bluuebunny/crossref_metadata_2025 huggingface dataset:
Two bar forced choice positive reinforcement training technique for psychoacoustic experiments in the chinchilla
Authors: Merwin G. E. , Kiester Thomas E.
Published: October 2005

Subjects were four chinchilla culls maintained at 80% of free feeding weight. All training and testing were carried out using a minicomputer. Animals were trained to initiate a trial by completing a fixed ratio of bar presses on a combination response lever and food hopper (hopper response) during an SD period. A hopper response is followed by a 5-s period during which either a stimulus tone or no tone is presented. This period ends as two retractable response levers are allowed to enter the chamber on either side of the hopper. Bar press responses to the “tone” or “no tone” bar appropriate to the stimulus conditions (tone hits and correct rejections) are reinforced by food pellets. Response errors (misses and false alarms) are followed by a 10-s time out from reinforcement with cage lights out. Training continued until stabilization of discrimination behavior at suprathreshold levels was obtained. Animals trained by this technique were suitable for developing psychoacoustic functions using both the method of constant stimuli and the method of limits. Psychoacoustic functions are presented.
Target recognition via echolocation by an Atlantic bottlenose porpoise (Tursiops truncatus)
Authors: Hammer Clifford , Au Whitlow W. L.
Published: October 2005

This study investigated the target-recognition behavior of Tursiops truncatus as a function of target composition and internal structure. Cylindrical targets were presented at ranges of 6 or 16 m. Near errorless differential reporting was established using hollow aluminum and solid coral rock targets, and this behavioral baseline was then used to investigate the differential reporting of other targets varying in structure and composition. The results of experiment I suggested that the critical characteristic for differentially reporting the baseline targets was located in the aluminum targets and not in the coral rock targets. The diameter and wall thickness of the aluminum targets also helped to characterize them. Experiment II showed that aluminum targets with walls differing by as little as 16 in. could be differentiated from the standards. Experiment III suggested that given targets of the same size and wall thickness, the critical characteristic found in the aluminum targets was recognized in glass more often than in bronze and least of all in steel. Results of echolocation signal measurements were consistent with the animal's behavior and performance.
Analysis of target recognition via echolocation by an Atlantic bottlenose porpoise (Tursiops truncatus)
Authors: Au Whitlow W. L. , Hammer Clifford
Published: October 2005

The targets used in the “Target recognition via echolocation by an Atlantic bottlenose porpoise (Tursiops truncatus)” study were acoustically examined in order to determine the salient features of the targets that would allow the animal to recognize and differentiate between the different targets. The echoes from the targets were obtained by using a broadband dolphinlike echolocation signal that had a similar waveform, peak frequency, and bandwidth with measured echolocation signals. The waveshape, frequency spectrum, target impulse response, and the matched-filter response of the echoes were analyzed to determine features of the echoes that could be used by the animal to discriminate between targets. The echoes usually consisted of the major specular reflection for the front of the target followed by echoes of progressively diminishing amplitudes for the exterior of the target. The first two echo components, from the front face and interior boundary of the rear face, had the predominant influence of the shape of the spectrum. The results of the matched-filter analysis showed a close correspondence with the animal's performance.
A model for the bat versus moth pursuit-evasion problem
Authors: Anderson G. M.
Published: October 2005

An area of research interest in the bat versus moth problem is to determine the type and accuracy of information on the moth's maneuvers that is available to the bat through its sonar tracking system. A possible approach to the solution of this problem is to determine the optimal maneuvers of the bat and the moth assuming perfect information is available to both participants. Comparisons of these maneuvers with actual maneuvers may provide insight into the type and accuracy of the information available to the bat. This paper models the bat versus moth problem as a zero-sum perfect information differential game which will simulate these optimal maneuvers. The moth is assumed to have constant slow speed, but can instantaneously change its velocity direction. The bat has a higher constant speed with some minimum radius of turn. The goal of the bat is to capture the moth in minimum time and that of the moth is to maximize this quantity, i.e., to escape. Results show that the bat can always capture the moth if he has perfect information. There is, however, a critical distance between the two players where a sudden sideways maneuver by the moth will result in escape if the bat does not react rapidly enough.
Purely by coincidence
Authors: Corliss Edith L. R.
Published: October 2005

Several conceptually different models for the behavior of the ear yield identical equations. One mechanism yielding the relationships observed—which are borne out by experimental data—is “coincidence counting” presumed to take place at neural synapses. This mechanism seems particularly suited to natural systems made up of many small components, all essentially alike. A number of other mechanisms that have been postulated are also inherently coincidence counters. Thus, as in the title, the ear may work by coincidence, or it may be a coincidence that equations so derived describe the phenomena observed.
Computer analysis of relative lung volume and air expenditure during speech
Authors: Maki J. E. , Mershon S. , Conklin J. M.
Published: October 2005

Through the use of electromagnetic transducers, movement of the chest wall can be measured and used to analyze lung volume and air expenditure characteristics of the speaker. In order to insure measurement accuracy and facilitate analysis, a Nicolet Med-80 Signal Processing Computer was used. This paper reports on the computer techniques used in extracting and analyzing respiratory data to obtain air expenditure and lung volume measurements. To verify these measurements, two phaselock generators were used to simulate calibration data needed for analysis. To simulate respiratory data, the voltage of a signal was varied during the data collection procedure. With respect to respiratory data, the rollage values corresponded to relative lung volume measurements, and the difference between any two values corresponded to volume change. Inspection of data displays plus comparison of the voltage readings with corresponding values from the computer showed that the computer provided accurate measurements of relative lung volume and volume change. Application of the computer analysis will be demonstrated using data from this study, plus actual respiratory data from two subjects who demonstrated significant differences in air expenditure and lung volume characteristics. [Supported by HEW.]
Larynx height and voicing
Authors: Riordan Carol
Published: October 2005

Many studies argue that larynx lowering would effectively maintain the transglottal airflow necessary for voicing to continue during stop closure. The empirical support for this hypothesis is primarily the tendency of the larynx to be lower for voiced than for voiceless stops. Earlier discussions, however, frequently do not state that a larynx height difference affects glottal airflow only if it implies an increase in supraglottal volume during closure. To investigate larynx movement during closure and how it relates to oral pressure build-up, larynx height and intraoral pressure were monitored while subjects produced intervocalic bilabial stops. The results are damaging to the hypothesis that speakers regularly lower the larynx during voiced stops to reduce the pressure-equalizing effect of oral closure. Although differences in larynx height between voiced and voiceless stops were observed, there were no consistent differences in the magnitude or frequency of larynx lowering during closure between the stop categories. Further, the larynx lowered during nasal stops, although nasal airflow presumably maintains transglottal airflow without cavity-enlarging maneuvers. Finally, there was no unique relationship between paired larynx height/pressure values for the voiced stop as might be predicted. [Work supported by NSF and NIH.]
Laryngeal muscle activities in relation to glottal shape in voiceless sound production
Authors: Sawashima M. , Hirose H. , Yoshioka H.
Published: October 2005

Simultaneous EMG recording of the laryngeal abductor (PCA) and adductor (INT) muscles with laryngeal filming by use of a fiberscope was made with two subjects during utterances of various voiceless sounds and sound sequences in Japanese words in a frame sentence. For each of the utterance samples, the activity patterns of the two muscles were observed in correspondence with the opening and closing movements of the glottis. There was a reciprocal pattern of activity between the two muscles in relation to glottal abduction and adduction during speech, this finding being consistent with previous reports. There was, however, a difference between the subjects in that the time course of the glottal movements was predominantly controlled by the PCA in one subject, while the INT as well as the PCA appeared to actively control the glottal condition in the other subject. [Work supported by Ministry of Education Grant-in-Aid for Scientific Research, No. 239005.]
On the added mass matrix and acoustic pressure of multiple circular cylinders vibrating in a compressible fluid
Authors: Lin W. H. , Chen S. S.
Published: October 2005

The linear two-dimensional acoustic wave equation is solved for multiple circular cylinders vibrating harmonically in an infinite compressible fluid. The solution is expressed in terms of series of cylindrical wave functions. To satisfy the interface boundary condition of a particular cylinder, all cylindrical wave functions are transformed to the coordinates associated with that cylinder. The resulting equations are a system of algebraic equations for the undetermined coefficients, which are solved numerically by digital computer. The velocity potential, pressure, and force acting in each cylinder are then obtained in terms of these coefficients. The added mass matrix is found symmetrical and dependent on the wave number, the cylinder radius, and the distance and orientation between cylinders. On the surface of each cylinder the pressure field also depends on those parameters as well as the orientation of point on that surface. Numerical values of added mass matrix and pressure distribution are obtained for many cases.
Realization of the transfer function of a loudspeaker by optimization method
Authors: Yoneyama M. , Fujimoto J.
Published: October 2005

The purpose of this research is the synthesis of the transfer function of a loudspeaker. The characterization of a loudspeaker as a linear system is represented by its impulse response. It is assumed that the waveform of the impulse response is approximated by the summation of many different decaying cosine waves having four parameters (amplitudes, decay factors, frequencies, and phases). To minimize the root-mean-square error between the measured impulse response and the composed one, all parameters should be determined by computer optimization method. For the computer optimization method, Hooke-Jeeves' method (one of the direct search methods) was adopted. By operating with a Laplace transform on the composed impulse response, it is possible to obtain the transfer function as the summation of function of the second-order. From the computed transfer function, pole-zero configuration can be obtained. As a result of our experiments using a loudspeaker with edge clamped circular radiating plate, the configuration of 28 poles and 27 zeroes was determined.
A proposal of a method to evaluate the electrostrictive material for ultrasonic transducers
Authors: Banno H. , Sobue H.
Published: October 2005

The electrostrictive ultrasonic transducers operate under both high mechanical amplitude of vibration and high electric field. So far it has been measured either electrically or mechanically to evaluate electrostrictive materials for the ultrasonic transducers. Both methods cannot possibly justify their full legitimacy, because each does not always represent the actual use of material. We propose applying a new evaluating method of electrostrictive materials for ultrasonic transducers. This introduces the figure of merit A2/r1G1, involving both electrical and mechanical terms [where A is the force factor, r1 the mechanical internal resistance, and G1 the blocked conductance]. The figure of merit depending on the vibration velocity is described for several electrostrictive materials.
Effect of single-motor-unit firings on fundamental frequency of phonation
Authors: Baer Thomas
Published: October 2005

A technique originally used for studying contraction properties of skeletal muscles was applied to study of the musculature controlling fundamental frequency (F0). Continuous records of electromyographic activity from laryngeal muscles and of voice fundamental frequency were obtained from a subject producing steady, sustained phonation at low F0. The fundamental frequency record exhibits small perturbations around a nominally constant value. An average-response computation of fundamental frequency triggered by single firings in the cricothyroid muscle exhibits a systematic pulse in the interval immediately following the firings. The pulse apparently represents the average effect on F0 of a single twitch in the muscle. This result implicates variability of motor input as a contributing factor in F0 perturbation. The same technique can be used to investigate the effect of other muscles on F0. Using this technique, muscles whose activity is grossly intercorrelated during ongoing F0 control can be uncorrelated to examine their individual effects on F0. Implications for detailed models of fundamental frequency control will be discussed. [Work supported by NINCDS grant NS 13870.]
Observation of vocal fold vibration by x-ray stroboscopy
Authors: Saito Shigeji , Fukuda Hiroyuki , Ono Hiroshi , Isogai Yutaka
Published: October 2005

Every laryngologist wants to observe the vibratory pattern of the vocal cords from all directions. A pulse generated x-ray equipment has recently been widely used as part of diagnostic procedure especially for cardiovascular lesions. Voice-synchronized x-rays can be obtained by use of a pulse signal from a laryngostroboscope as a trigger to this x-ray equipment. An experimental sound was obtained by use of the resected larynx of a human and a cannine. As contrasting mediae, lead particles were inserted into the vocal cord itself. Therefore, the vibratory pattern of the upper and lower surfaces of the vocal cords, and in addition, the vibratory movements under the epithelium could be simultaneously demonstrated on a videoscope while being photographed using a 35-mm fluoro-cinematograph. In addition, this method was applied to the study of the effects of various laryngeal lesions. The vibratory patterns obtained were compared to ones obtained by conventional laryngostroboscopy and discussed from the viewpoint of phonodynamics.
A voice analysis system using a digital processor during phonosurgery and its clinical application
Authors: Oho Hiroshi , Saito Shigeji , Fukuda Hiroyuki , Ichikawa Tadashi
Published: October 2005

In microsurgery of the larynx we have employed a laryngostroboscope by which the pattern of vocal cord vibration can be observed. Neuroleptoanalgesia is also performed during these operations to allow the patient to phonate. Immediately after such operations, an almost normal vibratory pattern of the vocal cords is obtained and normal voice is firmly restored. Therefore, we designed a sound monitoring system for the phonetic and acoustic analysis of the patients voice. This system consists of an online realtime data processor, fundamental frequency extractor, and data recording device. The sound wave, pitch variation, pitch histogram, and sound wave regularity are obtained by use of specially designed programs for this system. In addition, these data are printed by a digital printer. After application of this method to more than 100 cases with various laryngeal lesions, it was concluded that this method is very helpful in clinical use.
Evaluation of a rectangular ultrasonic transducer for laryngeal use
Authors: Hamlet S. L.
Published: October 2005

In past ultrasonic work a pair of circular unfocused transducers have been used in our lab for through-transmission studies of vocal fold vibration. Each produced a beam width at the laryngeal midline of about 6 mm. Two problems in studying vocal fold activity have been encountered. Because the larynx moves up and down in the neck during speech, over an extended utterance such as a sentence the vocal folds are pulled in and out of the ultrasonic field. On the other hand, lateral resolution was too gross for such applications as tracking the superior and inferior portions of the vocal folds during phonation. An attempt was made to improve performance relative to both of those problems in a single transducer design. A rectangular element has been placed in the transmitting transducer, which produces a calculated eliptical field approximately 2 × 8 mm at the laryngeal midline. The receiving element is square. Physiological evaluation of this new transducer combination is reported relative to tracking the upper and lower portions of the vocal folds independently, and (with the field oriented with the long axis vertically) the ability to receive an ultrasonic signal through the vocal folds throughout an utterance. [Work supported by NIH grant DE-03631.]
Spectrographic evidence for uniformity of voicing in obstruent clusters
Authors: Janda R. D.
Published: October 2005

It is regarded as a near universal that obstruent clusters are, phonetically, of uniform voicing [Chomsky, N. and Halle, M., The Sound Pattern of English (Harper and Row, New York, 1968)], Nevertheless, there putatively exists a large class of counterexamples, in many languages, involving [v]. Thus, phonetic transcriptions uniformly show, e.g., German zwei “two” and Schwein “pig” as, respectively, [tsvai] and [švain]; Russian tvoy “your” and svoboda “freedom” as beginning with, respectively, [tv] and [sv]; English svelte as [svɛlt], etc. However, preliminary spectrographic results from English indicate that what has been transcribed as (voiced) [v] in such cases is, in fact, (voiceless) [f]: The labiodental fricative in question is no more voiced than, e.g., the [p] in spin. Results will be presented of a larger study in which native speakers of English, German, and Russian read randomized lists containing words from their languages with tautosyllabic clusters customarily transcribed as Obstruent-[v]. [Work supported by NSF.]
An acoustic study of palatalization of fricatives in American English
Authors: Shattuck-Hufnagel Stefanie , Zue Victor W. , Bernstein Jared
Published: October 2005

The alveolar fricative consonants (/s,z/) are sometimes palatalized when they appear adjacent to a palatal consonant (/š,ž,y/) as, for instance, in “this ship” or “us yet.” Two questions about this process were studied for six speakers recorded during both spontaneous conversation and sentence reading: (1) When do these palatalizable sequences merge toward a single phonetic unit? and (2) How similar are the resulting merged sounds to the corresponding English palatal segments (/š,ž/)? Both duration and spectral measurements were made. Preliminary results indicate that an alveolar fricative palatalizes more frequently and more completely when it is followed by a palatal fricative than when it is preceded by one. In addition, some palatalizable sequences merge toward the form of a palatal segment, but others merge into acoustic forms which do not correspond to any English segment. Detailed analyses of temporal and spectral characteristics can be used to evaluate alternative accounts of palatalization in terms of, e.g., deletion, gemmination, and/or anticipatory coarticulation.
Some experiments on anticipatory coarticulation
Authors: Bell-Berti F. , Harris K. S. , Tuller B. , Baer T. , D' Antonio L.
Published: October 2005

EMG data from studies of lip rounding and jaw lowering activity reveal that, for a given speaking rate and stress pattern, the onset of EMG activity associated with these gestures occurs at a time before vowel onset which is unaffected by the acoustic duration or the number of consonants in the preceding string. The apparent contradiction between these conclusions and those of previous studies of anticipatory coarticulation may arise at least in part from neglect of the effects of clustering on consonant duration. [Supported by NINCDS grants to the Haskins Laboratories.]
Acoustic correlates of stress in K'ekchi
Authors: Berinstein Ava
Published: October 2005

At the last meeting of the ASA it was shown that speakers of different languages have different biases with respect to the location of stress in a string of syllables of equal duration [A. Berinstein, J. Acoust. Soc. Am. 63, S55A (1978)]. English speakers had a bias to locate stress on an initial syllable, K'ekchi a final syllable, while Spanish had no syllable bias. When the length of syllables was systematically varied it was possible to overcome the effect of the bias in English and obtain judgments which equated length with stress. This was clearly not the case for K'ekchi. The investigation has proceeded to establish the acoustic correlates of stress in K'ekchi by comparing stressed and unstressed syllables in a corpus of field recordings controlled for vowel quality, phonemic vowel length, and word length. Intensity, pitch, and duration have been measured and particular attention paid to the inter-relationship of word final lengthening, phonemic length, and duration as a cue for stress. [Work supported by NIH.]
Quantitative measurements of euphausiids using a 120 kHz sounder
Authors: Sameoto D. D.
Published: October 2005

The biomass and density of euphausiids were estimated using a 120 kHz sounder during two years in the Gulf of St. Lawrence. Biological samples were collected simultaneously with the acoustic data with two types of multiple opening and closing nets during the two years. The correlations for biomass and density estimates between the acoustic and biological data ranges from 0.391 to 0.791. The acoustic data showed that a high percentage of the euphausiids avoided the MOCNESS type sampler during the day. A comparison of the relationship between biological and acoustic data for the two years showed that the second multiple net sampler, called the BIONESS, was much more efficient at capturing euphausiids during both the day and night. Estimates of the target strength of the euphausiids from the acoustic and biological data showed it to be lower than expected if the animals were in a horizontal position. Photographs taken from the BIONESS of the euphausiids in the acoustic scattering layers at the same time as the samples were taken showed most of the animals were not in a horizontal position.
Source level and bistatic target strength of the humpback whale(Megaptera Novaeangliae) measured from an oceanographic aircraft
Authors: Levenson C.
Published: October 2005

Sounds produced and reflected by humpback whales (Megaptera Novaeangliae) have been recorded from a colinear sonobuoy array deployed by an oceanographic aircraft. Source levels, target strengths, and frequency characteristics were analyzed utilizing a PDP-11. Time domain data were converted by direct Fourier transform and auto-power spectra were computed from results. Time domain arrival times at various sonobuoys were computed to accuracies greater than 20 ms and position of active and passive whale sources was determined by simultaneously solving explicit hyperbolic equations for origin of sound.
Lung resonance characteristics of submerged mammals
Authors: Duykers L. R. B. , Percy J. L.
Published: October 2005

Tests were conducted at TRANSDEC and other N.O.S.C. facilities to investigate resonance characteristics of lung cavities of various mammal species including humans, dolphins, and domestic swine. The subjects were either totally submerged or had their heads out of the water to allow breathing. Depending on these two positions, total lung resonance was observed to behave as a resonating sphere or as a Helmholtz resonator, respectively. Three specific frequency regions were investigated, i.e., low frequencies (below 100 Hz), medium frequencies (between 3 and 7 kHz), and high frequencies (between 50 and 100 kHz). The results compare favorably with theoretical calculations.
Session KK. Education in Acoustics: Panel Discussion
Authors: Tichy Jiri , Yasuda Tsutomu
Published: October 2005

With the increased need for persons with specialized education in Acoustics, it is timely to discuss a variety of problems related to education. The educators, representatives of the industry, research, consulting and other areas of acoustic employment will have the opportunity to exchange ideas related to education. First, the panelists will make an assessment of the current status of Education in Acoustics including the available education on both undergraduate and graduate levels. The availability of instructional materials including books, experiments and other media for instruction will be discussed. In order to assess the need for the various levels and depth of education, the manpower need and the market place for the graduates will be analyzed. Another area of problems will be related to projection of future requirements. Details of the needs and kind of education for academic teaching and research, technological developments and occupational careers will be debated. Also, the relation and function of the professional societies in the educational process will be analyzed.
Electroacoustic systems in multipurpose auditoria in Japan
Authors: Nagata M.
Published: October 2005

The function and the performance of electro-acoustic system have a great effect on the multiple way of use of an auditorium. Up to several years ago, their plans and designs were mostly conducted under contractor's side. But as their scales grow larger, and have a significant influence upon the performance of an auditorium, there rises such recognition that the electroacoustic system should be planned and designed as a part of acoustic design of an auditorium. However, their designing system is not fixed yet, as compared with room acoustic design and noise control. Recently, a study group was made up by the cooperation of acoustic engineers, consultants, and contractors, and several studies have started on the standardization of the facilities, performance specifications, loudspeaker requirements, and test program, etc. This paper describes these studies and investigations as well as the plans and the performance of the electro-acoustic systems in multi-purpose auditoria in Japan.
Transformerless designs of broadband ultrasonic transducer equalizers
Authors: Andersen J. , Augustine L.
Published: October 2005

A promising new equalizer design for broadbanding ultrasonic transducers was recently presented [J. Andersen and L. Wilkens, Ultrasonics Symp. (1977)]. The design matches a resistive source to a piezoelectric transducer with power gain displaying a maximally flat (Butterworth) characteristic. Unfortunately, two undesirable restrictions are part of the existing algorithm: (i) The center frequency of the design is fixed, limiting the usage of the technique to certain passbands, and (ii) the design either requires a sacrifice in gain or is unrealizable without the use of an ideal transformer for certain source resistance and transducer combinations. The purpose of this paper is to present a generalization of the algorithm which broadens the applicability of the technique. The main result is an algorithm for the design of a lossless transformerless broadband equalizer with optimum power gain for a variety of ultrasonic transducers from which the exact latitude on passbands and source resistances is completely delineated. [Work supported by NIH.]
Auditory filter characteristics inferred from simultaneous masking: effects of procedural variables
Authors: Margolis R. H. , Popelka G. R.
Published: October 2005

In a previous experiment [R. H. Margolis and A. M. Small, J. Speech Hearing Res. 18, 571–587 (1975)] the characteristics of the auditory filter were investigated by measuring the detectability (d′) of a long duration (250 msec) tonal signal as a function of the cutoff frequency of a continuous, low-pass, computer-synthesized, noise masker. In the present research, two experiments were conducted to explore the effects of certain procedural variables on the characteristics of the auditory filter inferred from low-pass masking data. In experiment I auditory filter characteristics were found to be critically dependent upon the range over which d′ is allowed to vary. Baseline detectability and the procedure for computing d′ from P(C) were found to be critical variables. In experiment II the effect of a pulsed versus continuous masker was explored. The signal was a 500-msec tone with a rise-fall time of 25 msec. The masker was gated identically to the tone or left on continuously. Tonal signals were slightly more detectable in the pulsed masker condition. The results of these experiments have led to the design of a notch-noise, pulsed-masking experiment for the investigation of auditory filter characteristics in normal and pathological ears. [Work supported by NIH and the Deafness Research Foundation.]
Aural difference tone masking in normal and hearing-impaired subjects
Authors: Komovic J. K. , Bilger R. C.
Published: October 2005

A remote-masking paradigm was employed to assess the ability of the cochlea to generate aural difference tones in four normal-hearing subjects, two “clinically-normal” subjects, and 17 subjects with sensorineural losses of various etiologies. The hearing-impaired subjects had one of three different patterns of hearing loss. Stimuli were three, A. M. complexes composed of the fourth, fifth, and sixth harmonics of three different fundamentals. All hearing-impaired subjects had abnormal masking patterns at one or both masker levels regardless of complex or modulation depth. Moreover. the individual differences in processing ability (masking) were not predicted by pure-tone thresholds. These results demonstrated that identification of cochlear site of lesion, in and of itself, does not permit accurate inferences about cochlear processing ability. [Work supported by NIH.]
Coarticulation effects in Russian VCV utterances
Authors: Purcell Edward T.
Published: October 2005

Öman [J. Acoust. Soc. Am. 39, 151–168 (1966)], based on the speech of one informant reading a limited corpus, found that coarticulation effects between successive vowels did not occur in Russian VCV utterances. The present paper reports on a portion of the results of an expanded study of coarticulation and formant frequency interactions in Russian.
Preliminary report on a jitter extraction system
Authors: Doherty E. T.
Published: October 2005

Vocal jitter, the cycle-to-cycle variation in the frequency of vibration of the vocal folds, may be an effective indicator of the operational state of that mechanism. Thus far, calculation of the amount of jitter produced in the laryngeal wave has been a rather tedious process. The jitter extraction system proposed here is based on a special application of the fundamental frequency indicator (FFI) at the Institute for Advanced Study of the Communication Processes. Since the most recent models of FFI are capable of providing a reasonably precise determination of the duration of each cycle (of the glottal source wave), it is possible to modify the computational aspect of that system to measure also the difference in the duration of successive periods. Validation of this approach to vocal jitter analysis is based upon a comparison with a technique using high-speed photography of oscillographic traces reported by H. Hollien, J. Michel and E.T. Doherty [“A method for analyzing vocal jitter in sustained phonation,” J. Phonet. 1, 85–91 (1973)]. Such validation provides evidence that FFI can be utilized as the basis of a rapid and efficient jitter analysis system.
Formant frequencies corresponding to different vocal tract shapes
Authors: Ladefoged Peter , Rice Lloyd
Published: October 2005

A computer model was used to generate the formant frequencies corresponding to different vocal tract shapes. The degree of lip opening was varied exponentially in five steps. The tongue position was varied in equal steps in accordance with the two factors previously found to underlie English vowels. Sets of approximately 1500 different vocal tract shapes were generated, the exact number in each set depending on how the limits of possible vowels are determined. The formants of these sets of vowels are not evenly distributed throughout the ferment space. A high proportion of them are in the area of the front vowels from [i] to [æ]. In most cases ferment frequencies that differ by small amounts are associated with vocal tract shapes that also differ by small amounts. But there are also cases in which a set of formant frequencies can be produced with very different vocal tract shapes, usually because differences in lip positions compensate for differences in tongue shapes. [Work supported by NSF Grant 75-07158.]
Single number ratings for assessing open offices
Authors: Warnock A. C. C.
Published: October 2005

A large number of interzone attenuation measurements have been made on a variety of arrangements of open office components. All measurements were made in one-third octave bands using a computer controlled analyzer and followed in essence the procedure described in U. S. General Services Administration document PBS C.2. Six different methods of reducing the measurements to a single number rating were correlated with articulation index used as a reference. The NIC's rating used in PBS C. 2 did not correlate with articulation index as well as simple A-weighted level differences. Office and ceiling systems are typically assessed by making measurements at a height of 4 ft above the floor simulating seated humans. This need not be adhered to when only ceiling systems are to be rated. The effect reducing this height was examined both experimentally and theoretically, and good agreement was obtained. The range in measured values can be approximately doubled by reducing the measuring height from 4 to 2 ft. Again, using articulation index as a criterion, the NC 40 procedure for rating masking noise described in the PBS documents was compared with other more commonly used methods. The four-octave-band speech interference level was found to be an improvement.
Effect of sound-absorptive facings on partition airborne sound-transmission loss
Authors: Brown Steven M. , Niedzielski Joseph , Spalding G. Robert
Published: October 2005

Laboratory measurements of the effect of sound-absorptive facings on partition airborne sound-transmission loss are presented. For a double-leaf partition of 1/2-in. gypsum board on 2×4 in. studs, the application of sound-absorptive facings has led to improvements in transmission loss of as much as 10 dB or more in the 1/3-octave bands above 1 kHz. Corresponding, but smaller, improvements have been measured at lower frequencies. A preliminary theoretical analysis is presented.
Mechanical properties of Sitka spruce for guitars
Authors: Haines Daniel W. , Hutchins C. Jack , Lee Chih-Hung , Thompson Donald A.
Published: October 2005

A large number of Sitka spruce strip specimens were tested to determine their mechanical properties of acoustical importance. The specimens represent wood selected from the broad spectrum of musical grade spruce. Density was found to be a reliable indicator of the wood's acoustical performance: the lower the density, the better. The angle of cut also greatly affected the performance of the strips with a true quarter cut being best. An average along-the-grain to cross-grain bending stiffness ratio of 28:1 was measured, far higher than the 12:1 ratio (nominal) obtained for quarter cut plates. Mean values were (along-the-grain—cross-grain) logarithmic decrement: 0. 025/0. 075, Young's modulus: 121/4.37×109dyn/cm2, radiation constant 11.4/2.08×105 cm4/g sec, density: 0.455 g/cm3; all values were obtained at 70°F and 60% relative humidity. [Work supported by the C.F. Martin Organisation and the National Science Foundation.]
Reflection from cylinders and spheres at very high ka
Authors: Flax L.
Published: October 2005

Reflection characteristics for cylinders and spheres for values of ka = 2πa/λ as high as 1000 are presented. In that range, the sphere has a diameter (2a) more than 300 times the wavelength (λ) of the incident sound. The reflected pressure function variation with ka displays characteristics similar to low ka behavior and does not approach a limiting steady value derived from asymptotic solutions.
Statistical dependence of subpulse echoes in active sonar systems using frequency diversity
Authors: Mark William D.
Published: October 2005

Active sonar systems using waveforms consisting of M subpulses of different frequencies are a common method for counteracting the Rayleigh fading statistics of a single pulse echo. When frequency differences between adjacent subpulses are not large in comparison with the reciprocal of target-impulse response durations, the various subpulse echoes are not statistically independent. This lack of independence reduces the 2M statistical df that are associated with statistically independent echoes. Probability density functions of squared and summed subpulse echoes plus reverberation and noise are determined as functions of target-impulse response durations and subpulse frequency spacings. Limiting cases are shown to coincide with the classical chi-square distribution results. Effects of time constants of reverberation and noise-estimation circuits on receiver operating characteristics also will be discussed.
Vowel identification and subsequent context
Authors: Rudnicky A. I. , Cole R. A.
Published: October 2005

The disyllable [da ga] (with stress on the second syllable) was recorded on magnetic tape. When [ga] was excised from the tape, subjects heard [dag]. However, when a [ba], taken from a [da ba] utterance was substituted for the [ga], listeners heard [da i∧ ba]. Perception of the diphthong demonstrates that coarticulatory information contained in the syllable-final formant transitions of [da] is interpreted differently, depending upon the subsequent phonetic context. An experiment was performed to investigate the temporal course of this effect, by introducing successively longer silent intervals between the [da] and the [ba]. Given a sufficient separation, listeners again reported hearing [dag ba], instead of [da i∧ ba]. The results demonstrate that the interpretation of information in a syllable can be influenced by acoustic events in another, separate syllable occurring later in time. The results also suggest that perception takes into account allowable articulatory movements.
Prosodic information for vowel identity
Authors: Verbrugge R. R. , Shankweiler D. P.
Published: October 2005

Earlier research suggests that prosodic information is utilized by listeners in identifying vowels. The effects of variation in stress and tempo need to be distinguished. In this study, an adult male talker recorded nine American English monophthongs in /p—p/ syllables in each of four sentence contexts: two levels of syllable stress (stressed, destressed) were crossed with two rates of sentence articulation (slow, fast). Listeners made more errors when identifying syllables in isolation (average of 15% errors) than in sentence context (5%). Errors on the isolated syllables showed a bias toward “short” vowels, suggesting that the effective tempo perceived by listeners was slower than appropriate. Tokens of each syllable type were interchanged between sentence pairs so as to misinform listeners about the syllables' tempo and stress value. When tempo was mismatched, errors increased substantially on the fast syllables, showing a bias toward shorter vowels. No change was found when stressed and destressed syllables were interchanged, though formant frequency differences were greater than those between fast and slow syllables. The results contribute to a growing body of evidence that vowels are specified as much by sentential stress-timing structure as by cross-sectional formant measures.
Identification of vowels in “vowel-less” syllables
Authors: Strange Winifred , Jenkins James J. , Edman Thomas R.
Published: October 2005

This study investigated the importance of three kinds of acoustic information for the perception of American English monophthongs: steady-state frequencies, formant transitions, and syllabic duration. B + Vowel + B syllables containing nine vowels spoken by a male talker were digitized and modified to produce six sets of stimuli: (1) tokens in which the center “vowel” portion of each syllable was deleted, (2) center portions of each syllable, with initial and final portions deleted, (3) initial transitional portions presented alone, (4) final transitional portions (plus releases) presented alone, (5) syllables in which the center was deleted and the initial and final portions were temporally abutted, and (6) unmodified syllable controls. Results of identification tests with independent groups of naive listeners showed that identification of vowels in condition 1 (the “vowel-less” syllables) was just as accurate as identification of controls. Error rates in condition 2 were intermediate; errors in conditions 3, 4, and 5 were much greater than controls. These results indicate that vowel identity is specified acoustically by dynamic information (transitions and duration) available in the syllable pattern as a whole. [Supported by NIMH.]
Perceptual learning of vowel identity
Authors: Edman Thomas R. , Soskin Ron
Published: October 2005

In our recent experiments on vowel perception, subjects appeared able to improve their ability to identify vowels without the aid of training procedures or feedback. Two experiments explored this effect. In experiment I, error rates in the identification of vowels in b-vowel-b, vowel-b, and b-vowel syllables and isolated vowels were obtained at several points during an extensive test series. Improvement was shown for all syllable types throughout testing and ordinal relationships among them were maintained. In experiment II, a transfer paradigm was used to identify factors accounting for this improvement. Subjects received practice on d-vowel-d syllables or on isolated vowels produced by five talkers; practice consisted of a series of identification trails without feedback. An identification test on isolated vowels produced by a different set of talkers was then administered. Practice on both d-vowel-d syllables and on isolated vowels produced positive transfer relative to a control group. Also, a lower error rate on the test syllables was obtained after practice on the isolated vowels than was obtained after practice on the d-vowel-d syllables. Three factors are implicated in these results: (i) vocal tract normalization (ii) task learning, and (iii) perceptual learning. An interpretation emphasizing perceptual learning is offered. [Supported by NIMH.]
Speech perception in early infancy: perceptual constancy for the vowel categories /a/ and /⊃/
Authors: Kuhl Patricia K.
Published: October 2005

Six-month-old infants demonstrate perceptual constancy for the vowel categories /a/ and /l/ when both the critical (formant frequencies) and noncritical (fundamental frequency, pitch contour) acoustic dimensions are randomly varied (Kuhl, 92nd ASA Meeting). This report extends these findings to vowel categories that are spectrally and perceptually more similar. /a/ and /⊃/. Infants were tested in a task in which a head-turn response was reinforced with a visual stimulus in the presence of a phonetic token from one-vowel category but not in the presence of a phonetic token from the second-vowel category. Infants were trained on a single /a/ and a single /⊃/ token synthesized to simulate a male talker with a rise—fall pitch contour. The stimulus ensemble was then systematically increased until the tokens produced by a male, female, and child talker, each with two pitch contours (rise and rise—fall), were included in each vowel category. The data show that the /a/ and /⊃/ categories are readily differentiated by the six month old in this perceptual constancy paradigm. [Research supported by NICHD.]
Off-highway equipment, operator noise problem—real or imagined?
Authors: Day Lloyd
Published: October 2005

Problems of exposure to excessive noise levels in the construction equipment cab is the unwanted child of the off-high-way equipment industry. This presentation will attempt to relate to the actual measured environments for operators of equipment utilized in off-highway operations. Environmental noise conditions for typical vehicles such as crawler tractors, wheel loaders, and other off-highway equipment cabs will be presented. Problems encountered in definition and measurement of this environment, as related to current OSHA and MESA requirements, will be discussed. Specific treatments of off-highway equipment cab installations currently employed will be reviewed. The cost of various acoustical treatments to lower noise levels in typical models of off-highway equipment will be presented. Conclusion will include a brief summary of the application of these factors in determining future design concepts for the construction equipment operator's environmental compartment. Major emphasis will be placed upon the practicality of design techniques to insure compliance with current regulations by OSHA and MESA through contemporary noise reduction technques.
Crossover considerations in a three-way line-source array-loudspeaker system
Authors: Ashley J. Robert
Published: October 2005

The need for a three-way line-source array-loudspeaker system for reinforcement of a symphony orchestra in a summer outdoor concert is discussed. Electrical tapering of a line-source array-loudspeaker makes possible an octave range in a single array. An array 3.6 m long is crossed over to an array 2.4 m long at 200 Hz by an active third-order Butterworth filter. The midfrequency column is crossed over at 2 kHz to a horn tweeter array with a passive network. Performance data from 40 Hz to 10 kHz will be given.
Compatibility of a hearing aid and a telephone
Authors: Wojcik J. J. , Arndt H.
Published: October 2005

A telephone receiver is designed to generate an acoustic pressure in the ear cavity. This is the output specified by most Telephone Administrations. However, hearing aids don't have the ability to pick up exactly this specified telephone output (with exception of the in-the-ear type). This paper describes the pros and cons of several methods of a hearing aid coupling to a telephone receiver. The most common methods make use of (1) acoustic-leak radiation from the telephone receiver picked up by a hearing-aid microphone; (2) stray magnetic radiation from the telephone receiver picked up by a hearing-aid telecoil; (3) acoustomagnetic or magnetoacoustic active couplers; and (4) acoustic passive adaptors. Criteria for evaluation include acoustic signal quality, users convenience, uniformity, and versatility.