摘要:

In the electromagnetic driver the force per unit current has been shown to be a function of the inductance and the negative stiffness resulting from the presence of the steady magntic field. In this paper it is proven that the force per unit voltage in the electrostatic device is a similar function of the capacity and the negative stiffness due to the steady electrostatic field.A new concept called Motional Admittance is introduced for the electrostatic loud speaker and this is shown to be similar in its mathematical form to the Motional Impedance of the electromagnetic driver.A calculation of the ultimate theoretical efficiency that may be obtained with an electrostatic speaker having a pure resistance radiator and covering a given frequency range is given. It appears that efficiencies between 5 and 10% may some day be obtainable with good fidelity of reproduction.

ISSN:0001-4966    

DOI:10.1121/1.1915248

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP

摘要:

A brief review of the properties of horns as described in recent years by various writers is given. Reasons for the small throat, the large mouth, and the exponential shape are discussed.

ISSN:0001-4966    

DOI:10.1121/1.1915249

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915250

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915251

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915252

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915253

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP

摘要:

Measurements of phase difference and amplitude ratio of the sound entering the ears of a man‐shaped wax dummy were taken with the source at varying azimuths around the head; at 256, 1024, and 1944 cycles per second; and at distances of 20, 50, 100, and 400 cm. from the head. The measurements at the two lower frequencies agree with the values published by Hartley and Fry computed on the assumption that the head is a rigid sphere in free space, except that the observed values of amplitude ratio are about 13 percent less than the computed values on account of the interference of the neck. The observed values at 1944 cycles are quite different from the computed values.

ISSN:0001-4966    

DOI:10.1121/1.1915254

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP

摘要:

Pure tones of frequency 256 cycles per second were presented binaurally to eight different observers, the phase difference and amplitude ratio of the acoustical pressures at the two ears being known and adjustable. The observers were asked to state the direction and distance of the apparent source of sound. Only three of the eight observers were influenced their judgment of direction by the phase difference and even they were rather inaccurate. All were influenced more or less in judging direction, by the amplitude ratio. None was able to tell the distance of the source by the amplitude ratio.

ISSN:0001-4966    

DOI:10.1121/1.1915255

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP

摘要:

Audition resulting from vibration of the skull is investigated in various respects using audiometers with bone conduction receivers and other equipment. Applying the driving element at any point sets the entire skull into vibration, and the stimulus in one ear resulting from driving the skull on that mastoid is found to exceed the stimulus in the other ear by only 3.4±2.2 decibels. The statistical accuracy of bone conduction observations is found and compared with published air conduction results. The sensitivity on the mastoid exceeds that on the forehead by 5 db on the average. Tests of instruments for measuring air conduction and bone conduction sensitivity to determine the amount of desired over undesired type of stimulation are described and the results given. The effect of a telephone receiver in producing hearing in the opposite ear is observed with two available cases of assured total deafness on one side and the data given. Beats involving bone conduction are observed. The fact that bone conduction sensations often seem in one ear is compared with similar results for air conduction stimuli under certain conditions and a general statement of all results is made. The problems of apparent hyper‐sensitivity resulting from abnormality and occlusion are discussed in the light of the foregoing results.

ISSN:0001-4966    

DOI:10.1121/1.1915256

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1915257

出版商:Acoustical Society of America    

年代:1930

数据来源: AIP