bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impedance-tube calibration of a reverberant room for the measurement of sound power in tones
Authors: Bies David Alan , Hansen Colin H. 
Published: October 2005

The use of an impedance tube and horn for the absolute calibration of a 180-m3 reverberant room for the measurement of sound power in tones is discussed and demonstrated. The results of the calibration procedure are found to compare quite favorably with results obtained using a one-third-octave-band decay method. For a modal overlap index greater than 5, corresponding to frequencies greater than 400 Hz, the difference in the predictions of the two methods is less than 0.8 dB while at a modal overlap index as low as 1.9, corresponding to a frequency of 264 Hz, the difference is less than 1.6 dB. The results of these tests suggest that the one-third-octave-band decay method is quite sufficient for the qualification of a reverberant room with a modal overlap index of 5 or greater for tone-power measurements. The results of these tests also suggest that any room can be qualified for the measurement of sound power in a tone if it is possible to substitute the mouth of an impedance tube and horn for the source whose sound power is to be measured. The required apparatus is simple and the measurements are easily performed.
Subject Classification: [43]55.65; [43]85.20, [43]85.24.
Numerical prediction of echograms and of the intelligibility of speech in rooms
Authors: Santon François 
Published: October 2005

An improved method for the estimation of speech intelligibility in rooms prior to construction is described which takes into account the directional distribution of the echoes and is based on the concept of received energy being partitioned into useful and disturbing energies. Laboratory experiments are described which substantiate the applicability of the method. The possibility of computing the energy accumulated versus time by specified receivers in a room is discussed broadly; it is shown by numerical example that the image method and the ray method give closely similar results. Numerical computations based on the ray method are compared with experimentally derived energy accumulation curves for two different rooms and are found to agree substantially. Since the computational method also predicts the directional distribution as well as the time accumulation of received sound, it is conjectured that accurate predictions of speech intelligibility taking directionality of echoes into account may be made from architectural plans and from a knowledge of surface absorption coefficients.
Subject Classification: [43]55.20, [43]55.40; [43]70.35.
Creating an acoustic synthetic aperture in the ocean
Authors: Williams Ross E. 
Published: October 2005

A synthetic aperture experiment was conducted using a ship-towed source and midwater receiving hydrophones buoyed upward 4700 and 8000 ft from bottom moorings in a depth of 17 200 ft. The tows were conducted along straight lines perpendicular to the direction to the hydrophones at ranges of 58, 93, 128, 198, and 268 NM. A cw signal at 400 Hz and a swept FM signal between 350 and 450 Hz were transmitted continuously during the tows. Although major difficulties were encountered in maintaining straight tows in the presence of surface swells, it was possible to construct a number of synthetic apertures for the 400-Hz transmissions on an intermittent basis. The lengths of these apertures extended to 1/2 NM and more, corresponding to coherence time intervals of up to 7 1/2 min in the ocean.
Subject Classification: [43]30.20; [43]60.30.
Vibrational and rotational relaxation of water vapor by water vapor, nitrogen, and argon at 500 °K
Authors: Keeton Roy G. , Bass H. E. 
Published: October 2005

Ultrasonic absorption has been measured in mixtures of H2O with 15%, 35%, and 55% Ar and N2 at 500 °K. The classical absorption was subtracted from the measured values and the remainder was analyzed in terms of parallel vibrational and rotational relaxation. By extrapolating to 100% H2O, the rate of self deactivation was found to be (2.0 ± 0.4) × 108 sec−1 atm−1 for vibration and (8.3 ± 0.5) × 108 sec−1 atm−1 for rotation. Extrapolation to 0% H2O yields a rate of (4.0 ± 2.0) × 106 sec−1 atm−1 for H2O vibrational deexcitation by N2 or Ar. The isothermal–isometric rotational relaxation time for H2O in one atm of Ar was found to be (1.2 ± 0.2) × 10−9 sec. These results at 500 °K are compared with other work at higher and lower temperatures in order to form a basis for extrapolating to room temperature.
Subject Classification: [43]35.20, [43]35.35.
Interaural phase discrimination for combination tone stimuli
Authors: Zurek Patrick M. , Leshowitz Barry H. 
Published: October 2005

A binaural interaction between the combination tone 2f1—f2 generated by two primary tones and a pure tone of the same frequency was demonstrated in an investigation of interaural phase discrimination. Sensitivity to changes in interaural phase was comparable to that obtained with pure tone stimuli. In a second experiment, combination tones of the same frequency, but different order, generated by independent pairs of primary tones presented to the two ears, were also shown to be easily lateralized. Finally, observers were able to discriminate changes in the phase of a low-frequency combination tone generated by high-frequency primaries, which themselves could not produce a binaural interaction based on phase. The results are in accord with the prevailing conception of combination tones as being functionally identical to spectral components in the stimulus.
Subject Classification: [43]65.56, [43]65.62, [43]65.60.
TTS from neighborhood aircraft noise
Authors: Ward W. Dixon , Cushing E. Marion , Burns Edward M. 
Published: October 2005

In an attempt to determine the effect on the auditory threshold of the worst ’’neighborhood’’ exposure to aircraft noise that can reasonably be expected, tape-recorded overpasses, both landings and takeoffs, were reproduced at 111 dBA peak level in a reverberant room. Six-hour exposures to landings or takeoffs at the rate of 1 per 1.5 or 3 min were given to one of two groups of five normal listerners. The mean TTS2 (temporary threshold shift 2 min after exposure) did not reach 5 dB at any frequency in any condition. The possibility of hearing damage from such exposures is therefore judged to be remote, despite the fact that the 8-h ’’equivalent levels’’ of these exposures are as high as 95 dBA. The importance of interruptions in reducing risk is emphasized.
Subject Classification: [43]65.66; [43]50.55, [43]50.70.
On the recovery of physical dimensions of stimuli, using multidimensional scaling
Authors: Morgan Byron J. T. , Woodhead Muriel M. , Webster John C. 
Published: October 2005

The results of three confusion experiments (acoustic presentation, visual presentation, and combined acoustic and visual presentation of the stimuli), involving artificial sounds constructed from four physical parameters, are analyzed using nonmetric multidimensional scaling (MDS). It appears that just three of the physical parameters are important in the confusions of these sounds in all three cases. The parameter sets used in the combined and visual presentation experiments were identical and differed from that used in the acoustic presentation experiment.
Subject Classification: [43]65.75, [43]65.58.
Ultrasonic production of reversible changes in the electrical parameters of isolated frog skin
Authors: Coble A. J. , Dunn F. 
Published: October 2005

Isolated frog skin was irradiated with 1-MHz noncavitating focused ultrasound, intensity range 1–100 w/cm2, in an adaptation of the Üssing chamber providing continuous perfusion of the specimen. The electrical parameters of the skin, viz., the membrane potential (MP) and the short circuit current (SCC), were monitored continuously before, during, and after the acoustic exposure. The magnitudes of the ultrasonically induced changes, in both parameters, were proportional to the acoustic intensity, though the MP decreased while the SCC increased. Unlinking of the two electrical parameters occurs in that their time courses in response to the ultrasound differ, i.e., the SCC increases continuously for exposures of 0.5 sec and longer while the MP reaches its maximum within 0.5 sec and is not altered with increased duration of exposure.
Subject Classification: [43]80.40; [43]35.75.
Acoustic systems containing curved duct sections
Authors: Rostafinski W. 
Published: October 2005

The analysis of waves in bends in acoustical ducting of rectangular cross section is extended to the study of motion near discontinuities. This includes determination of the characteristics of the tangential and radial components of the nonpropagating modes. It is established that attenuation of the nonpropagating modes strongly depends on frequency and that, in general, the sharper the bend, the less attenuation may be expected. Evaluation of a bend’s impedance and of impedance generated reflections is also presented in detail.
Subject Classification: [43]20.45, [43]20.40.
Acoustic power of a moving point source in a moving medium
Authors: Cole J. E. , Sarris I. I. 
Published: October 2005

Two expressions for the acoustic power output of a moving point source in a moving acoustic medium are obtained. Each is based on a different definition cited in the literature for the average energy-flux vector in an acoustic medium that is in uniform motion. One of the power expressions is shown to provide results which are unreasonable.
Subject Classification: [43]20.55, [43]20.60; [43]28.60.
Comments on ’’Diffuse sound reflection by maximum length sequences’’ [J. Acoust. Soc. Am. 57, 149–150 (1975)]
Authors: Moharir P. S. 
Published: October 2005

Some improvements are suggested to Schroeder’s scheme [J. Acoust. Soc. Am. 57, 149–150 (1975)] of achieving diffuse sound reflection in concert halls.
Subject Classification: [43]55.20, [43]55.40.
Sonoluminescence from water containing dissolved gases
Authors: Young F. Ronald 
Published: October 2005

The sonoluminescence from 17 different gases dissolved in water was measured. The results show an inverse relation with the thermal conductivity of the gas. The thermal conduction losses of the gas in the cavitation bubble during its rapid collapse are considered, and an expression found for the final temperature of the gas. The sonoluminescence results for the five rare gases studied agreed with this theory.
Subject Classification: [43]35.68, [43]35.32.
Vibratory response of laminated cylindrical shells embedded in an acoustic fluid
Authors: Harari A. , Sandman B. E. 
Published: October 2005

The equations of motion for a three-layered cylindrical shell are derived. The thickness and material properties may be different for each layer. Dissipative materials may also be considered. The solution for a simply supported cylindrical shell excited by a time-harmonic load is obtained in vacuum and in a fluid-acoustic medium. The response of the shell and the corresponding acoustic pressure field is found and illustrated for a specific configuration.
Subject Classification: [43]40.26; [43]20.60.
Mechanical parameters of hearing by bone conduction
Authors: Khanna Shyam M. , Tonndorf Juergen , Queller Judith E. 
Published: October 2005

A new, powerful, magnetostrictive bone conduction (BC) vibrator is described. At low output levels, it has a wide frequency range (5 Hz to above 20 kHz), and for midfrequencies undistorted outputs reach up to 50 g in terms of acceleration. BC thresholds and SL’s (the latter determined by AC/BC cancellations) were measured with this vibrator. Both varied with contact force, but much more markedly with contract area, in unoccluded as well as in occluded ears. Sound attenuation boxes, after von Békésy, were used in the unoccluded state. Results of the AC/BC cancellations permitted determination of the external-ear and the inner-ear BC components. With the ear unoccluded, variations with contact area (and/or force) were mainly related to changes of the inner-ear responses, but with the ear occluded, they were related to those of the BC-generated sound pressures in the ear canal for f&lt;2 kHz. At AC and BC threshold, SPL’s in the ear canal had identical values and did not vary with contact area or force for f&lt;2 kHz. For a comparable small contact area, BC acceleration thresholds were similar to those specified in ANSI S3.13−1972. For larger contact areas, however, they were lower, by as much as 25 dB, at some frequencies. These results indicate that acceleration is not a valid indicator of the BC input to the skull.
Subject Classification: [43]65.22, [43]65.80, [43]65.64.
Comment on ’’Interaural alternation, information load, and speech intelligibility’’ [J. Acoust. Soc. Am. 57, 1219–1220 (1975)]
Authors: Speaks Charles 
Published: October 2005

Wingfield and Wheale [J. Acoust. Soc. Am 57, 1219–1220 (1975)] claim that detrimental effects of interaural alternation on speech intelligibility may not occur unless the listener is placed under some ’’load’’ that is imposed by either a shadowing response, greater linguistic complexity in the message, or a higher input rate of speech. These three sources of load do not appear to be of equal importance. Further, because of the complex interactions among the three sources, based on their results and those of previously reported experiments, it is hazardous to conclude that intelligibility is affected adversely by any ’’critical’’ rate of interaural alternation.
Subject Classification: [43]70.30, [43]70.35.
Reply to ’’Comments on ’Sabine’s reverberation time and ergodic auditoriums’ ’’ [J. Acoust. Soc. Am. 60, 506–508 (1976)]
Authors: Joyce W. B. 
Published: October 2005

Gomperts and I apparently maintain our differences on a number of points which are summarized.
Subject Classification: [43]55.20, [43]55.30, [43]55.55.
Energy spectrum analysis: A model of echolocation processing
Authors: Johnson Richard A. , Titlebaum Edward L. 
Published: October 2005

Previous analyses of echolocation have suggested that correlation-equivalent processing might be used in certain cases. A frequency domain approach based on energy spectrum analysis of the signal and its echoes combined is proposed as the processing mechanism for echolocation. It is a generalized wide-band mechanism and can account for the large diversity of wide-band signals known to be used for orientation. Neurobiological investigations neither confirm nor deny any specific kind of correlation equivalent processing, but this proposal offers the first frequency domain correlation-equivalent possibility. A review of time separation pitch reveals that an identical analysis has been used to explain that phenomenon. Extensions of the model can explain many of the phenomena observed in echoloction.
Subject Classification: [43]80.50, [43]80.60; [43]60.40; [43]65.62, [43]65.68.
Acoustical effects in panel response to supersonic turbulence
Authors: Pope Larry D. 
Published: October 2005

Acoustical coupling of a turbulence-excited panel and a supersonically moving fluid is investigated. Response of a panel with a single rib discontinuity is considered. Radiation from the panel into the fluid induced by a uniform line force is investigated and the line admittance of the panel in the presence of supersonic flow is obtained. Numerical results are presented for the line admittance and for the ribbed and unribbed infinite panel response. A relation is given which upon integration will yield the radiation damping of a finite panel (radiation into the supersonic flow).
Subject Classification: [43]40.35; [43]28.65; [43]20.60.
Subharmonic pitches of a pure tone at low S/N ratio
Authors: Houtgast T. 
Published: October 2005

2AFC scores were obtained on 50 untrained subjects who had to respond to a 3% increment or decrement of the fundamental frequency of two successive signals. The first signal in each trial was a reference, containing six harmonics of 200 Hz. Main variables were the number of harmonics of the second signal in a trial (either 3, 2, or 1) and the presence or absence of continuous background noise. Low scores were observed in the absence of the noise (typically 65% for the 3- and 2-component signals, and virtually 50% for the 1-component signals), whereas in the presence of the noise much higher scores were observed (typically 90% and 80%, respectively). The results indicate that background noise has great impact on the perceptibility of a ’’low pitch’’ related to the fundamental frequency, even more so than the number of components presented (within the range of three, two, or one components): at a low S/N ratio, even a single harmonic may give rise to the perception of a subharmonic low pitch. Subsequent experiments with three trained subjects indicated that this potential of a single pure tone to evoke a subharmonic pitch deteriorates for harmonic numbers of about n=7 to 11. The theoretical implications of these subharmonic pitches of a pure tone to pitch perception in general are discussed.
Subject Classification: [43]65.54, [43]65.75, [43]65.35.
Gap detection with three auditory events—a single-channel process
Authors: Williams Kendrick N. , Elfner Lloyd F. 
Published: October 2005

Temporal resolution of a silent interval (gap) imbedded in a three-tonal-pulse train was investigated. Two frequencies were alternated in a three-event array where the gap could appear between the first and second or second and third auditory event. Frequency and gap position effects were systematically explored using a temporal two-interval forced-choice paradigm and a modified tracking procedure. Gap detection was found to vary as a function of antecedent event duration and signal-comparison stimulus similarity. Indications of a filter process similar in bandwidth to the empirical critical band was found in fully correlated signal-comparison stimulus conditions. Obtained results are consistent with fixed-filter signal-envelope detection models found in the simultaneous and forward-masking literature.
Subject Classification: [43]65.75, [43]65.68.
Digital analysis of laryngeal control in speech production
Authors: Flanagan J. L. , Rabiner L. R. , Christopher D. , Bock D. E. , Shipp T. 
Published: October 2005

Physiological measurements are made directly on human talkers to determine several dynamic laryngeal functions. The functions are control variables in a speech synthesizer which utilizes acoustic models of the vocal cords and vocal tract. The functions are measured simultaneously and recorded on multichannel FM tape. They are the time variation of vocal-cord (glottal) opening (Ag); the electromyographic (EMG) potentials of three laryngeal muscles−−posterior crico-arytenoid (PCA), interarytenoid (IA), and crico-thyroid (CT); the subglottal air pressure (Ps); the speech output sound pressure waveform (P); and timing pulses from a digital clock. Preliminary data for ten utterances by a man are digitized by a multiplexed A/D converter on a DDP−516 computer, and the results are stored in disk file for analysis. Bandwidth of the multitrack FM playback is 2800 Hz. Each function is sampled at 6250 sec−1 and quantized to 16 bits. Digital filtering is applied to remove dc offsets and enhance information features. The acoustic functions (Ag, Ps, and P) are submitted to programmed pitch analysis. The results show how voice periodicity can be manifested differently at the glottal and sound-output levels. A typical instance is vocal-cord vibration throughout the occluded phase of a voiced stop consonant. The EMG functions are analyzed by computing short-time energy. The results are correlated with voicing onset/offset and with voice pitch. PCA energy is shown to be correlated with voicing offset, and anticipatory to it by about 20–30 msec. IA energy is shown to be correlated with voicing onset, and anticipatory to it by about 40–50 msec. CT energy is found to be nearly directly correlated with the frequency contour for voice pitch. Direct utilization of these physiological parameters for speech synthesis is suggested.
Subject Classification: [43]70.20, [43]70.60.
Jet-drive mechanism in organ pipes
Authors: Fletcher N. H. 
Published: October 2005

The analysis given by Elder [J. Acoust. Soc. Am. 54, 1554 (1973)] of the mechanism of interaction between a time-varying air jet flow velocity and a resonant organ pipe is extended to deal with the case in which a jet of fixed flow velocity is deflected to cut a sharp pipe lip. Similar terms arise in the analysis but the nonlinearities are less important than in Elder’s case. The generation of higher transverse pipe modes by the jet asymmetry is considered and it is concluded that such modes may play a significant part in coupling ordinary pipe modes to pipe-wall vibrations.
Subject Classification: [43]75.60.
Spatial correlation of wind-generated noise at very low frequencies
Authors: Wilson James H. 
Published: October 2005

Analysis of the ambient-noise horizontal directionality data from a recent environmental acoustic exercise indicates that wind-generated noise at 10 Hz is spatially correlated over large apertures. The noise levels measured by a large aperture, linear towed array were highest near broadside during high-wind conditions. Spatially correlated wind-generated noise arriving from the sea surface directly above the array is offered as a possible explanation and is consistent with results of previous wind-noise experiments. In the limiting case of very high wind speeds (?35 knots), the array response measured for this nearfield effect closely approximated the farfield broadside beam pattern at 10 Hz. At lower wind speed, the array response was wider near broadside. This implies that the spatial correlation of wind-generated noise at 10 Hz becomes greater as the wind speed increases.
Subject Classification: [43]28.20, [43]28.65; [43]50.80.
Ambient sea noise in waters near Australia
Authors: Cato D. H. 
Published: October 2005

Ambient sea noise has been measured at 40 positions in mainly tropical waters near Australia: in the Indian Ocean; the Arafura and Timor Seas; and in the Coral and Tasman Seas (Pacific Ocean). Wind-speed dependence was observed at all frequencies of measurement from 22 to 5000 Hz. At hydrophones suspended at depths between 8 and 25 m, the wind- dependent noise appeared to be independent of bottom depth which varied from 26 to 6700 m. The rate at which wind-dependent noise increased with increasing wind speed was found to be significantly less than has been observed in the North Atlantic Ocean. Non-wind-dependent noise, observed at frequencies below 250 Hz, varied by about 10 dB within a particular sea and by up to 20 dB between seas, and could be broadly related to the relative shipping densities and propagation conditions in the individual seas. In the shallow Arafura and Timor Seas north of Australia, there is evidence that noise of distant shipping is not a significant component of the ambient noise. A model of traffic noise in the Tasman Sea predicts levels in agreement with observed noise levels.
Subject Classification: [43]30.70.
Use of phase measurements for arrival-time extraction of overlapping sinusoidal signals in shallow water
Authors: Fjell Per O. 
Published: October 2005

The use of phase measurement for sinusoidal signal arrival-time extraction of overlapping signals subjected to multipath conditions in shallow water is considered. The phase-measurement method is applied to signal data from a research cruise. The method does not give convincing results. For distances greater than 10 000 m the results are negative. The results obtained are strongly dependent on the sound velocity profile. The signal pulse length was a very important parameter in the results. The optimal pulse length was shown to be greater than 10 msec and less than 100 msec regardless of the hydrophone depth for the two depths investigated.
Subject Classification: [43]30.20; [43]60.30.