摘要:

This paper describes several exploratory experiments on a subjective tone that Zwicker discovered and referred to as the “negative afterimage.” Zwicker described the tone as audible upon cessation of a band‐rejected noise or band‐rejected pulse train stimulus, and as having a pitch corresponding to a frequency within the rejected band. We worked exclusively with noise stimuli. Our principal finding is that the minimum adequate stimulus appears to be a spectral edge rather than a rejected band, and that a low‐pass edge is more effective than a high‐pass edge. Other findings are as follows. Most people hear the tone, but susceptibility varies widely and the effect is labile. With favorable stimulus parameters, precision of matching to its pitch is on the order of 5% to 10% of the mean. The principal determinant of pitch is the location of the edge of the low‐pass component of the stimulus; the pitch corresponds to a frequency about23 octabove that edge. Energy in the high‐pass component of the inducing stimulus enhances perception of the tone but has little effect on its pitch.

ISSN:0001-4966    

DOI:10.1121/1.1913052

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Rabiner, Laurence, and Durlach [J. Acoust. Soc. Amer.40, 62–70 (1966)] reported that the masking‐level difference (MLD) for uncorrelated noise with signals in‐phase and reversed in‐phase at the ears was independent of signal frequency for frequencies between 150 and 1000 Hz. Since all other “MLD conditions” show marked signal‐frequency effects, and since the E‐C model predicts that such effects will also occur with uncorrelated noise, the present study reinvestigates the effect of signal frequency on the MLD for uncorrelated noise. The results indicate that the MLD for NUS0 decreases with increasing signal frequency.

ISSN:0001-4966    

DOI:10.1121/1.1913053

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Frequency discrimination for a tone of short duration may be strongly affected by the temporal proximity of another tone. One of the effects is unlike either masking or memory interference and may be related to the time required by the auditory system for frequency organization.

ISSN:0001-4966    

DOI:10.1121/1.1913054

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Magnitude estimates were obtained for the loudness of 77 pure tones varying in frequency (11 values) and intensity (seven values) when (1) all 77 tones were presented intermixed within a session, and (2) all tones of one frequency were presented before presenting tones of another frequency. A power function described the growth of loudness for each frequency for both conditions 1 and 2, and the exponent of the power function varied with frequency. Equal loudness contours were derived from the power functions of Condition 1 and were compared to those obtained from other experiments using different procedures.

ISSN:0001-4966    

DOI:10.1121/1.1913055

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Two‐channel auditory signal detection was investigated with narrow‐band noise signals masked by independent, binaurally uncorrelated noise. The two‐channel tasks included conditions where the signals in each channel were correlated, uncorrelated, or opposite in phase. No significant differences were observed between the single‐channel conditions and the two‐channel correlated signal condition, but performance in the uncorrelated and 180° phase conditions was significantly poorer. A comprehensive analysis of cross‐channel interaction indicated a cross‐channel inhibitory or masking effect, which may be counteracted by the presence of lateralization cues. Constraints on signal detectability due to a limited processing capacity appeared to be negligible.

ISSN:0001-4966    

DOI:10.1121/1.1913056

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Detection of a masked signal (500 Hz) at one ear was measured while a sinusoid of the same frequency and a noise were presented to the contralateral ear. Both the signal and the contralateral sinusoids were pulsed, and they were either in phase or inverted. The noise at the signal ear was presented continuously at a spectrum level of 40 dB. In Expt. 1, the same continuous noise was presented to the contralateral ear at a spectrum level of 40 dB and in phase with the noise in the signal ear. The contralateral sinusoid‐to‐noise ratio was varied by changing the level of the sinusoid. In Expt. 2, the contralateral sinusoid‐to‐noise ratio was held constant while the levels of both the contralateral sinusoid and the contralateral noise were varied. When the contralateral sinusoid and noise are intense, a 50‐dB increase in the contralateral sinusoid‐to‐noise ratio causes a 25‐ to 35‐dB change in the signal‐to‐noise ratio required for detection. The results show that contralateral stimulation can either enhance or degrade detection of a monaural signal. The results are compared to data from investigations of masking‐level difference, central masking, and monarual detection with contralateral cue.

ISSN:0001-4966    

DOI:10.1121/1.1913057

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

This paper is a presentation of the first application of the techniques of vibration analysis by hologram interferometry to the study of stringed instrument resonances. The instrument studied was the treble viol, which was a convenient size for a hologram system and allowed approximate simulation of the actual instrument by the clamped top plate. After study of an instrument of classical proportions by hologram interferometry, a new instrument was designed that was longer, wider, and flatter. Holographic study of the top plate of this new instrument verified that it should function well on a finished instrument since its resonance frequencies suited the instrument range. The rest of the instrument was built and tested holographically after assembly to confirm the previous simulation. The instrument was completed and played with very good results, i.e., more volume, easier playing, and more agreeable tone than the classically designed treble viol. The primary experimental difficulty encountered was the swelling of the wooden plates with humidity which adversely affected real‐time interferometry, and the steps taken to overcome this were only partially successful.

ISSN:0001-4966    

DOI:10.1121/1.1913058

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

Sensations of tone, including violin tone, come partly from evoked matrices generated within the brain. Cited evidence from electrodes permanently implanted in the brains of conditioned cats shows that an incoming signal evokes generation of temporally patterned recurrences. The cat acts appropriately for the signal when coincidence exists between the input and the internally generated pattern. An adequately functioning nervous system experiences tone from input of regularly repeating waves, such as are compatible with neural temporal recurrence, but human patients with some neural handicaps, including vertebral artery insufficiency, commonly experience noise instead of tone from smooth sine wave input, presumably because of inadequate internal generation or coincidence detection. The normal human nervous system, with many neurons responding only to change, is not a steady‐state apparatus, yet it uses temporal recurrence with an appetite for regularity. Human preference for regularity and change can be observed when a master plays a violin which is thus physiologically controlled.

ISSN:0001-4966    

DOI:10.1121/1.1913059

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

The directional characteristics of sound radiation were investigated for violins, violas, cellos, and contrabasses. Each instrument group has a nondirectional characteristic in its lowest frequency range except the contrabass. At higher frequencies, there are regions of preferred radiation, which change their direction and anglewidth with frequency. These results suggest that different seating arrangements for the strings would be optimum for different concert halls and different styles of musical compositions. The European seating system is optimum for the radiation of the cellos; it has the advantage that the sound character of the first and second violins may be distinguished by the audience, but the sound of the second violins has no brilliance. The American system makes the second violins sound as good as the first violins, but it is difficult to distinguish both groups in contrapuntal passages of classical symphonies. The sound of the cellos is poor and without clarity. The validity of these findings is confirmed by measurements in concert halls, and they have been used for guidance in changing the seating arrangement of an orchestra to improve the instrumental balance with successful results.

ISSN:0001-4966    

DOI:10.1121/1.1913060

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP

摘要:

In the tuning device being described a reference oscillator generates 84 crystal‐controlled frequencies, which follow a stretched scale whose deviations are programmed in an interchangeable diode matrix. Three different diode matrices have been realized, intended for tuning small, medium‐size, and grand piano's, respectively. A bandpass filter is used, the transmission range of which automatically follows the reference frequency. An electromagnetic device is used as a sound transducer. In consequence of this, tuning of all strings on their fundamentals becomes fully feasible. With one medium‐size piano, the achieved accuracy was measured. The accuracy of the tuning with respect to the reference frequency was<10−4in all cases. The total accuracy (including the inaccuracy of the reference oscillator) varies from 10−4for the lowest note to 5×10−4for the highest note.

ISSN:0001-4966    

DOI:10.1121/1.1913061

出版商:Acoustical Society of America    

年代:1972

数据来源: AIP