摘要:

The intensity functions which preserve constant loudness under conditions of interaural intensity asymmetry are plotted for pure tones, random noise, and triangular transient stimuli. For all stimuli, the constant loudness function is positively accelerated towards greater decrease per unit increase at the contralateral ear. The rate of acceleration is a function of the binaural summation ratio for each signal. The significance of these data in the design of lateralization studies is discussed.

ISSN:0001-4966    

DOI:10.1121/1.1913231

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Detection and lateralization performance were measured using as a signal the same narrow band of noise that served as the masker. The center frequency of the noise band was either 1000 or 2000 Hz, in different experiments. Both diotic (N0‐S0) and dichotic (N0‐Sπ) data were taken at both frequencies. By varying the signal‐to‐masker ratio and the angle α at which the signal is added to the masker in the N0‐Sπ condition, it is possible to control the magnitudes of the two binaural cues—interaural time difference and interaural level difference. The outcomes at 1000 Hz support our previous findings—subjects differ in their sensitivities to the two cues, and the cues do not cancel perfectly when the task is detection. At 2000 Hz, even relatively large interaural time differences were of little or no benefit either for detection or lateralization, and interaural level difference was the primary binaural cue. At 1000 Hz, sizeable masking‐level differences (MLDs) were observed for all subjects at all values of α. At 2000 Hz, the MLDs were large at α = 0°; however, detectability was essentially the same in the conditions N0‐Sπ, α = 90°, and N0‐S0, α = 90° implying that in both of these conditions performance was based on the increment in level that occurred with signal onset.

ISSN:0001-4966    

DOI:10.1121/1.1913232

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

The invariance that may be found to exist among monaural and antiphasic binaural psychometric functions is briefly reexamined and evidence is presented that is consistent with earlier findings—monaural and antiphasic psychometric functions differ by only a multiplicative factor.

ISSN:0001-4966    

DOI:10.1121/1.1913233

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

An attempt is made to define some limiting conditions for an auditory short‐term memory relatively uncontaminated by verbal encoding or by identification of specific signals. In a one‐interval test, randomly selected, interval‐coded pulse patterns were either repeated exactly after an occurrence of a temporal gap, or were followed by independent randomly selected patterns. Accuracy of identification of repeated patterns is crucially dependent upon the duration of the temporal gap, upon the duration of the auditory pattern, and upon the number of successive representations of the patterns. The optimal temporal gap—about 0.5 sec—is relatively independent of the average interpulse interval, as is the optimal pattern duration—about 64 msec or 8 interpulse intervals.

ISSN:0001-4966    

DOI:10.1121/1.1913234

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

This study quantified the effects of a physiological masker, the heartbeat, on the detectability of a low‐frequency tone (100 Hz, 100‐msec duration). Using aYES‐NOsignal detection paradigm, binaural sensitivity (d′) was examined as a function of the temporal location of the signal onset within the cardiac cycle. The independent variable was the temporal delay in signal onset following the subject's own EKG R wave. Signal delays were selected (0.0 to 0.8 sec in 0.1‐sec steps) and presented to four subjects. Results reveal depressed sensitivity with signal delays of 0.0, 0.3, and 0.7 sec following the EKG R wave. In contrast, maximum sensitivity occurred near 0.5 sec following the R wave. The results were discussed in terms of physiological masking produced by valve closures within the heart.

ISSN:0001-4966    

DOI:10.1121/1.1913235

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Tympanic‐membrane (TM) vibrations were studied in fresh human‐cadaver specimens by means of time‐averaged holography. As with an earlier study in cats [S. M. Khanna and J. Tonndorf, J. Acoust. Soc. Amer.51, 1904 (1972)], the findings supported the curved‐membrane hypothesis of Helmholtz. Despite a careful search for experimental artifacts, no satisfactory explanation was found to account for the fact that the present results are at variance with the stiff‐plate concept of von Békésy. With respect to their quantitative evaluation, the human‐cadaver data were not as clear‐cut as the earlier cat data on account of anatomical differences. A number of points, which on first glance do not seem to agree with Helmholtz's concept are being discussed in the light of present or other recent findings, and explanations are being offered. These topics include: (1) the compliance of the TM; (2) the effects of differential air pressure across the TM upon middle‐ear transmission; (3) the effects of TM perforations; and (4) the fact that Helmholtz's cadaver experiment, which was thought to support his hypothesis, could not be duplicated.

ISSN:0001-4966    

DOI:10.1121/1.1913236

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

The M0‐Sm, M0‐Sπ and M0‐S0 conditions were investigated in a tone‐on‐tone binaural masking paradigm. Both the signal and the masker were gated sinusoids of the same frequency, duration, and rise‐decay time. The data obtained from the two dichotic conditions (M0‐Sπ and M0‐Sm) indicate that, at low frequencies, detection is based entirely on the interaural phase and intensive differences present in the waveforms. At high frequencies, the interaural phase difference was no longer usable as a cue; thus, detection was the same as in the M0‐S0 condition. The interaural intensive difference required for detection was the same at all frequencies. The masking‐level differences (MLDsreM0‐S0) obtained in the M0‐Sm condition were smaller than those obtained in the M0‐Sπ condition and were negative in some situations. The data are in agreement with the predictions of thelateralization modelproposed by Hafter and Carrier [J. Acoust. Soc. Amer.47, 1041–1047 (1970)].

ISSN:0001-4966    

DOI:10.1121/1.1913237

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

This paper describes some further attempts to identify and measure those parameters in the speech signal that reflect the emotional state of a speaker. High‐quality recordings were obtained of professional “method” actors reading the dialogue of a short scenario specifically written to contain various emotional situations. Excerpted portions of the recordings were subjected to both quantitative and qualitative analyses. A comparison was also made of recordings from a real‐life situation, in which the emotions of a speaker were clearly defined, with recordings from an actor who simulated the same situation. Anger, fear, and sorrow situations tended to produce characteristic differences in contour of fundamental frequency, average speech spectrum, temporal characteristics, precision of articulation, and waveform regularity of successive glottal pulses. Attributes for a given emotional situation were not always consistent from one speaker to another.

ISSN:0001-4966    

DOI:10.1121/1.1913238

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

The ultrasonic absorption of aqueous solutions of salmon sperm deoxyribose nucleic acid (DNA), molecular weight of the order of 106, was determined as a function ofpH in the neutral and acidic regions over the frequency range 5–50 MHz at 25°C. The viscous relaxation frequencies appear to be well below 1 MHz. At neutralpH values, viscosity and molecular conformation appear to contribute little in determining the ultrasonic absorption spectrum. The DNA solution absorption spectrum appears to be similar to that of globular protein aqueous solutions implying that the mechanisms may be the same. The ultrasonic absorption acid titration curves for DNA exhibit maxima aroundpH 2.6 and 12 [J. Chim. Phys.66, 81 (1969)] which can be attributed to either or both hydrogen bond transfer and proton transfer as the double helix DNA molecule denatures.

ISSN:0001-4966    

DOI:10.1121/1.1913239

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

A relatively inexpensive method is described for coupling a very good electrostatic earphone to the hollow ear bar of a sterotaxic device. The electroacoustical coupling system is intended for use with mammals in acute physiological work. The amplitude and phase responses of the system, its harmonic distortion, and its response to transient stimuli are presented.

ISSN:0001-4966    

DOI:10.1121/1.1913240

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP