Helmholtz theory, propagation is presented as is the simplification obtained for narrow angle, i.e., parabolic wave theory, propagation. The question of caustic corrections in the context of a geometric theory of coherence is discussed. On the level of the four-point moment Fourier transforms are taken with respect to two of the Tartarski coordinates for locating the four points. Again the form of the conservation law for wide angle propagation is obtained first, and subsequent simplification introduced corresponding to the narrow angle approximation. The question as to when a complete theory can be formulated in terms of less than complete four-point information specified on a source plane is discussed. Incorporating a stochastic volume scatter mechanism into the basic formulisms is considered.