bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement of room-averaged spectra from complex sources
Authors: Benade A. H.
Published: October 2005

When a complicated source is turned on in a room, each of the earliest reflections arriving at the detector carries spectral information about the sound as radiated in a particular direction. However, the random phase shifts and attenuations of these successive arrivals lead ultimately to a steady-state signal whose spectral components each have a Rayleigh distribution with a spread of ±5.2 dB around a mean value obtainable via many readings taken at suitably spaced points throughout the room. Thus at least 27 properly chosen samples are required to give a precision of ±1 dB. In some cases FFT analysis of the arrivals before about (Trev/5) can provide roughly equivalent precision with fewer samples. There are indications that musical perception involves processes related to both the buildup-epoch and steady-state spatial-sampling procedures of the laboratory. Constraints on room size, reverberation time, intersample distance, source-to-detector distance, etc. (following Schroeder, Waterhouse, Lubman…) will be outlined. Examples of buildup-epoch and steady-state spatial-sampling measurements will be presented and compared. [Work supported by NSF.]
Laryngeal function: Electroglottograph, ultra-high-speed films, and speech inverse filtering
Authors: Krishnamurthy A. K. , Naik J. M. , Childers D. G.
Published: October 2005

Numerous methods have been devised to assess laryngeal function, including photography, inverse filtering of speech, electroglottography, and others. We have been conducting a series of experiments in which we record simultaneously the electroglottograph (EGG) waveform and the acoustic phonatory signal, while filming vibratory patterns of the vocal folds for both normal subjects and patients with various pathologies and vocal disorders. These data are synchronized via a special timing signal, which is recorded on the audio tape and ultra-high-speed laryngeal films. We present graphical plots of this synchronized data including (1) glottal area measured from the films, (2) the EGG waveform, (3) the speech waveform, and (4) the inverse filtered waveform. These results are being used in various ways including the verification that the EGG signal is indicative of the amount of contact between the vocal folds. Other uses of our results are obtaining better models of the source/tract coupling and the synthesis of more natural sounding speech.
The voice of dominance
Authors: Ohala John J.
Published: October 2005

Among animals dominance and aggression is conveyed in part by vocalizations with low fundamental frequency (F0), whereas submission is signalled by cries with high F0, e.g., growls and whines, respectively. It has been suggested that low and high resonances of vocalizations should serve the same function and that this helps to explain the origin of the smile, a nonaggressive signal, since retracting the corners of the mouth during a vocalization would raise the resonant frequencies [Ohala, “The acoustic origin of the smile,” J. Acoust. Soc. Am. Suppl. 1 68, S33 (1980)]. Do these acoustic parameters function similarly in human vocalizations? To investigate this, American English listeners were asked to listen to and to determine subjectively the relative “dominance” evident in voice samples that were actually synthetic speech samples devoid of recognizable lexical elements but varying in F0 and formant structure. Preliminary results suggest that perceived dominance is correlated inversely with overall F0 of voice. Further results will be presented and discussed in relation to current ethological theory. [Supported by the Harry Frank Guggenheim Foundation.]
Tuning curves in the presence of a simultaneous noise masker
Authors: Cudahy Edward A. , Geller Daniel
Published: October 2005

Psychoacoustic tuning curves for a 20-ms, 4-kHz signal were measured in quiet and in the presence of a 750-ms simultaneous noise masker. The signal was presented in the temporal center of the masker. The subjects were three normal listeners. The three noise masker conditions were low-pass 1 kHz, high-pass 5.5 kHz, and broadband. High-pass and broadband noises had little effect on tuning curves, whereas low-pass noise “detuned” the tuning curve by lowering the high-frequency slope. Implications of these findings for the role of suppression in measurements of frequency selectivity will be discussed.
Electrical stimulation of the auditory nerve: Membrane models applied to the interpretation of electrophysiological and psychophysical responses
Authors: White M. , Merzenich M.
Published: October 2005

Electrophysiological and psychophysical measures of threshold as a function of sinusoidal stimulus frequency deviate considerably from those predicted by Hill's membrane model. Using a modified Hodgkin-Huxley model, considerably better estimates of threshold were obtained over the frequency ranges investigated. The Hodgkin-Huxley model was modified by increasing the sodium inactivation rate constant, beta-h, by a factor of four. This model has been useful in interpreting electrophysiological and psychophysical responses to a range of pulse and sinusoidal stimuli. [Work supported by NIH.]
Application of the 4× real-time digital signal processor for the simulation of programmed sound environment: Aircraft/underwater noise simulation
Authors: Armand Jean-Pierre
Published: October 2005

Flight simulation and training programs for underwater detection and identification of ships require the synthesis of realistic sonic environments. The sound synthesis must be accurate, it must be linked to the simulation of motion and of the visual environment, and it must respond to changing internal and external conditions and to the actions of the pilot or operator. Analog sound synthesis techniques cannot meet these severe requirements. Therefore, we have applied the 4× digital sound processor, designed at I.R.C.A.M., to the synthesis of highly realistic aircraft and underwater noises. After analysis of the signals in various situations in frequency and time domains, an acoustical sound generation model is implemented in the processor. The parameters defining the sound characteristics being passed by the host simulation computer, are derived from a mechanical model of the planes or ships. For example, the aircraft noise comprises fan, propeller (if needed), jet, gear, aerodynamic sounds, as well as alarms and VHF traffic communications. The underwater noises consist of sea background, biological noise (shrimps), and one boat, the complex noise of the boat itself being made up of diesel engines, gear works, auxiliary equipment, and propeller noise, with various cavitation and blade configurations.
Auditory physiological properties of the units in the cerebellum of the FM bats, Eptesicus fuscus and Myotis lucifugus
Authors: Jen Philip H.-S. , Kamada Tsutomu , Sun Xinde
Published: October 2005

Response properties of cerebellar units in the FM bats, Eptesicus fuscus and Myotis lucifugus were studied under free-field and closed-system sound stimulation. Units responding to sound stimuli could be isolated from a rather large area of cerebellar vermis and the cerebellar hemispheres. Only a few units fired tonically while most discharged between one and five impulses during acoustic stimulation. Response latencies ranged between 2.97 and 68 ms with most between 8 and 14 ms. Threshold curves were broadly tuned with a triangular or irregular shape. Similar to units in the auditory nuclei, the number of impulses fired by cerebellar units changed either monotonically or non-monotonically with stimulus intensity. In the closed system study, the latency of an investigated unit to monaural stimulation was approximately the same as to binaural stimulation. Threshold curves of the same unit measured from each ear were also similar in shape and best frequency. Although all the units studied could be activated by stimuli delivered to either ear, the neural mechanism of binaural interaction is not a simple summation or occlusion. [Work supported by NSF BNS 80-07348 and USPH 1-K04-NS-00433-03 to P. Jen.]
Calibration of a dynamic pressure transducer using reciprocity in a plane-wave resonator
Authors: Swift G. W. , Migliori A. , Wheatley J. C. , Garrett S. L.
Published: October 2005

Using the principle of reciprocity in a plane-wave resonator we have obtained on accurate absolute calibration of a dynamic pressure transducer in 10-bar helium gas. The resonator consisted of a 365-cm-long, 7.3-cm-diam stainless steel tube with ordinary electrodynamic loudspeakers sealed to both ends. The transducer to be calibrated, mounted near one end of the resonator, was a silicon strain-gauge piezoresistive bridge with a nearly frequency-independent sensitivity from zero frequency through 400 Hz. We found that the reciprocity measurements agreed with a static calibration of the transducer using a mercury manometer to within 1%, consistent with instrumental uncertainties. [Work supported by the U.S. Department of Energy.]
Directivity pattern measurements of a transducer array in a highly reflective enclosure
Authors: Zets Gary A.
Published: October 2005

Underwater acoustic measurements are commonly made in laboratory test tanks because of the advantages offered by a controlled environment. Violations of some of the conditions assumed by theory often occur, making direct comparisons between measurement and theory impossible unless specialized techniques are utilized. In particular, directivity pattern measurements of highly directional transducers require good free-field and farfield conditions which are usually unattainable in a test tank. In this paper, directivity patterns of a directional array were measured in a highly reflective enclosure to determine the best agreement with theory under these severe conditions. For convenience, and without loss of generality, the experiment was conducted in air. A linear 11-element microphone array was constructed and tested in a reverberation chamber using a computer controlled, gated measurement system. The theoretical array directivity pattern was computed under both ideal and real conditions and comparisons showed that extremely good measurements can be made if the correct procedure is followed.
Resonance modes of an elongated chamber in the presence of a temperature gradient
Authors: Jacobi N. , Robey J. , Trinh E.
Published: October 2005

The Helmholtz equation was solved analytically for a step temperature profile, so as to describe measurements earlier reported [E. Trinh, T. O. Wang, and J. Robey, J. Acoust. Soc. Am. Suppl. I 70, S90 (1981)] for an elongated vertical chamber with a significant temperature gradient along its main axis. The solution is expressed in terms of trigonometric and/or hyperbolic functions, and a dispersion, or characteristic, equation is obtained for the resonance frequency of the compound system by imposing appropriate boundary conditions. It is found that the hot region sustains periodic, standing wave solutions in some cases, and exponentially decaying, evanescent wave solutions when the standing wave cannot propagate from the cold to the hot region. The characteristic equation is solved by numerical iterations, resulting in temperature-dependent pressure profiles and resonance frequencies which are in good qualitative agreement with experimental results. The frequency spectrum for a given temperature gradient is also computed by searching for the roots of the characteristic equation. The simple step model is extended to describe a gradual temperature change, and for a linear dependence the solutions are expressed in terms of Airy functions. [Work supported by NASA.]
Design of a traveling lens using acoustic solitons
Authors: Banerjee P. P. , Korpel A.
Published: October 2005

In an acoustic traveling wave lens device (ATWL) a high amplitude sound pulse acts to focus an incident light beam which tracks the moving pulse. By this method the resolution of acousto-optic beam deflectors may be increased by an order of magnitude. If a liquid medium is used for maximum effect, the power of the lens is limited by nonlinear behavior, which eventually leads to shock formation. In principle this may be avoided if the medium could be made dispersive such that the phase velocity would decrease with increasing frequency. In that case the pulse shape should remain constant due to a balance between nonlinear and dispersive effects. Such pulses are called solitons; they have, of late, been the subject of much research but, with the exception of optical solitons in fibers, have not been investigated in an applications context. In this communication we discuss a possible application of acoustic solitons. We first describe their properties relative to the nonlinear and dispersive parameters of the medium. We then propose a method of obtaining the necessary dispersion by making the rigid walls of a sound tank locally reacting through the use of thin plastic strips. [This research is sponsored in part by the National Science Foundation under Grant ♯ECS 8121781.]
Duration discrimination of noise bursts presented at a rapid rate
Authors: Shelton Brian R.
Published: October 2005

The influence of the presentation rate of two noise bursts on the discrimination of duration was assessed using an adaptive two-alternative, forced-choice procedure. The time difference required for reliable discrimination was determined for 70 dB SPL noise bursts of 25-, 50-, 100-, 200-, 400-, 800-, and 1600-ms duration. The interval between the presentation of the two noise bursts in each trial was set at either 50, 200, or 1600 ms. The Weber fraction, Δt/t, was determined by an interaction between the noise duration and the rate of presentation. With a presentation interval of 1600 ms, Δt/t was a constant of 0.08 at all noise durations. Presentation intervals of 50 and 200 ms produced Δt/t functions which were elevated for short noise durations, but converged on the 0.08 Δt/t performance level with noise duration of 1600 ms. The Δt/t for a 25-ms signal was 0.30 with a 50-ms presentation interval, and 0.22 with 200 ms between noise bursts. The results are discussed in relation to neural constraints on the timing of rapidly presented stimuli. [Work supported by NSERC.]
Specialty materials for underwater acoustics
Authors: Ting Robert Y.
Published: October 2005

In recent years, a majority of the failures of underwater transducers and sonar windows have been identified to be related to problems with the materials used in these systems. Most frequently, a design will successfully meet the initial performance requirement, but the device quickly fails after a short time of exposure to the service environment. The failure mechanisms often are attributable to the fact that the presently used materials are generally not optimized for long-term operation and always poorly characterized for their aging properties. In many cases, material components for a transducer may be selected from different sources, and this results in serious compatibility problems. Furthermore, because of the proprietary nature of many commercial materials, the user has very little control over the quality of the material, which often shows large batch-to-batch variations. This nonreproducibility has made it extremely difficult to properly repair or replace the failed acoustic devices. In order to increase the readiness of present sonars and to improve the lift-time performance requirement of future new transducers, it is necessary to understand materials' composition-property relationship, to develop quality control techniques and to design new materials for optimum applications. In this presentation, the major problem areas will be addressed, and progress made in both the acoustically active and passive materials will be discussed.
Interaction of interaural time and intensity
Authors: Yost William A.
Published: October 2005

The thresholds for interaural temporal and intensive differences were determined as a function of a variety of stimulus conditions. The thresholds were determined in a two-alternative, forced-choice task when the stimuli were presented with a constant interaural temporal or intensive difference. That is, the thresholds were measured in conditions in which the lateral image is moved off midline with the introduction of an interaural temporal or intensive difference. A random change in overall level prevented the listener from using monaural intensive or binaural loudness differences as cues for discrimination. The thresholds were measured as a function of signal frequency (200–1200 Hz) for 250-ms tones presented at 60 dB SPL. Both interaural temporal and intensive thresholds increased as the value of the constant interaural difference increased (images moved away from midline). The interaural temporal difference threshold changed from approximately 3° to approximately 18° as the constant interaural intensive difference increased from 0 to 15 dB. The interaural intensive threshold changed from approximately 1 to approximately 2.1 dB as the constant interaural temporal difference changed from 0° to 180°. The effects of frequency were small but significant. The results will be discussed in terms of the relationship between lateralization and localization of pure tones. [Work supported by The National Science Foundation.]
Experimental estimates of the energy partitioning in long-range, low-frequency seismic-acoustic propagation
Authors: Baggeroer A. B.
Published: October 2005

Several recent experiments have used arrays to resolve the multipath in long range, low-frequency seismic/acoustic propagation, These experiments have been conducted in several geologic environments including, (i) the thickly sedimented Canada Basin (CANBRAX); (ii) the abyssal plains of the Eastern Arctic (FRAM II and FRAM IV); and (iii) the young crust of the East Pacific (ROSE). In characterizing the seismic/acoustic propagation the array data are used to estimate slowness-travel time spectra. These are first transformed to a “τ-p” spectra and migrated to a velocity-depth spectra to estimate a crustal model. The slowness-travel time spectra are next used to measure the energy partitioning among the multipaths, or equivalently their scattering function, and their attenuation, or “Q” factors. Finally, they are used to estimate the boundary effects of the seabed upon the model energy to complete the analysis of the seismic/acoustic propagation. Each of the geologic environments generates very diverse multipath structure. The effects of bottom roughness, sediment thickness, and velocity gradients upon the crustal models, energy partitioning of the multipaths and the model energy will be illustrated using experimental results from the array data.
Shallow water infrasonics: Propagation and noise studies with ocean bottom seismometers
Authors: Rauch D. , Schmalfeldt B.
Published: October 2005

Sound propagation studies near or below the hydroacoustic cutoff frequency of shallow water ducts have been strongly neglected in the past. The growing interest in bottom-interacting phenomena stimulated the investigation of pertinent propagation mechanisms to identify low-frequency sources or to probe the upper sea floor in-situ. For this purpose three-component ocean bottom seismometers each with a radio link and an external hydrophone have been developed and deployed during several sea trials off the Italian coast near La Spezia. Numerous measurements from small underwater explosions and from the ambient background or passing ships were analyzed with various software packages. The results to be discussed in this paper are confined to the infrasonic regime from 1 to 18 Hz. Shot-data are illustrated by typical seismogram sections, particle hodographs, dispersion contours for amplitude or phase, and attenuation curves, while noise data are presented in the form of amplitude or cross spectra. It can be clearly demonstrated that the infrasonic energy is mainly transmitted via seismic interface waves of the Stoneley- or Scholte-type propagation along the sea floor.
Sound speed and attenuation in marine sediments measured at high frequencies with a bottom probe system
Authors: Igarashi Y. , Allman R. L.
Published: October 2005

The evaluation of many high-frequency bottom-interaction models requires as inputs sound speed and attenuation in marine sediment. A bottom probe system mounted on the underside of a cable-controlled underwater vehicle was used to make measurements at 15, 30, and 60 kHz, and at probe depth positions of 17, 42, and 67 cm. Sound-speed ratios are determined in-situ to 0.1% and attenuation to 0.2 dB/m. Measurements made in a 1 km by 1 km area of Puget Sound indicated small but significant spatial distributions of acoustic properties in a nominally uniform area. Attenuation coefficients were determined using the empirical relation K times frequency to the nth power. Exponent n was approximately 0.70. Past data in a Santa Barbara area indicated an n value of 1.19. These results indicate that for different sediments, exponent n is distributed about one with significant deviations. [Work supported by Naval Sea Systems Command.]
Dirac constraint treatment of surface waves
Authors: Uzes C. A.
Published: October 2005

Some of the commonly used boundary conditions on the displacement field of an elastic body are classified as Dirac constraints. The consequent equations of motion for the surface waves of the elastic body are constructed for a number of surface geometries and their possible applications discussed. [Work supported by ONR/ASEE Summer Faculty Research Program.]
Scattering of acoustic waves by submerged objects in the presence of a nearby boundary
Authors: Varadan V. V. , Varadan V. K. , Flax L.
Published: October 2005

The scattering of acoustic waves by objects submerged in water just above a rigid planar boundary is studied. The effect of multiple scattering between the planar boundary and the scatterer of general shape is completely accounted for. Our approach involves the use of the half-space Green's function with Neumann boundary conditions prescribed on the rigid planar boundary and the use of the T matrix of the single scatterer. Invoking the Helmholtz integral representation for the fluid half-space, the problem is changed to an equivalent scattering configuration which is equivalent to using the method of images. Frequency dependence and the angular variation of the sound field scattered by such a configuration is studied as a function of the shape and distance from the rigid boundary of the submerged object.
Four new scales based on nonsuccessive-integer-ratio chords
Authors: Mathews M. V. , Roberts L. A. , Pierce J. R.
Published: October 2005

Our previous work demonstrated that chords with frequency ratios 3:5:7: and 5:7:9: have many perceptual harmonic properties of major triads (4:5:6 ratios). The traditional diatonic scale can be constructed from three major chords, the tonic, the dominant, and the subdominant chords. Using analogous techniques with the new chords, we have constructed four new scales which we call the M579, M357a, M357b, and the P3579 scales. Pitches of the notes of these scales sound very different from the diatonic scale. All scales have clearly perceptable harmonic structure. All notes can be harmonized with consonant “major” chords. There are strong perceptual differences between consonant and dissonant chords. The M scales are based on an octave with a 2:1 frequency ratio. The P3579 scale has a 3:1 octave and was designed for timbres having only odd harmonics. In addition, P3579 is an equal tempered scale using a subset of 13 equal frequency divisions of the 3:1 octave. We believe these scales will be useful for nontraditional new music which has well defined and easily perceived harmonics. We also believe our techniques can be used to manufacture many additional scales.
The role of the acoustic reflex in modifying identification accuracy for vowels
Authors: Hannley Maureen , Dorman Michael F. , Lindholm Julie , Cedar Ingrid
Published: October 2005

“Rollover,” poorer word identification accuracy at high than at low SPLs, is correlated with the absence of the acoustic reflex in individuals with lesions to c.n. VII and c.n. VIII. The increased number of word identification errors at high SPL is due largely to errors in vowel identification. Individuals with these types of lesions, however, are rare. In order to study rollover in a normal population, we constructed 10 vowels of 50-ms duration. These were presented to normal hearing listeners at moderate and high SPLs. We reasoned that, since the latency to onset of the acoustic reflex, at the test levels, was longer than the total duration of the vowels, we should observe poorer vowel identification at the higher SPL than at the lower. This was, in fact, the outcome. Vowel confusions were usually with vowels with higher F2 and lower F1. This outcome was confirmed by the results of identification tests with stimuli along an /i/-/ε/ continuum.
Auditory nerve responses following middle-ear disarticulation in kittens
Authors: Walsh Edward J. , McGee JoAnn , Javel Eric
Published: October 2005

The effects of partial acoustic deprivation during postnatal development of kittens were studied following the disarticulation of their malleoincal joints. Disarticulations were performed between birth and 10 postnatal days. Prior to 10 postnatal days, auditory thresholds are in excess of 100 dB SPL, and it can be assumed that these animals receive little, if any, acoustic stimulation prior to surgery. Following surgical manipulation of their middle ears, kittens were allowed to grow to adulthood at which time single auditory nerve fibers were studied extracellularly, from both operated and intact sides. Threshold differences between the operated and intact sides confirmed that a conductive lesion had been produced. Other indices of neuronal function, however, showed that most of the fibers from the operated side were normal with respect to their tuning, dynamic range, and phase-locking ability. There was a slight tendency for fibers on the operated side to exhibit higher than normal spontaneous discharge rates, as well as slightly reduced tip-to-tail ratios. Most neurons had normal appearing tuning curves, however, some displayed shallow low-frequency slopes near their best frequency. In general, middle ear disarticulation did not produce profound effects on auditory nerve responses.
Changes in human regional cerebral blood flow in response to pure tones
Authors: Lauter Judith L. , Herscovitch Peter , Raichle Marcus E.
Published: October 2005

Last year we reported that changes in human cerebral blood flow, monitored with a positron emission tomography device (PET VI), could be demonstrated in response to auditory stimulation with synthetic syllables. Developments in image processing and schemes for anatomical localization have now made it possible to detect similar changes in response to pure tones. The topography of these changes seems to reflect: (a) ear of presentation, and (2) frequency of the stimulating tone. A number of presentation variables such as stimulus repetition rate affect the clarity of the response from individual to individual. Definition of these variables can help determine how best to proceed in our application of the PET scan to the study of human auditory perception.
Piezoelectric response in trifluoroethylene copolymers of vinylidene fluoride
Authors: Hicks J. C.
Published: October 2005

The copolymer system of polyvinylidene fluoride-trifluoroethylene, P(VDF-TrFe), has been shown to exhibit a Curie temperature Tc that is dependent upon the monomer ratio. Below this temperature the copolymer is in a ferroelectric phase similar to the stretched homopolymer, Polyvinylidene fluoride, PVDF. The piezoelectric response of this copolymer system for oriented, well-poled samples is very similar to and in some cases better than PVDF. Again the piezoelectric response may also depend upon the monomer ratio. However, when the copolymer with a monomer ratio of 3/1 for VDF/TrFE is poled above Tc and subsequently annealed it has an exceptionally high percentage crystallinity and an electromechanical coupling coefficient of 0.3. These values are for undrawn samples and can be used to predict a hydrostatic piezoelectric response approximately two to three times better than PVDF. These concepts and possible new data will be presented.
Pressure effects on the dynamic effective properties of perforated resonating elastomers
Authors: Gaunaurd G. , Callen E. , Barlow J.
Published: October 2005

We quantitatively analyze the effect of hydrostatic pressures on the static and dynamic effective material properties of perforated visoelastic elastomers. A resonance methodology that we had developed earlier [i.e., G. Gaunaurd and J. Barlow, J. Acoust. Soc. Am. 75, 23–34 (1984)] is here extended to account for the distorting effect of added pressures. The distortion basically produces a broadening of the spectral plots and a shift in the resonance peaks/dips that are observed in the dynamic plots of all the effective properties of the pertinent composites. For the lossy, air-filled rubberlike materials considered here the pressure effect is quite noticeable but smaller than the viscous effect or than the effect of nonuniformity in the cavity size-distribution functions that we analyzed earlier. The model is implemented by a computer code and its numerical predictions are quantitatively displayed for some of the most important of the effective material properties of a given perforated elastomer up to applied pressures of 400 psi. These perforated elastomers have uses as underwater sound absorbers. [Work partially supported by NOSC, San Diego, CA and by NSWC, White Oak, MD.]
Problems of the modern oboist that might be worthy of attack by acoustical engineers
Authors: Gainer Patrick A.
Published: October 2005

In its evolution through and beyond the shawm, the modern oboe has become, at least to some ears, a versatile instrument with a range of beautiful and expressive sounds. It has also become a very complicated instrument. Whereas the baroque oboe had 11 holes (or 13 if double holes count) and three keys, only two of which could be used, the modern oboe is drilled with at least 21 holes and a plethora of keys joined by linkages that would make Rube Goldberg happy. While the extra hardware and holes do make it easier to play in keys with lots of sharps and flats, they also cause problems. The oboe is not so close an approximation to the simple conical-bored reed instrument that it was in former days. Not only are there more holes, but the bore of the oboe has been made smaller over the years, and the walls thicker. Each tone hole is more like a tube. The placement, diameter, and amount of undercutting of the holes and the actual shaping of the bore seem to be an art rather than a science. Even two oboes from the same maker are likely to have significant differences that are left to the player for curing. Some of the deficiencies of the modern oboe, oboe d'amore, and English horn will be demonstrated along with some “home cures” used by performing oboists.
Current case law of the Occupational Safety and Health Review Commission
Authors: Rowland Robert A.
Published: October 2005

The current Occupational Safety and Health Review Commission precedent on the feasibility of engineering noise controls is Sun Ship, Inc., a 1982 decision. In that case Commissioners Cleary and Cottine reached a consensus on the meaning of the term “feasible,” on which they had not been able to agree earlier in Samson Paper Bag. Because Samson Paper Bag had not achieved a consensus on a new definition, the Commission there concluded that its original cost-benefit test (Continental Can) would remain in effect. Commissioners Cleary and Cottine now agreed to reject that test on the basis of the Supreme Court's 1981 decision in the “cotton dust case,” American Textile Manufacturers Institute, Inc., vs. Donovan (ATMI). The Court's decision, however, interprets and is predicted on a different provision of the Occupational safety and Health act than that under which the noise standard was promulgated. In a subsequent appellate decision, Castle & Cook Foods, the Ninth Circuit specifically concluded that the ATMI decision does not control the interpretation of the noise standard and that the Commission's previous cost-benefit test was reasonable.
The role of economics in compliance with the OSHA Noise Standard
Authors: de Bernardo Mark A.
Published: October 2005

The role that economic feasibility plays in employer compliance with (and OSHA enforcement of) health standards in general and the Noise standard in particular. Industries' problems with compliance with the Noise Standard and Hearing Conservation Amendment, particularly small business' problems. Preference for effective hearing conservation programs over government insistence of engineering controls. A comparison of the Reagan and Carter Administrations' Hearing Conservation Amendments. Industry objections to the current rule: (1) integration to 80 dBA; (2) inclusion of impulsive noise; (3) requirement of annual audiometric testing in all cases (instead of biennial or periodic); (4) qualification of the area sampling provision; and (5) general length and complexity (as unnecessary impediments to small business compliance). Support for OSHA compliance directive interpreting Castle & Cooke Foods, CPL 2-2.35. The cost-benefit issue in general, and the impact of the Supreme Court's 1981 cotton dust decision and Executive Order 12291 on cost-benefit analysis. Industry's position regarding further rule-making on the Noise Standard.
Application of the fiber optic lever in surface vibration and acoustic intensity measurements
Authors: Cook Reginald O.
Published: October 2005

Renewed interest in optic motion sensors has been prompted by the potential application of such techniques to surface vibration and acoustic intensity measurements. Optical sensors intrinsically possess one highly desirable attribute, that is, no loading of the structure, and possibly several others including high resolution and wide bandwidth. Of the available optic sensors, the fiber optic lever is perhaps the simplest practical approach. The characteristics of the fiber optic lever are such that the principal parameters, i.e, linear range, resolution, bandwidth, and working distance can be optimized to meet the constraints imposed by most surface vibration problems of interest. The key strategy in optimizing the lever is to obtain sufficient linear range to encompass low-frequency, high-amplitude vibrations while retaining sufficient resolution for small amplitude high-frequency motions. When sufficient reflected light is available to meet these requirements, wide bandwidth and excellent phase characteristics can be achieved by presently available electro-optic devices. The potential for a device permitting hand held “sweeps” of complicated noise radiators exists but is critically dependent on achieving extended linear range. The extent to which these requirements have been achieved in instruments optimized for acoustic intensity measurements close to the vibrating surface is described.
Mechanisms in auditory discrimination: Ontogeny and phylogeny
Authors: Sinnott Joan M.
Published: October 2005

Previously reported data indicates that human adults, human infants, monkeys, and birds can all be easily trained to discriminate frequency increments, frequency decrements, and intensity increments in a pulsed-tone stimulus using a repeating standard procedure and operant conditioning techniques. However, it is difficult, if not impossible, to train infants, monkeys, and birds to discriminate intensity decrements using the same methods, although human adults experience no difficulty with this task. An hypothesis to account for these results will be proposed: Discrimination of frequency increments, frequency decrements, and intensity increments implies a coding mechanism based on detecting rate increases in populations of peripheral auditory neurons, but discrimination of intensity decrements implies a mechanism based on detecting rate decreases. Therefore, the CNSs of human infants, monkeys, and birds may not be well adapted to monitoring rate decreases in peripheral auditory neurons. [Supported by Deafness Research Foundation.]
Relationships between articulatory and acoustic measurements from an x-ray microbeam study of variability in the production of the vowels /i/ and /a/
Authors: Perkell J. S. , Nelson W. L.
Published: October 2005

We have reported previously that midsagittal distributions of points on the dorsal tongue surface for multiple repetitions of the vowels /i/ and /a/ show more variation along a direction parallel to the vocal tract midline than perpendicular to the midline. This finding was interpreted as support for a hypothesis based on articulatory-to-acoustic modeling: the programming of movements towards the vowel targets is sensitive to non-linear relationships between articulatory displacements and formants [J. S. Perkell and W. L. Nelson in Speech Motor Control, edited by S. Grillner, A. Persson, B. Lindblom, and J. Lubker (Pergamon, New York, 1982)]. Statistics on formant values for one subject have been calculated, and pairwise regressions of displacement and formant data have been run. An articulatory synthesizer [P. Rubin, T. Baer, and P. Mermelstein, J. Acoust. Soc. Am. 70, 321–328 (1981)] has been manipulated through displacements similar to the subject's articulatory variation. The range of formant variation for the subject is comparable to the range of formant values produced by the synthesizer. However, there were only very weak correlations between the subject's articulatory displacements and his formant data. Possible reasons for the lack of correlations will be discussed. [Work supported in part by NIH Grant No. NS04332.]
Temporal organization of muscle activity in simple disyllables
Authors: Gentil Michèle , Harris Katherine S. , Horiguchi Satoshi , Honda Kiyoshi
Published: October 2005

In an earlier paper, Tuller and her associates have shown that the onsets of consonant and vowel related activity in several articulatory muscles tend to maintain a constant relationship over changes in stress and speaking rate [Tuller et al., J. Exp. Psychol. Percept. Perf. 8, 460–472 (1982)]. Similar results are found for analogous kinematic events [Tuller et al., J. Exp. Psychol. Percept. Perf. 9, 829–833 (1983)]. The present study confirms and extends the results of the original electromyographic study, for a speaker of a different language (French rather than English), for a somewhat extended consonant and vowel inventory /p VC p a p/, where V = /i, a, or u/, and C = /p, t, s/; and for a somewhat broader range of muscles, five associated with tongue movement, and two others associated with lip and jaw movements. The constancy of the relative timing is compatible with a model of speech production in with coordinative structures are specified. [Research supported by NINCDS.]
Contribution of mandible movement to lower lip and tongue blade movements
Authors: Edwards Jan , Fujimura O.
Published: October 2005

Apparent violations of the sequential organization of phonetic gestures in the observed time series of constrictive positions were reported by Fujimura [Phonetica (1980)]. Using data collected by the x-ray microbeam system [Kiritani et al., J. Acoust. Soc. Am. (1975)], we have found that the temporal structure of lip and tongue blade movement patterns can be interpreted more straightforwardly if the jaw component of lip and tongue blade movements is subtracted. Previously observed violations of segmental sequencing are largely interpretable as the superposition of mandible gestures onto lip or tongue blade gestures. This suggests that apparent complexities and variabilities of the observed movement patterns may be reduced by distinguishing between stress-related syllabic gestures and place-related consonantal gestures. Different functions assigned to the articulators can be implemented via articulatory subsystems with different dynamic characteristics. This implies that in speech perception the interpretation of acoustic signals involves the undoing of these temporal complications in order to identify the “correct” sequential patterns. Supported in part by NINCDS.]
Asymmetries in placement and timing of alveolar tongue contact patterns for /s/ and /l/
Authors: Hamlet Sandra L. , Bunnell T.
Published: October 2005

The “central groove” of the tongue for /s/, and the alveolar tongue contact pattern of /l/ frequently show left-right asymmetries. These articulatory asymmetries are highly consistent within an individual, but do not seem to bear a clear relationship to other type of sidedness, such as hand preference. Left-right differences in alveolar and palatal contour have been suggested as a causal factor. The present study employed dynamic palatography with five subjects. Tongue contact for /s/ was initiated earlier on one side, as if to anchor the tongue. Subsequently, a more anterior groove formation followed. Contact and release in a VCV environment were similar, with the side touched first at onset of /s/ being the side to be released later. The side with greater (and usually earlier) contact for /s/ was generally also more widely contacted for /l/, such that the lateral margin of the tongue appeared at times to be free only on one side. Since sidedness was similar for /s/ and /l/, /sl/ blend articulation was simplified. Preliminary results of an experiment in altering the oral contour with a dental appliance, thicker on one side, and the resulting palatographic changes will also be discussed. [Work supported by NIDR.]
Possible effects of snow layer absorption on under ice reflectivity
Authors: Diachok Orest , Wales Stephen , Ngoc Tran
Published: October 2005

Sea ice, which consists of relatively flat plates (nominally 2.5-m thick), randomly interrupted by ridges (rubble piles of broken ice), is generally coverged by a thin layer (nominally 0.2 m) of snow. The reflection coefficient from snow-covered sea ice plates, computed with the FFP, reveals generally large losses at frequencies higher than 100 Hz and grazing angles greater than 10°. Losses are maximum for frequency-angle combinations that permit conversion to Lamb modes in the ice plate. Loss magnitudes are particularly sensitive to the snow layer absorption coefficient. Computed results are consistent with reflectivity versus frequency and grazing angle (Θ > 14.3°) measurements reported by Yang and Votaw [J. Acoust. Soc. Am. (1981)], assuming their estimates of plate thickness and historical ice and snow velocity, density, and absorptivity data. At grazing angles less than 10° computations suggest that snow effects on the reflection coefficient are small, a result which is consistent with the hypothesis that long-range under-ice propagation loss is dominated by ridges [Diachok, J. Acoust. Soc. Am. (1976).]
Studies on acoustical field of vibrating pistons
Authors: Jiang J. K. , Prasad M. G.
Published: October 2005

Studies on acoustic radiation from vibrating structures is of importance in machinery noise control. This paper reports studies on both the acoustical near and farfields of vibrating pistons. The boundary integral equation (BIE) method based on the Helmholtz integral formulation has been used. Three types of pistons are investigated: (1) a circular piston in an infinite baffle (baffled piston), (2) a circular piston at one end of a semi-infinite rigid pipe (enclosed piston), and (3) a finite thickness piston in space (free piston). The studies are aimed at investigating the boundary effects of the baffle, effect of the piston thickness, and directivity patterns in both acoustical near and farfields. The results from the BIE method are compared with the available classical results such as from the Rayleigh integral. The comparison of the results for the case of the baffled piston is very good in both near and farfield. It is intended that this method will be useful in investigating the acoustical fields of vibrating structures including the boundary effects. [Work supported by IBM Corporation, Pough-keepsie, New York.]
Noise transmission loss of a rectangular plate in an infinite baffle
Authors: Roussos Louis A.
Published: October 2005

An improved analytical procedure has been developed that allows for an efficient solution of the finite plate noise transmission problem. The plate is modeled with classical thin plate theory and is assumed to be simply supported on all four sides. The incident acoustic pressure is modeled as a plane wave impinging on the plate at an arbitrary angle of incidence. Assuming the radiation damping is negligible compared to the structural damping, the incident, reflected, and transmitted pressures are approximated by the blocked pressure which allows the plate vibrations to be calculated by a normal-mode approach. A Green's function integral equation is used to link the plate vibrations to the transmitted farfield sound waves. The incident and transmitted acoustic powers are calculated by integrating the incident and transmitted intensities over their appropriate areas, and transmission loss is calculated from the ratio of incident to transmitted acoustic powers. The result is a versatile research and engineering analysis tool that not only enables the determination of which modes are dominating the noise transmission, but also allows for the problem to be broken down into its composite parts. This includes determining what the modal behavior is, such as, coupling between the incident noise and the plate vibrations; the plate resonance behavior; and the coupling between the plate vibrations and the transmitted noise. The effect of varying the angle of incidence and the farfield directivity can also be determined from the analytical model. The analysis approach was developed to study propeller noise transmission into aircraft and is seen to be equally applicable to sound transmission through building walls, floors, and windows.
Sound intensity techniques for identifying locations of scale model jet noise sources
Authors: Roth David J.
Published: October 2005

Experimental investigations were made to identify the physical source locations of a 6-in. equivalent diameter scale model coaxial jet using two-microphone sound intensity measurement techniques. Near and farfield measurements were made within a large volume anechoic chamber in two directions from the jet centerline. The jet was operated under conditions of hot and cold flow at several nozzle pressure ratios. The data were recorded on magnetic tape and narrow-band analyzed to identify the direction of the intensity vector from the centerline of the jet to the location of measurement. The analysis method consisted of converting the value of imaginary cross spectrum to intensity vector along a microphone line. The resultant vector was then calculated and extrapolated back to an estimated jet axis flow boundary. The source locations identified for the model jet were verified by a loudspeaker source and were in good agreement with SAE jet noise prediction models. The measurement method used was subject to some error due to dropout of intensity vector perpendicular to the radial in the farfield. An alternate two-microphone probe technique is suggested that may overcome this problem.