bluuebunny/crossref_metadata_2025 huggingface dataset:
The Difference Between the Inner- and Outer-Cell Populations in the Generation of CM and AP
Authors: Wang Chang-Yang , Dallos Peter
Published: October 2005

Literature review reveals that kanamycin creates highly selective damage primarily to the hair cells and the sequence of the damage to the hair cells is relatively regular in such a way that the degeneration of the outer hair cells starts at the basal turn and spreads upward, followed by the degeneration of the inner hair cells starting at the upper turns and spreading basalward, when the dosage per day and the number of days of kanamycin injection increase. The experiment was designed to create a pure cochlear lesion with selective damage only to the outer hair cells at least in the basal turn by careful control of the dosage of kanamycin and to obtain electrophysiological data including CM and AP from a pair of electrodes in the basal turn. The results show that the outer hair cell population is dominant over the inner hair cell population in generating CM, and the latter is about 25 to 30 dB less sensitive than the former in terms of the pseudothreshold of the onset AP. However, a “recruitment”-type phenomenon can be demonstrated for the AP input-output function in that in spite of the sensitivity change the maximum reaches near-normal magnitude. [Supported by grants from the NINDS.]
Some Effects of Short-Term Adaptation on Incremental Responses of Auditory Neurons
Authors: Smith R. L.
Published: October 2005

Single units in the cochlear nuclei of anesthetized Mongolian gerbils were studied using best frequency tones. The units showed an onset peak and a decay to a steady firing rate in response to 150-msec tone bursts. As in our previous study [SMITH, R. L., and ZWISLOCKI, J. J. (1971). J. Acoust. Soc. Amer. 50, 1520–1525], 300-msec tone bursts served as pedestals upon which intensity increments were placed. The time delay from pedestal onset to increment onset was fixed at 150 msec. Total onset firing rates have been determined in response to positive and negative increments. The “adapted” response curves so obtained are approximately parallel to the “unadapted” ones measured at the pedestal onset. They are shifted along the stimulus intensity scale relative to the unadapted curves, and the shift increases with the pedestal intensity. This pattern holds for intensity levels of the pedestal up to 15 dB re the threshold of the units. At higher levels, where the pedestal responses show saturation effects, the slope and the maximum firing rate of the incremental response curves decrease.
Input-Output Functions of Binaural Low-Frequency Medullary Neurons Insensitive to Interaural Time
Authors: Moushegian George , Rupert Allen L.
Published: October 2005

A significant number (about 30%) of the binaural low-frequency medullary neurons of kangaroo rat are insensitive to interaural time differences. These neurons do not respond in a cyclic manner to the interaural time differences of any frequency within their response areas, but they are activated in a differential manner by small interaural level differences. The discharge rate to a binaural signal for one group of these neurons is greater than the discharge rate to a monaural input. For the other group, the discharge rate to monaural is greater than to binaural stimulation. In the first group, we have binaural facilitation or summation; and in the second, binaural suppression. The most important distinction between these two types, however, is that the facilitative type does not phase lock to monaural or binaural tones, whereas the suppressive type responds in synchrony to either a monaural or binaural sound. [Supported in part by NINDS Grant.]
Noise Propagation in Corridors
Authors: Tocci Gregory C. , Davies Huw G.
Published: October 2005

As an effort to reduce noise propagation in corridors, a study has been undertaken to evaluate the use of absorbing and shielding baffles in corridors. Both noise attenuation in the corridor itself and also the reduction of noise propagating through open doors into rooms adjacent to the corridor are considered. A discussion is presented of the effectiveness of both the shielding and the absorbing components of the noise reduction for baffles oriented parallel to and perpendicular to the corridor direction. Predictions based on approximate modal summations for the power flow in the corridor are compared with experimental results. [Work supported by NSF.]
Electrets in Miniature Microphones
Authors: Fraim Freeman , Murphy Preston
Published: October 2005

The electret capacitive microphone element is ideally suited for miniature applications. The simplicity of its structure leads to a straightforward design even in very small devices. Since the electret foil is the only moving element, and the foil-back electrode spacing the only critical dimension, the electret cartridge is simple in design and extremely rugged. Careful design of the cartridge and associated preamplifier is required to minimize the microphone's self noise. The principal aspects of a miniature electret microphone design are discussed, including the cartridge and the preamplifier, and two examples of small omnidirectional microphones are given.
An Approximate Model for Parametric Acoustic Source Design
Authors: Mellen Robert H. , Moffett Mark B.
Published: October 2005

A parametric acoustic source is comprised of a high-amplitude radiated sound field of two frequencies. Because of fluid nonlinearities, this primary field generates a secondary sound field at the difference frequency. Using a simplified mode[ for the primary sound field of a piston transducer, the secondary source levels and directivities generated by such a parametric source have been predicted. The extent of the primary field is assumed to be limited by linear and nonlinear absorption, and this limit is considered to occur in either the collimated-beam or the spherically spreading portions of the primary field. Numerical values have been computed for a variety of conditions and compare favorably with the experimental data obtained to date.
Farfield Interactions in the Parametric Radiator
Authors: Konrad W. L. , Mellen R. H. , Nelson J. L.
Published: October 2005

In the parametric radiator, the region where most of the generation of the difference frequency occurs can be in the near- or farfield or shared between them depending on the primary frequency, source level, and the projector size. Most of the experiments conducted previously have operated under conditions of predominantly nearfield generation. An experiment is described that is tailored to examine the parametric radiator where the bulk of the generation occurs in the farfield. The experimental source levels and beam patterns are found to be in close agreement with the Mellen-Moffett model of the radiator. For some conditions, the beamwidth of the difference frequency is in fact narrower than that of the primary pattern and approaches the square of the primary pattern, a result predicted by the model. The application of the model is illustrated by examples of both near-and farfield generation parametric sources.
Laminagraphic Investigation of Pulse Register (Vocal Fry) Phonation
Authors: Hollien H. , Allen E. L.
Published: October 2005

The physiologic and aerodynamic parameters of modal register phonation have been extensively investigated; not so well researched are these same parameters for the loft (falsetto) and, especially, the pulse (vocal fry) registers. The present study was designed to add to the knowledge being accumulated for the pulse register—in this case, with regard to the relationships of both vocal fold and ventricular fold area and thickness correlates of variation in f0. Subjects were seven males and six females, with normal healthy larynges, who could sustain pulse at high and low repetition rates. Coronal cross-sectional laminagrams were obtained by means of the stroboscopic laminagraphic (STROL) technique. It was found that there were no trends of any type for area or thickness change as a function of frequency variation. However, it was found also that the ventricular folds impinge upon, or load, the true vocal folds for this type of phonation. Hence, it is suggested that the ventricular folds may act to damp vocal fold vibration by coupling their passive mass with that of the true folds. Implications relative to theories of phonation will be discussed.
Parametric Study of Single Motor Unit Waveforms in Upper Articulatory Musculature
Authors: MacNeilage P. F. , Sussman H. M. , Hanson R. J.
Published: October 2005

Waveforms of single motor units were investigated, primarily in four muscles; the genioglossus, geniohyoid, mylohyoid, and anterior belly of the digastric. Units were sampled at various depths up to 25 mm from concentric bipolar electrodes inserted vertically into the tongue from points inferior to the mandible and near the midline. Units were predominantly of the usual triphasic form although many other types of waveform were observed. Most triphasic potential durations ranged from 5–7 msec, as compared, for example, with 2.5–4 msec from the same muscles with bipolar hooked wire electrodes. Variables determining these waveforms, and differences in waveforms and unit amplitudes from muscle to muscle will be discussed. [This work was supported by grants from the National Science Foundation.]
Lip and Tongue Pressure Patterns during Syllable Productions
Authors: McGlone Robert E. , Proffit William R.
Published: October 2005

Strain-gauge transducers were placed on the lingual side of the dental ridge of the maxilla and mandible and on the labial side of the mandible. These were positioned to record contact pressures along ridges in five locations from the sides and in the midline. Lip and tongue contacts were recorded as subjects repeated VCV syllables containing /i/, /a/, /u/, and /s/. Different pressure patterns were found both between and within syllable utterances. Pressure peaks from the sides of the tongue corresponded to each phoneme while pressure peaks nearer the midline corresponded temporally with the consonant. Lip pressure peaks were related only with the consonant. Tongue tip and midline lip activity showed a definite movement away from the transducer for the entire syllable. The shape of the contact peaks were related to the vowel used in the syllable.
An Electromyographic Investigation of Articulatory Movements for Bilabials in Normal and Cleft Palate Speech
Authors: Hirano Minoru , Sanui Noritake
Published: October 2005

Activity of the orbicularis oris, levator veil palatini, and lateral cricoarytenoid muscles for bilabials (/p/, /b/, /m/) was investigated electromyographically in normal adults and cleft palate speakers. The orbicularis oris muscle presented a marked peak activity prior to the bilabials in the normal subjects. The levator veli palatini muscle were active for the oral sounds and inactive for the nasal as has been expected. However, its activity was not of a consistent level during successive oral sounds. Especially, the levator often showed a marked peak activity prior to plosives corresponding to the orbicularis oris. In cleft palate speakers, the peak activity before the plosives was less marked. Instead, the lateral cricoarytenoid muscle presented a marked peak activity, which suggested a gesture for glottal stop. The levator veil palatini muscle often presented a similar activity mode as in the normal.
Approximate Equations of Motion for Elastic Rings and Helical Coils of Small Pitch
Authors: Haines D. W.
Published: October 2005

One-dimensional equations of motion are obtained for in-plane deformation of rings. The results also apply to helical coils of small pitch. The equations are obtained from the variational equations of elasticity by expanding the displacements in a Taylor series of the radial coordinate. Truncation of the series leads to a set of two simple equations of motion, capable of describing the first two modes of harmonic wave propagation. These modes correspond to essentially extensional and flexural motion which are highly coupled at long wavelengths. As in straight bars, such a formulation is limited in accuracy to rather low frequencies. The frequency range is greatly extended by including one more term in the truncated series; this leads to three equations of motion and provides for a thickness-shear mode. Comparison is made with the dispersion curves of the recently solved and considerably more complex generalized plane-stress case. From this comparison, the curves from these equations are seen to include the complex segment and to be highly accurate. Boundary conditions are obtained for finite coils and ring elements. [This work was supported by the National Science Foundation.]
The Precision of Reverberant Sound-Power Measurements
Authors: Lubman David
Published: October 2005

Determination of sound power in a reverberation room is subject to a random error whose size can be estimated and controlled by the knowledgeable laboratory manager. Under ideal measurement conditions the random error can be expressed as a product of three factors: a frequency-averaging factor governed by spectrum shape and room reverberation time, a spatial-averaging factor determined by the number and separation of fixed microphones or the path shape and size for a traversing microphone, and a rotating-diffuser factor depending on the size and shape of the rotating diffuser in relation to room size and reverberation time. Continuing progress in this field is teaching us to incorporate nonideal measurement conditions into our error estimates. In particular, we report progress in understanding the effects on random error due to (1) finite averaging time, (2) presence of a direct field component, and (3) insufficient modal overlap at low frequency.
Summary of Papers and Open Discussion
Authors: Ingard Uno
Published: October 2005

Dr. Ingard will lead the summary and open discussion of the papers presented in this session. Questions and points deserving further discussion will be directed to individual authors, after which questions will be accepted from the floor.
The Acoustic Behavior of the Outer-Middle-Ear Complex of Man and Guinea Pig
Authors: Sinyor Albert , Laszlo Charles A.
Published: October 2005

In this study, the acoustic-transmission characteristics of the human and guinea-pig ear canals were compared. According to Wiener [J. Acoust. Soc. Amer. 18, 401–408 (1946)], the pressure response of the human ear canal is similar to that of a tube open at one end and rigidly terminated at the other. This indicates that in man, the middle ear acts as a high-impedance termination and hence it does not load the ear canal. In the guinea pig, however, we have found that the pressure response of the ear canal is affected by the loading of the middle ear [J. Acoust. Soc. Amer. 50, 92 (A) (1971)]. In particular, two maxima were observed in the experimental curves and these were found to correspond to two peaks in the impedance curve of the guinea-pig middle ear. To facilitate the interpretation of the experimental results, a computer simulation study of the outer-middle-ear complex was performed for the human and guinea-pig ears. The responses predicted by the simulated electroacoustic models were very similar to the experimental data. To compare the extent of impedance mismatch between the outer and middle ear in man and guinea pig, the reflection and transmission coefficients at the eardrum were calculated.
The Behavioral Effects of Chronic Exposure to Impulsive Noise in Chimpanzees
Authors: Koestler A. G. , Farrer D. N. , Pegram G. V. , Krausman P. R.
Published: October 2005

Two young male chimpanzees were exposed to 24 impulsive noises each night for 30 consecutive nights. The subjects' daytime performance on a temporal discriminative task was significantly poorer than pre-exposure performance standards. Although a general trend towards recovery became evident the subjects never fully regained consistent pre-exposure levels of performance. The data suggest that chronic nocturnal exposure to impulsive noise has a significantly detremental effect on the behavioral effectiveness of performing subjects.
Temporary Threshold Shift from Low- and High-Frequency Intermittent Noise as a Function of “Off” Time
Authors: Ahaus W. H. , Ward W. D.
Published: October 2005

Eight listeners were exposed via earphones to two different octave bands of noise: 500–1000 Hz at an intensity of 115 dB SPL, and 1500–3000 Hz at an SPL of 110 dB. Six separate exposures to each noise were conducted: once to the noise presented continuously, and once to each of five intermittent noise conditions. For the intermittent conditions, “on” time was held constant at 50 msec and “off” times varied between 50 and 450 msec. Exposure durations were based on off times (the longer the off time the longer the exposure), such that all exposures contained the same energy. Exposure durations ranged from 3 min for the continuous exposure to 30 min for the 450-msec-off condition. TTS2 was measured after each exposure for three test frequencies within 1 oct above the upper cutoff frequency of the noise. There was a systematic tendency for the mean TTS to increase with off time for the low-frequency exposure, in contrast to a much flatter function following exposure to the high-frequency noise. The results are interpreted in terms of their relation temporally to the latency and relaxation of the acoustic reflex. [Research supported by the Deafness Research Foundation.]
Comparison Between Hair Cell Losses and Permanent Threshold Shifts Produced by Three Levels of Impulse Noise
Authors: Henderson Donald , Hamernik Roger P. , Sitler W.
Published: October 2005

The cochleas of chinchillas exposed to three levels of impulse noise described in the previous abstract were examined using the surface preparation techniques and Nomarski microscopy. The cochleagrams and AER audiograms 30 days postexposure were compared. The animals exposed to 155 dB impulses showed no PTS, but all animals showed large and consistent outer hair cell (OHC) lesions at 6 to 12 mm, from the apex. All cochleas had relatively mild and varied inner hair cell (IHC) losses. The 161- and 166-dB exposures produced PTS values ranging from 0 to 45 dB. The cochlea-grams exhibited two basic types of lesions: (1) low level losses of IHC and OHC throughout the entire cochlea; (2) broad lesions of total OHC loss accompanied by less severe IHC losses. The most dramatic results are (1) complete recovery of hearing sensitivity with large cochlear lesions; (2) when there is a PTS, cochlear lesions were found in all animals; however, the exact magnitude and location are difficult to specify on the basis of the postexposure audiogram.
Cochlear Degeneration Following Impulse Noise Exposure
Authors: Hamernik Roger P. , Henderson Donald , Sitler Ronald W.
Published: October 2005

Twenty guinea pigs were exposed to PTS producing impuses of either 166 or 161 dB peak SPL. The animals were sacrificed at postexposure times of 12 h to 50 days, and the cochleas were histologically examined. At 12 h postexposure, hair-cell lesions are observed without phalangeal scars. The lesions are bordered on both sides by greatly swollen and distorted hair cells. This damage is observed to increase in extent for up to 30 days. Atrophic changes in the stria vascularis are seen in regions adjacent to hair-cell lesions. Atrophy of the capillaries of the spiral ligament and swelling of the endothelial cells of the vas spiralis appear but are not specific to the hair-cell lesions. Other changes include loss of supporting cells, collapse of the tunnel of Corti, degeneration of the limbus, and loss of nerve fibers. These experiments present a paradox: Over a period of 30 days the cellular damage grows progressively worse while, presumably, hearing sensitivity is recovering.
Ultrasonic Synergism in Biochemistry, Ultrasonic Irradiation of Nucleic Acids and Microorganisms, Applications to Sterilization
Authors: Boucher R. M. G. , Last A. J.
Published: October 2005

In this lecture, a review is made of recent work and concepts dealing with the insonation of nucleic acids (DNA, RNA transfer, etc.). Possible implications in the field of genetics are reviewed briefly. The role of free radicals during the insonation of microorganisms is analyzed with particular emphasis on the behavior of highly resistant spore strains. A new sterilization theory is exposed which is based upon synergistic effects observed during the insonation of aqueous glutaraldehyde solutions at reasonably low temperature (54°C). Results obtained with resistant B. subtilis spores (including AOAC) are given. Conclusions are drawn regarding the use of this technique in hospitals and industry (continuous sterilization of disposables). Economic aspects of the new synergistic sterilization method are analyzed.
Pressure Fluctuations Resulting from the Interaction between a Shock Wave and a Turbulent Boundary Layer
Authors: Grande E.
Published: October 2005

An experimental investigation has been conducted to determine the pressure fluctuations in the external flow resulting from the interaction between an oblique shock wave and a turbulent boundary layer. The flow perturbations were measured and interpreted by means of supersonic hot wire techniques. It was found that attached and weakly separated interactions generate weak fluctuating disturbances. However, as the incident shock strength was increased to generate a strongly separated interaction, the fluctuation levels were correspondingly increased. Comparison with Ribner's shockturbulence interaction theory showed that his interaction model is not directly applicable to this particular interaction phenomenon. The experimental results show that the pressure fluctuations in the external flow are mainly generated by the oscillating separation shock. A qualitative analysis, based partly on Ribner's theory, suggests that these shock oscillations are caused by nearfield pressure fluctuations generated by the interaction between the incident shock and the boundary layer, amplified in the separation interaction region, and fed upstream within the boundary layer to the separation shock.
Effect of an Ice Layer on Arctic SOFAR Propagation
Authors: Kutschale Henry W.
Published: October 2005

The effect of an ice layer on Arctic SOFAR propagation is investigated from the normal-mode solution of the sound field in multilayered media. For an ice layer 3 m thick, typical of the central Arctic Ocean, the effect on pressure amplitudes at depth and dispersion is small, but even this thin ice sheet causes a large change in particle motions near the surface. Waves are elliptically polarized in the ice in the plane of propagation. Particle motion is retrograde elliptical at the surface and prograde elliptical at the bottom of the ice. This orbital motion is similar to that of flexural waves in the ice. Flexural waves generated by large-scale ice movements at the boundaries of floes are the principal background noise in the ice. It is significant that a node of horizontal particle motion often does not occur at the same depth in the ice for both hydroacoustic waves and flexural waves. This effect may be useful to improve the signal-to-noise ratio when horizontal component geophones are used as listening devices.
Acoustic Propagation in a Wedge
Authors: Hudimac A. A. , Bradley D.
Published: October 2005

The wavefield due to a point source in a fluid in a wedge cannot be specified solely by the method of images (except for a wedge angle equal to a submultiple of π). Various methods have been developed by which a finite number of real images are augmented by an integral term. In the case of Bromwich theory, the theorem of Plemlj and Sokhotskikh is used to prove the correctness of the added integral. The connection is made between this formulation and our earlier work, in which the wavefield is developed in terms of a Riemann surface fundamental solution. Specifically, the nature of the field in the ensonified and diffracted region is given, and the integralterm contribution is discussed in terms of virtual sources.
Impedance-Transforming Wave Systems with Spatially Varying Density or Elasticity
Authors: Shaw E. A. G.
Published: October 2005

Acoustic impedance can be transformed either with an acoustic horn that controls the variation of wavefront area as the wave progresses, or by transmitting the waves through a medium in which there is a gradient of density or elasticity. Analysis shows that for plane waves a medium in which density varies as (B+mx)−2 or elastic modulus as (B−mx)2, where x is distance and B and m are constants, is analogous to the ideal exponential horn. Furthermore, radial variations of density and elasticity can readily be found which transform the behavior of sectoral and conical horns into the acoustic equivalents of exponential horns. Since the wave equation is separable in both cylindrical and spherical coordinates, these solutions are exact. In practice, the effective density of a fluid medium can be increased by introducing suitable arrays of obstacles, and the bulk modulus of a liquid decreased by compliant inclusions. The relationships between array size, bandwidth, and damping are discussed, and three artificial fluid structures are suggested.
Brass Instrument Design and the Theory of Horns
Authors: Benade A. H.
Published: October 2005

Engineering the design of horns has been chiefly directed toward transducer applications, where freedom from resonances and a low cutoff frequency are desirable. In the musical horns, easy oscillation and good tuning both call for a high cutoff frequency and accurately placed resonances. The radiation load must not be more than a perturbation at playing frequencies. Horns of rapid flare are required, for which plane-wave theory is inadequate. The “reduced” pressure wave function ψ(z) (=pS12) is mathematically and conceptually convenient, where S(z) is the area of the spherical wavefront at the point z along the horn axis. The “reduced” spherical wave equation ψ″+[k2−U(z)]ψ = 0 (studied by Jansson) is tractable, the horn function U being easily visualized in terms of the transverse and longitudinal curvatures of the horn. Exact solution of the equation is not always required, since useful estimates of U can be made by inspection, whence calculations related to phase integrals, plus perturbation theory permit excellent approximations to the resonance frequencies. Different perturbation methods are useful along the horn depending on local flare. Preexisting horns may be diagnosed and corrected on the basis of laboratory data or “musicians' experiments.” Practical examples will be discussed.
Persisting Questions in Steady-State Measurement of Noise Power and Sound Absorption
Authors: Schultz T. J.
Published: October 2005

Most steady-state methods for measuring the noise power of equipment and the sound absorption in a room depend on knowing the sound power output of the standard source. But the output of any sound source depends in principle on the radiation impedance presented to it, and this impedance is likely to change with the location of the source, as well as with changes in the amount and distribution of absorptive material in the room. Moreover, no generally accepted method is available for measuring the sound-power output directly. For these reasons, the validity of steady-state methods has been under suspicion for some time. This paper summarizes recent progress in making steady-state methods respectable but calls attention to some remaining problems.
On Loudness as a Function of Tone Duration
Authors: Zwislocki J. J. , Sokolich W. G.
Published: October 2005

According to the prevailing evidence, the loudness level of short tone bursts increases with their duration at a rate of about 10 dB/decade. It is not clear, however, whether the data refer to total loudness or to instantaneous loudness reached at a particular point in time. In order to answer the question, listeners were instructed to respond to instantaneous loudness at the end of tone bursts in one series of experiments and to total loudness in another. They had to adjust the loudness level of a 10-msec comparison burst accordingly. Not all listeners could change their criterion, but those who could showed that instantaneous loudness depends little on tone duration, whereas total loudness increases at a rate of almost 10 dB/decade up to a duration of at least 500 msec. These results are consistent with our findings on temporal loudness effects in pairs of short sound bursts. Previous results according to which loudness increases up to a duration of about 80 msec may be explained by the listeners' tendency to respond to total loudness at very short durations and to instantaneous loudness at longer ones.
Acoustical Features and Perceptual Cues of the Four Tones of Standard Colloquial Chinese
Authors: Chuang C.-K. , Hiki Shizuo
Published: October 2005

Monosyllabic, bisyllabic, and trisyllabic words of various phonemic constitutions were spoken with the four tones of standard colloqual Chinese by three speakers, two male and a female, born in Formosa, and the typical pitch patterns of the four tones for each speaker were extracted from these speech samples. Effects of the position of the syllable and the context of the kind of tone in a word on the average pitch frequency, range of change in pitch frequency, and duration of the typical pitch patterns were also analyzed. Then, the listening test was conducted to identify the kind of tone of the speech samples, and perceptual cues of the four tones were investigated through the confusion among tones, which was characteristic of each of native and nonnative listeners groups and each of nonsense and meaningful words groups. Based on the results of the acoustical analysis and the listening test, a set of essential features of the four tones were derived, and a generative model of pitch pattern of the tone accent was proposed. The results were examined utilizing listening test with the synthetic speech generated by the model. Effect of intensity pattern on the tone accent was also discussed.
The Perceived Pitch of 23 Prevocalic Constants
Authors: Peterson M. M. , Asp C. W.
Published: October 2005

Twenty-three prevocalic consonants were arranged on tape in 253 different pairs (e.g., /pa-sa/). Twenty-three normal-hearing listeners utilized the method of paired comparison to judge each pair according to the consonant that was “higher” in pitch. Coefficients for consistency for all listeners and the coefficient for agreement among listeners were significant. The perceived pitch among the 23 consonants was significantly different. Voiceless consonants were higher than voiced consonants. Fricatives and affricatives were higher than nasals. Place of articulation was different, but no particular order was apparent. The consonants were rank ordered from low to high pitch from the responses of all 23 listeners and also from the 10 best listeners. Both rank orders were compared to Templin's norms and Poole's norms for the acquisition of speech sounds. All correlation coefficients were positive, but only the coefficient between Poole's norms and the 10 best listeners reached significance. In addition, the two rank orders were compared to Guberina's ordering of consonants according to “optimal octaves.” Both coefficients were significant.
Analysis and Evaluation of Time-Domain Techniques for Pitch Extraction
Authors: Fujisaki Hiroya , Tanabe Yoshihisa
Published: October 2005

Recent techniques for pitch extraction are mostly based on detection of short-time periodicity of certain time functions, such as autocorrelation function or cepstrum, derived by some transformations of the original speech signal. No systematic studies, however, have been made for the analysis and quantitative evaluation of the performance of these techniques. This paper presents results of both theoretical and experimental investigations on this problem. Deterioration in the observed periodicity is caused partly by the nonstationarity of the signal itself, and partly by the finite length of the time window of observation as well as its relative phase to the excitation signal. These effects are theoretically estimated for a given set of parameters of the speech signal and the analysis procedure, and lead to quantitative evaluation and comparison of various techniques thus far proposed. Results of the theoretical analysis are then confirmed and supplemented by experimental analysis of performances of these techniques for natural speech.
Observations on the Vital Capacity of Singers
Authors: Large John W.
Published: October 2005

The vital capacities of 20 male and 20 female singers attending a summer workshop program of the National Association of Teachers of Singing were measured by a Collins respirometer. The data were compared with predicted vital capacity based on Baldwin's formulas for normal subjects. A wide range of results was obtained suggesting that singing teachers should not take for granted an increase in vital capacity due to the activity of singing. On the average, however, the singers showed roughly 16% greater measured vital capacity than predicted for the corresponding age and height. The highest percentage of increase in measured vital capacity was achieved by a male subject, roughly 50%. The highest value among the female subjects was 43%. It was also interesting that the elder age group (above 50 years) still showed some increase in vital capacity. There appeared to be little correlation between the increase in vital capacity and either body surface or number of years of singing experience. The study furnishes an example of potentially useful research that might be conducted at NATS conventions and workshops.
Spectrum Development with Playing Level in Wind Instruments
Authors: Worman W. E.
Published: October 2005

Starting from the theory of musical wind instruments proposed by Benade and Gans and further developed by the author, it is possible to draw very general conclusions about the development of the spectrum in the mouthpiece as a function of loudness. A threshold blowing pressure exists below which no oscillations are possible. Near threshold, the pressure amplitude of the fundamental is proportional to the square root of the excess of the blowing pressure over its threshold value. The pressure amplitudes of the higher harmonics can be written as Pn = (P1/En)n|Zn|, where Pn is the pressure amplitude of the nth harmonic, |Zn| is the magnitude of the input impedance of the bore at the frequency of the nth harmonic, and En is a constant that can be evaluated experimentally and calculated for simple systems. Experiments by Benade on many types of wind instruments (including clarinet, bassoon, trumpet, and saxophone) show that this form of spectrum development takes place over a surprisingly large range. In many instruments, the range is about 40 dB in the pressure amplitude of the fundamental (pianissimo to mezzoforte). Observed departures from this behavior may be understood in terms of the same basic theory.
Experimental Investigation of the Statistics of Sound-Power Radiation in a Reverberant Room
Authors: Smith Wayne F. , Bailey J. Ronald
Published: October 2005

The measurement of sound-power injection into a reverberant room is subject to statistical uncertainties owing to the large fluctuations of SPL with variation of source and/or receiver position. Low-frequency pure-tone sources generally require many microphone and source positions if radiated sound power is to be accurately measured. An experimental investigation of low-frequency pure-tone sound radiation into a reverberant room has been conducted using both an 8-in. loudspeaker and a 30-in. loudspeaker at five source positions. The resulting standard deviation of sound-power output of the smaller speaker with source position is in excellent agreement with existing theory if the data is adjusted to account for the finite number of independent microphone readings. Standard deviation of the sound-power output of the larger speaker with source position is significantly lower than the theory at frequencies below 500 Hz. [NASA is acknowledged for partial sponsorship of this work.]
Plane-Wave Admittance of an Elastic Half Space
Authors: Nigam Anant K.
Published: October 2005

The ratio of complex amplitudes of the normal velocity and the normal stress (i.e., the admittance) of a plane displacement wave traveling on the surface of an elastic half space is studied. The admittance is computed as a function of the traveling wave parameters of the surface wave. Four ranges of phase velocity of the surface traveling wave have been identified, which are the ranges of velocity separated by the three characteristic speeds in the half space (the Rayleigh, shear, and dilatational speeds). In each of the four velocity ranges, the plane-wave admittance of the elastic half-space exhibits a different functional form. Simple interpretations for each functional form of the admittance are provided in analogy with a single-degree-of-freedom, mass-spring-dashpot system. The correlation of half-space behavior (to traveling waves on the surface) with the nature of the vibration pattern within the half-space is discussed.
Capacitance Microphone Dynamic Membrane Deflections
Authors: Warren J. E. , Brzezinski A. M. , Hamilton J. F.
Published: October 2005

In order to describe the operation of capacitance microphones accurately, it is necessary to have solutions for both the static and dynamic deflections of the moving electrode. The authors have previously presented numerical solution approaches to the static deflections caused by the electrical biasing of the microphone. The present paper describes an application of finite difference methods to the differential equations describing the dynamic membrane motion due to the acoustic excitation. The solutions include the effects of the static deflections and the motion of the thin air film between the microphone's electrodes. The numerical results are compared with published results for simplified stationary electrode geometries and with experimental data on more complicated geometries at different tension levels. The predicted mode shapes and resonant frequencies change greatly depending upon the magnitudes of the membrane tensions and the back chamber volume.
A Kirchhoff Solution to the Diffraction by an Elastic Wedge
Authors: Eisler T. J. , New R.
Published: October 2005

The scattering of an incident plane wave from an elastic wedge has been calculated using the Kirchhoff approximation. In this method reflected and transmitted waves are first calculated using Snell's law. The boundary values obtained in this way for the pressure and its normal derivative on the surface of the wedge are then substituted into the Helmholtz integral. The radiation pattern of the diffracted wave has been calculated for infinite steel wedges in water and compared with rigid wedge solutions. Close agreement is found except in certain directions corresponding to transmitted plane waves not present in the rigid case. The effect of penetration on the diffracted wave becomes more important as the number of internal reflections within the wedge increases. The method also introduces some spurious infinites in a finite number of directions.
Punch Press Noise, A Program for Analysis and Reduction
Authors: Shinaishin O. A.
Published: October 2005

Occupational Safety and Health regulations are demanding the search for solutions to industrial noises in factories. Presses are among the more common and most noisy of the offending manufacturing machines. This paper discusses an approach to reducing the noise at the source which is the most desirable solution. Experimental and analytical work was done to isolate the separate sources of noise and their contribution to the over-all noise. Presses were instrumented to monitor the different events generating excitation forces, and to measure the vibration levels of significant parts. Analysis of the data from vibration and sound made possible the correlation between the over-all sound, the different events, and the vibrations of key parts in the press. Steps are outlined to change the character of forces and vibrating parts to reduce the noise. Preliminary laboratory tests indicate that substantial noise reduction can be achieved once the diagnostics have been completed successfully.
Control of Noise Sources on Sea-Going Tow Boats
Authors: Harford K. D. , Price A. J. , Siddon T. E.
Published: October 2005

The paper describes noise-control studies on a number of commercial tow-boats operating on the North-Pacific coast. Noise levels in these small vessels often exceed 80 dBA in the sleeping accommodation areas. Crew may be continuously exposed to these high levels of noise for periods of several days. A variety of diagnostic techniques have facilitated the separation and localization of sources of structure-borne and air-borne sound. These include the use of artificial sources, spectral and cross-correlation analysis, vibration analysis, and statistical energy methods, together with the less sophisticated trial and elimination approach. On most boats, structure-borne vibration made the greatest contribution to noise levels in occupied spaces. The high noise levels were directly attributed to one or more mechanical deficiencies on each boat. Such deficiencies included faulty bulkhead design, inadequate acoustic isolation of crew quarters, and, principally, the widespread practice of mounting the engine, gear box, and ancillary components rigidly to the main structural elements of the vessel. Implementation of noise-control recommendations resulted in significant noise reduction on several vessels. Quantitative results for isolation of both engines and occupied spaces are presented.
An Acoustic and Electromyographic Investigation of Consonant-Vowel Transitions in the Speech of Deaf Adults
Authors: Rothman H. B.
Published: October 2005

An acoustic and electromyographic investigation of the speech of normal-hearing and deaf speakers attempted to answer questions concerning formant transitions, coarticulation, and neutralization of vowels in the speech of deaf adults. In order to accomplish this, EMG and acoustic recordings were made simultaneously as each subject read a constant phrase into which a variable key word was embedded. The deaf speakers chosen for this study were judged to be above average in intelligibility for deaf talkers with a profound bilateral hearing loss of early onset. Acoustical analysis was performed by making wide-band spectrograms of selected recorded stimulus items. The amplitude display of the sonograph was used for relating electromyographic events to acoustic events in time. The results of this study showed that the transitions of deaf speakers had a restricted range of movement and a slower rate of movement than those of normal speakers. The speech of the deaf shows relatively small coarticulation effects, their vowels tend to be neutralized regardless of the context, and they tend to begin an articulatory sequence in a similar manner regardless of the context. The deaf speakers also exhibited difficulty coordinating articulation with phonation and their articulatory behavior showed greater variability than did the articulatory behavior of the normal speakers. The discussion of the results will indicate their implications for speech training of the deaf.
Acoustic Measures of Nasalization and Nasality
Authors: Scwartz Martin F.
Published: October 2005

In this paper a description is given of four of the primary acoustic features that have been found to be associated with the nasalization of vowels. Comparative normal-nasal spectra are portrayed for several vowels, and explanations to account for each of the prominent within-vowel differences are offered. In addition, other evidence is presented which is used to suggest that each of the primary acoustic features of nasalization may also be the result of factors quite unrelated to nasal coupling. These factors, manifestations of typical normal variations, are used to develop the thesis that it is not readily possible to isolate the acoustic features of nasalization within a given vowel spectrum. The implications of this thesis are then manifest in a questioning of the validity of the term, nasality.
Evaluating Car Safety by Computer-Simulated Crashes
Authors: Melosh R. J.
Published: October 2005

Computer simulation of car crashes prescribed for safety assurance offers the prospect of relatively precisely controlled, densely instrumented, low cost testing. The computer environment engenders short lead times, extensive problem descriptive data, and automatic data reduction. This presentation describes the principal concepts of mathematical simulation of the nonlinear dynamic characteristics of an automobile structure. It shows that the number of calculations are three orders of magnitude greater than for a comparable linear system, illustrates the importance of developing a special purpose computer code, shows the effectiveness of automatic error control, and expounds on the complexity of validating the numerical analog. Figures showing simulation results demonstrate the fidelity with which time dependent, large deflection, and finite strain behavior are emulated for simple problems. Physical and computer accelerations for a head-on crash configuration are compared.
Detection of Sampled Signals
Authors: Rowlands R. O.
Published: October 2005

In correlating samples of a bandpass signal against a reference, two quadrature sets of the input samples are often used to ensure that a high output is obtained at zero delay. It is shown that this duplication is unnecessary as even if the single sample set represents the quadrature version of the reference, at least two samples of the output signal will occur that can be processed further to give an output within 1 dB of the theoretical peak.
Theoretical Design of Nearfield Calibration Arrays of Arbitrary Configuration
Authors: Van Buren A. L.
Published: October 2005

The Trott nearfield calibration array (NFCA) is an experimentally proven concept for determining the farfield acoustic radiation of large underwater transducers from measurements in the nearfield. Existing successful NFCAs are large planar configurations of small reciprocal transducers whose responses are amplitude shaded so that the NFCA as a source produces a nearly uniform plane wave directed normal to the NFCA throughout the volume to be occupied by the unknown transducer. Trott obtained shading coefficients that are effective over a wide frequency range by the use of semiempirical methods that are applicable to linear or planar arrays. In this paper, a rigorous derivation of the NFCA reciprocity principle is presented for the first time. The results allow for both amplitude and phase shading and are applicable to NFCA configurations other than linear or planar. A numerical technique based on this principle is described that produces an optimum set of shading coefficients for an arbitrary NFCA configuration with a prescribed plane-wave direction, volume, and frequency domain. As an example, the design of a cylindrical NFCA suitable for calibrating an enclosed cylindrical transducer without mechanical rotation is presented and discussed.