• Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Journal of the Acoustical Society of America

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

Feb 1967

Volume 41, Issue 2, pp. 277-537

Page 1 of 2 Pages Next Page | Jump to Page

Perturbations of Synthetic Orchestral Wind‐Instrument Tones

William Strong and Melville Clark, Jr.

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 277-285 (1967); (9 pages) | Cited 3 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The relative significance of spectral and temporal envelopes for the synthesis of orchestral wind‐instrument tones was evaluated by exchange of spectral and temporal envelopes among the wind instruments, by creation of artificial spectral envelopes, and by perturbation of the spectral envelopes. It was found that, for the oboe, clarinet, bassoon, tuba, and trumpet, where the spectral envelope is unique as regards the frequency of its maximum and the range in which the instrument is normally played, this envelope predominates in aural significance over the temporal envelope. Where the spectral envelope is not unique—as for the flute, trombone, and French horn the spectral envelope is equal or subordinate to the temporal one in aural significance. Interfamily confusions are fewer in those cases where the spectral envelope is of predominant importance: about 14% for the clarinet, oboe, bassoon, and tuba anti about 25% for the flute, trumpet, trombone, and French horn. The ratio between identification probabilities of synthetic and natural tones is 0.97 for the oboe, 0.90 for the clarinet, 0.86 for the French horn, 0.82 for the bassoon, 0.77 for the flute, 0.75 for the trumpet, 0.69 for the tuba, and 0.62 for the trombone.

Effects of Transmission Delay and Access Delay on the Efficiency of Verbal Communication

Robert M. Krauss and Peter D. Bricker

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 286-292 (1967); (7 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
Two experiments were performed to investigate the effects of transmission delay and access delay, respectively, on the efficiency with which speakers verbally encoded information for transmission in a two‐person communication task. Both experiments employed echo‐free four‐wire voice circuits in an attempt to isolate each delay effect and to avoid the delayed echo effect found in commercial circuits. In the first experiment, three values of pure roundtrip transmission delay were used: no delay, 0.6 sec, and 1.8 sec. Using 14 pairs of male subjects in each condition, it was found that, whereas 1.8 sec of transmission delay deleteriously affected the efficiency of communication, subjects performed as efficiently using the 0.6‐sec delay circuit as with no delay. In the second experiment, three values of access delay were used: no delay, 0.25 sec, and 1.8 sec. Ten pairs of male subjects and 10 pairs of female subjects were run in each condition. The effect of access delay was found to be different for the two sexes. Access delay of 1.8 sec had a greater effect on males than on females, whereas at 0.25‐sec delay female performance was impaired slightly and male performance not at all. With no delay, male and female performance did not differ. These results are supported by data based on subjects' responses to a postexperiment questionnaire. The findings are discussed in terms of their relevance to problems encountered in two‐way voice communication over long transmission paths.

Cepstrum Pitch Determination

A. Michael Noll

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 293-309 (1967); (17 pages) | Cited 6 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The cepstrum, defined as the power spectrum of the logarithm of the power spectrum, has a strong peak corresponding to the pitch period of the voiced‐speech segment being analyzed. Cepstra were calculated on a digital computer and were automatically plotted on microfilm. Algorithms were developed heuristically for picking those peaks corresponding to voiced‐speech segments and the vocal pitch periods. This information was then used to derive the excitation for a computer‐simulated channel vocoder. The pitch quality of the vocoded speech was judged by experienced listeners in informal comparison tests to be indistinguishable from the original speech.

Numerical Model of Coarticulation

Sven E. G. Öhman

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 310-320 (1967); (11 pages) | Cited 8 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The essential features of the coarticulation properties of Swedish dental stops in vowel‐consonant‐vowel contexts can be described by the formula s(x; t)  =  v(x; l)+k(t)[c(x) − v(x; t)]wc(x), where x represents the longitudinal distance between lips and glottis and s(x; t) denotes the shape of the vocal tract at some instant of time, t, during the vowel‐consonant vowel utterance. The vowel component, v(x; t) is a linear combination of the three “extreme” shapes of the vowels /i/, /a/, and /u/ with weights that vary as functions of time. The consonant is represented by c(x), an ideal target shape, and wc(x), a so‐called coarticulation function. A time varying factor k(t) represents the degree of excursion of the consonantal gesture. Vocal tract shapes measured from x‐ray motion pictures of a set of Swedish vowel‐consonant vowel utterances compare well with shapes generated by the formula. This result is consistent with our earlier conclusions about coarticulation, viz., that the vowel and consonant gestures are largely independent at the level of neural instructions.

Analysis of Acoustic‐Emission Strain Waves

D. M. Egle and C. A. Tatro

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 321-327 (1967); (7 pages) | Cited 4 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
An acoustic‐emission loading and detection system is described and the detection system's harmonic response to both longitudinal and flexural waves is evaluated. Photographs of acoustic‐emission response pulses are presented, and it is shown that the flexural waves are of considerable importance in describing the detection systems's response to the acoustic‐emission source pulse. An estimate indicates that the energy of the flexural part of one acoustic‐emission pulse is two orders of magnitude greater than the energy of the longitudinal part.

Transient Electron‐Inertia Field Produced by a Strain Pulse

J. D. Kennedy and C. W. Curtis

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 328-335 (1967); (8 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
Conduction electrons, owing to their inertia, should move relative to an accelerated metallic lattice as they would in a stationary conductor if subjected to an electric field equal to the mass/charge ratio of an electron times the acceleration of the lattice. Since a strain pulse produces a transient acceleration, it should be accompanied by an electron‐inertia field of this type. To demonstrate this effect, a torsional strain pulse was used to produce rotational acceleration of an insulated metal ring, and the electromagnetic signal, generated by the ring during acceleration, was detected by a pickup coil connected to an oscilloscope. The theory of a strain‐induced electron‐inertia effect is discussed, and calculations are carried out for comparison with measurements. Reasonable agreement between measurement and prediction serves to identify electron inertia as the cause of the signal.

Use of Thick Transducers to Generate Short‐Duration Stress Pulses in Thin Specimens

Ronald G. Peterson and Moshe Rosen

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 336-345 (1967); (10 pages) | Cited 2 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
It is shown how the pulse‐echo method for determining sound velocities and acoustic attenuation can be applied to thin specimens by generating short stress pulses with thick transducers. The method is described in conjunction with its use in the observation of phase transformations in which both transit‐time data and attenuation measurements are used to determine the mechanism and kinetics of the transformation. Results are shown for the β → α a phase transformation in high‐purity plutonium.

Reflection of Wave Trains in Semi‐Infinite Plates

Peter J. Torvik

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 346-353 (1967); (8 pages) | Cited 22 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
A method for using the well known modes of vibration for the infinite plate as elements of an expansion applicable to semi‐infinite plates is given. The method is employed to study the reflection of an infinite train of waves from the free edge of an elastic plate. The incident train of waves induces other, nonpropagating, modes. As has previously been discovered, a resonance may occur in such a mode that will increase the portion of the plate for which the evanescent modes affect the stress distribution. Above a critical frequency, a transfer of energy from one propagating mode to another occurs during the reflection. Generally, energy brought to a free edge by waves of one wavelength will depart in wave trains of several different wavelengths. The presence of a mode which, for a limited range of frequency, carries energy in a direction opposite to the motion of the waves is confirmed. Some observations are made about necessary restrictions in an extension of St. Venant's principle to dynamic loadings.

Improved Transfer Standard for Vibration Pickups

E. Jones, D. Lee, and S. Edelman

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 354-357 (1967); (4 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
This paper describes a vibration transfer standard designed to provide comparison calibrations of pickups with minimum degradation. Features of the design are the use of a ceramic housing of a stiff, light, lossy material; provision of a means for evaluating the quality of the motion by the use of three integral accelerometers oriented parallel to the nominal direction of motion; and design of the geometry to minimize differences in motion between the pickup being calibrated and the standard. The useful frequency range is 10–10 000 Hz.

Transient Response of an Elastic Shell in Plane Strain

L. M. Keer, J. F. Fleming, and G. Herrmann

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 358-368 (1967); (11 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF


See Also: Erratum

Show Abstract
The dynamic response of a circular, elastic shell in plane strain, when given an impulsive radial load, is studied. Inextensional bending is assumed and approximate solutions are obtained for the behavior at the wavefronts and for some time after the wave has passed. The method of Friedlander as applied by Payton to shells is used to study the wave propagation for relatively long times, and the bending‐moment distribution is obtained.

Resonance of a Bubble on an Infinite Rigid Boundary

J. E. Blue

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 369-372 (1967); (4 pages) | Cited 2 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The resonant frequency of a bubble attached to a rigid infinite plane in an infinite incompressible liquid was determined theoretically taking into consideration the angle of contact of the bubble with the plane. The resonant sizes at 33 and 36 kHz were determined experimentally by plotting the relative acoustic pressure (required to cause bubbles to jump one bubble diameter horizontally) versus the bubble radius and were found to be 76 and 67 μ, respectively. The experimental resonant sizes were found to be in good agreement with the theoretical resonant sizes. A small minimum on the plot can possibly be explained by using a Mathieu equation.

Acoustic Turbulent Water‐Flow Tunnel

George F. Carey, John E. Chlupsa, and Howard H. Schloemer

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 373-379 (1967); (7 pages) | Cited 1 time

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The acoustic turbulent water‐flow tunnel designed and constructed at the U. S. Navy Underwater Sound Laboratory has a clear plastic‐pipe test section (3½‐in. i.d.) through which water is pumped at centerline velocities ranging from 9 48 knots. Noise‐reduction techniques have prevented pump and piping noises from entering the test section through either structural or fluid paths. Measurements at centerline velocities between 9 and 48 knots with flush mounted hydrophones at several longitudinal spacings show that the ratio of convection velocity to centerline velocity ranges from 0.86 to 0.61. The curve of maximum space‐time correlation in frequency bands versus hydrophone spacing in wavelengths is in good agreement with other published results. Frequency spectra measured from 200–10 000 Hz coincided when nondimensionalized with respect to centerline velocity and boundary‐layer thickness. When corrected for hydrophone size, the spectral curve was similar to those reported for turbulent airflow and rising and falling bodies in water.

Echoes from Hollow Aluminum Spheres in Water

K. Jerome Diercks and R. Hickling

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 380-393 (1967); (14 pages) | Cited 2 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
Recorded farfield echoes from precision hollow aluminum spheres in water, with different shell thicknesses and with either water or air in the hollow interior, are compared with calculated echoes. Steady‐state echoes are investigated over a ka range of from 6 to 27, and individual pulsed echoes at ka = 20. Excellent verification is obtained for the features predicted by the theory. It is shown that the echoes are sensitive to changes in the elastic properties of the shell, particularly when the shell is thin. The experiments showed, moreover, that the echoes are dependent on the orientation of the sphere. This is due presumably to small asymmetries in the structure and properties of the shell and emphasizes again the strong interrelation between sonar echoes and the nature of the material in the target.

Computation of Farfield Radiation Patterns by Use of a General Integral Solution to the Time‐Dependent Scalar Wave Equation

Horace G. Ferris

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 394-400 (1967); (7 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The computation of farfield radiation patterns by use of a general integral solution to the time‐dependent scalar wave equation is considered. The use of this theorem in this connection appears to offer advantages that may have been overlooked. In particular, the general theorem is capable of interpretation in terms of an analogous network of linear systems whose inputs are the nearfield measured pressures and whose summed output is the desired farfield pressure. Moreover, the general theorem is valid for signals which are general functions of the time, including noise signals, as well as for signals having only a single frequency component. It may accordingly be applied to a much wider class of signals than may the familiar Helmholtz formula or the Green's formula, which have been used as the basis for most farfield computations in the past. The network interpretation of the general theorem is discussed in some detail and the forms of the network response function for both a plane and a spheroidal surface of measurement are given.

Long‐Range Sound Propagation in the South Tasman Sea

A. C. Kibblewhite and R. N. Denham

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 401-411 (1967); (11 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
Experiments on long range propagation of sound in the South Tasman Sea were carried out by the New Zealand Naval Research Laboratory in July 1963 and April 1964. These appear to provide the first examples of RSR‐type propagation in the southern hemisphere; convergence zones are observed with a spacing of from 32 to 33 nautical miles. In addition, changes in the characteristics of propagation may be associated with an oceanic front, the “subtropical convergence,” which is present in this area. North of this hydrological boundary, the convergence zones are much more sharply defined, and the attenuations are less than on the southern side.

Nearfield Pressure For an Infinite Phased Array of Circular Pistons

V. Mangulis

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 412-418 (1967); (7 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The nearfield pressure and the radiation impedance for an infinite phased array of circular pistons (with the same velocity magnitude) in a rigid plane baffle are calculated. A slowly convergent infinite series expression for the pressure, obtained from the appropriate Green's function, is transformed by the use of Poisson's sum formula into a more rapidly convergent infinite series expression. Numerical results are presented. A rough estimate of the location and value of the maximum pressure in the nearfield is obtained under certain restrictions. The radiation impedance of a piston in the infinite array agrees well with the average radiation impedance of a piston in a large finite array.

Comparison of Curvilinear and Linear Profile Approximation in the Calculation of Underwater Sound Intensities by Ray Theory

Melvin A. Pedersen and David F. Gordon

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 419-438 (1967); (20 pages) | Cited 2 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
This paper presents the forms and curve‐fitting techniques necessary for the calculation of ray‐theory intensities for a curvilinear profile approximation in which continuity of slope as well as velocity is preserved. Using the Epstein profile as a control, this approximation is compared with various approximations that have slope discontinuities. The continuous‐slope approximation does not display the artificial effects inherent in approximations with slope discontinuities, such as the introduction of spurious caustics, the omission of real caustics, and the generation of unrealistic regions of low intensity. However, artificial‐layering effects in the form of infinite rates of change in intensity appear in the computations for the continuous‐slope approximation because of discontinuities in the second derivative. The use of a new profile approximation that can preserve continuity of an arbitrary number of derivatives is suggested.

DIMUS Processing with Seven‐Element Active‐Sonar Arrays

Winslow R. Remley, Donald V. E. Upton, and Donald L. Del Giorno

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 439-444 (1967); (6 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The aural detectability of a seven element DIMUS array for active sonar has been studied experimentally. The array was simulated with sonar data recorded at sea. It was found that a DIMUS array consisting of as few as seven elements can be effectively used. Doppler detectability is preserved. If the interference consists of reverberation from a pulse having a sinusoidal amplitude distribution, the clipping loss is about 2.5 dB for small signal‐to‐reverberation levels. This loss is independent of the bandwidth of the transmitted pulse. If the interference is local noise, the clipping loss is less than 1 dB. It was also found that when equal pulse lengths are used, the detectability of slow targets is much greater with broad‐band transmission pulses than with conventional Continuous‐wave pulses in reverberation‐limited conditions. The improvement in detection with the broad‐band pulses was preserved with DIMUS.

Criterion under Which the Standard Detector Is Optimal

Arthur Shapiro

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 445-447 (1967); (3 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
This paper is concerned with the detection of a narrow‐band signal using two hydrophones. Specifically, it addresses itself to the problem of finding the “optimal” linear combination of sample spectra, cospectrum, and quadrature spectrum to use as a detection‐test criterion. The optimal detector is defined here as the one that maximizes the average probability of detection for given probability of false alarm and given observation time, where the average is taken over all possible noise‐coherence and noise‐phase‐difference conditions. It is shown that, under not unrealistic conditions, the optimal detector, among all those that are linear in the sample spectra and the co‐ and quadrature spectra, is the one that adds the outputs of the detectors and squares the result. In other words, there are strong indications that if one restricts oneself to detectors of the form given, the best one can do, on the average, is to continue doing what is currently being done.

Frequency Discrimination following Exposure to Noise

John F. Brandt

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 448-457 (1967); (10 pages)

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
Measures of threshold and frequency discrimination were obtained at 1000, 2000, and 4000 Hz before and after exposure to wide‐band noise. Two test‐stimulus SPL's (sound‐pressure levels) were used during the postexposure discrimination measures such that stimuli were presented at 10 or 40 dB SL (sensation level) re TTS3 (temporary threshold shift). The SPL remained constant throughout recovery during each experimental session. When test stimuli were equated in terms of SL, no differences between pre‐ and post‐exposure jnd's (just‐noticeable differences) were noted at 40 dB SL or greater at any frequency. At low stimulus SL's (10–20 dB), however, a differential effect on the jnd occurred owing to noise exposure that was not explainable in terms of TTS. At 4000 Hz (where maximum TTS occurred), there was little difference between pre‐ and postexposure jnd's. At 2000 Hz, a 10% impairment in the jnd existed in the latter stages of recovery. At 1000 Hz (no TTS), the postexposure jnd's were about 40% greater than pre‐exposure jnd's and independent of recovery time. A paradox thus exists at low SL's between amount of threshold shift and frequency discrimination.

Auditory Spectral Filtering and Monaural Phase Perception

J. L. Goldstein

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 458-479 (1967); (22 pages) | Cited 15 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The fundamental relation of limited auditory frequency resolution to mortar phase perception is studied. Old and new results are discussed for experiments employing sinusoidally amplitude‐modulated (AM) carrier tones and quasi‐frequency modulated (QFM) carrier tones, which are related by a phase transformation. One experiment concerns AM and QFM modulation thresholds. A second experiment considers the quality differences between AM and QFM. Both experiments show that phase effects disappear for stimulus bandwidths that exceed a value roughly proportional to the critical band at the carrier frequency. The proportionality factor depends upon carrier level and differs greatly between experiments. A unified psycho‐physical account is given with a model consisting of a quasilinear bandpass analyzing filter followed by ideal envelope detection, and concluding with either a peak‐to‐minimum or peak‐threshold decision. Parameter values in the model are evaluated from the phase‐perception data, and these values support the assumptions that underlie the model. It is shown that the critical‐bandlike experimental data do not provide a measure of the commonly conceived critical band. Rather, the critical‐band scale merely normalizes the analyzing‐filter parameters. This work indicates that the model employed offers wider application.

Stimulus‐Oriented Approach to Detection Re‐Examined

Lloyd A. Jeffress

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 480-488 (1967); (9 pages) | Cited 7 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The present paper is a reexamination of some of the conclusions of an earlier one. It is motivated by some new insights resulting from attempts to replicate experiments with human observers, through the use of an electrical model of the auditory system. It is concerned primarily with the effect of signal duration on detection in the presence of a continuous masking noise. The model, of those tried, that best fits human performance consisted of a bandpass filter obtained by subtracting the output of a 500‐Hz sharp‐cutoff, low‐pass filter from another having a cutoff of 525 Hz. The filter was followed by a linear half‐wave rectifier and it, in turn, by an integrator having a 100‐msec decay time. The integrator can be thought of as a device that takes a running average of its input. The probability density distributions for N and SN yielded by the model lie between the Rayleigh Rice distributions on the one hand and a pair of normal distributions of unequal variance on the other. The exact shape of the two distributions depends upon both the bandwidth of the filter employed and the time constant of the averager.

Effects of Stimulus Duration on the Detection of Sinusoids Added to Continuous Pedestals

Barry Leshowitz and David H. Raab

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 489-496 (1967); (8 pages) | Cited 5 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
The effect of stimulus duration on the detection of sinusoids added to continuous pedestals was investigated in two studies. Gated 1000‐Hz sinusoids were added in phase with continuous pedestals in the presence of a steady background noise at durations between 10 and 500 msec. Plots of signal intensity necessary for approximately 75%‐correct detections as a function of duration revealed enhanced detectability and an intensity duration reciprocity factor of 14 dB per log unit of time. In the second experiment, signal energy was held constant as duration of the probe was varied between 10 and 100 msec, and the proportion of correct responses was measured in a two‐interval forced‐choice procedure. Marked improvement in detectability obtained as signal duration was increased. When increment energy was held constant, discriminability remained unchanged in the face of a 10‐dB decrease in signal energy. After correcting an energy‐detection model for internal noise, the model accurately predicted the proportion of correct responses. Finally, it is argued that a description of detection data in terms of increment energy renders results obtained with pedestals simpler and more understandable.

More on the Detection of One of M Orthogonal Signals

L. W. Nolte and David Jaarsma

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 497-505 (1967); (9 pages) | Cited 3 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
Receiver operating characteristics (ROC's) for the classic problem of detecting the presence or absence of one of M orthogonal signals is presented. Previous results were valid for low detectability, for which the ROC is approximately normal (i.e., appears as a straight line with unit slope on normal normal probability paper) and the detectability depends on the logarithm of the number of possible signals M. For high detectability, however, the ROC departs from normality. In addition, the rate at which detectability decreases as M increases is more rapid than that predicted by the classical approximation.

Pitch of Noise Bands

Arnold M. Small, Jr. and Raymond G. Daniloff

J. Acoust. Soc. Am. Volume 41, Issue 2, pp. 506-512 (1967); (7 pages) | Cited 4 times

Online Publication Date: 21 Jul 2005

Full Text: | Download PDF

Show Abstract
Ten subjects were asked to produce octave judgments, i.e., one octave above and one octave below a standard stimulus, with bands of low‐pass and high‐pass noise as well as sinusoids. For example, given a specific low‐pass noise band as a standard, subjects adjusted the cutoff frequency of a second low‐pass noise band so that its pitch was 1 oct above that of the standard. Results indicate that bands of noise have a pitch and that the pitch is correlated with cutoff frequency. For low‐pass noise, there seemed to be a relatively linear relation between pitch and cutoff frequency from 80‐ to 10 000‐Hz cutoff, whereas the linear relation for high‐pass noise holds only for a restricted frequency range, 600–10 000 Hz. The pitch of both types of noise stimuli degenerates above 10 kHz, possibly because of limited earphone response and a rising threshold of hearing. More difficult to explain is the static and vague pitch of high‐pass noise at low cutoff frequencies. A discussion of several mechanisms is included.
Page 1 of 2 Pages Next Page | Jump to Page
Close

Home Publications Meetings Contact ASA Site Map Back to Top

Copyright © Acoustical Society of America

close