ISSN:0001-4966    

DOI:10.1121/1.1906690

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1906691

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP

摘要:

Binaural experiments are described which indicate that the ability of the brain to localize a desired sound and to suppress undesired sounds coming from other directions can be traced in part to the different times of arrival of a sound at the two ears. It is suggested that the brain inserts a time delay in one of the two nerve paths associated with the ears so as to be able to compare, and thus concentrate on, those sounds arriving at the ears with this particular time of arrival distance.The ability to perceive weak sounds binaurally in the presence of noise is shown to be a simple function of the direction of the desired sound and noise. An explanation is given for the effect reported by Koenig that front and rear confusion is avoided by head movements.

ISSN:0001-4966    

DOI:10.1121/1.1906692

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1906693

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP

摘要:

This is an interim report on studies of the specification of speech sounds from acoustical measurements. Methods based upon analysis, synthesis, and vocal tract models are described. Included are the results of preliminary measurements on the vowel sounds of 25 speakers. Some of the problems in specifying the vowel sounds as indicated by these results are discussed.

ISSN:0001-4966    

DOI:10.1121/1.1906694

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP

摘要:

This paper describes two ways of reducing the normally very complicated speech wave to simple geometrical form without destroying intelligibility, reports the results of articulation tests of the simplified speech, and gives two illustrations of things that can be done more simply with the simplified than with the normal wave. Both methods of simplification involve dichotomization of the amplitude scale and then quantization of the time scale. The first step is achieved by subjecting the speech wave to infinite peak clipping, the second by generating a rectangular wave whose switchings from one amplitude level to the other are related to the switchings of the clipped speech wave by one or the other of two rules. One of the rules yields marginal intelligibility with quanta 0.2 millisecond in length; the other requires slightly shorter quanta. The relative merits of the two methods are accounted for by an elementary application of information theory. Autocorrelation functions, which are especially easy to compute for the simplified waves, are shown.

ISSN:0001-4966    

DOI:10.1121/1.1906695

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP

摘要:

Delayed speech feedback may act as a governor of the average speed of speech operating on the phoneme unit. Certain aurally monitored manual tasks resemble the speech mechanism. The trigger‐like nature of aurally monitored voice on the more rapid articulation element is described. A speech mechanism model is portrayed which satisfies phenomena of natural speech, artificial stutter, and motor aphasias.

ISSN:0001-4966    

DOI:10.1121/1.1906696

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP

摘要:

The excitation pattern of a tone is markedly altered by a masking stimulus. It should be expected that the pitch of the masked tone, as well as its threshold and its loudness, would be affected. In the present investigation the effect of a narrow band of noise (90 c.p.s. wide, centered at 410 c.p.s.) upon the pitch of pure tones of low frequency was measured in a series of experiments. Subjects matched the pitch of a tone heard in the presence of a band of noise to the pitch of a tone heard alone. These two tones, one partially masked and the other not, were presented to the subject in repeated succession. The listener first matched these tones for loudness. He then adjusted the frequency of the unmasked tone until it was the same in pitch as the masked tone. The pitch change was investigated at a number of frequencies and of loudness levels.Systematic changes in pitch were observed. The presence of the noise raises the pitch of a partially masked tone whose frequency is immediately above those of the band of noise. This change in pitch occurs even though the intensity of the masked tone is greater than that of the unmasked tone. In contrast, the presence of the masking noise lowers the pitch of a tone whose frequency is just lower than those of the band of noise, but this change is largely accounted for in terms of the intensity difference required for an equal loudness match. An attempt is made to account for the changes in pitch in terms of a place theory.

ISSN:0001-4966    

DOI:10.1121/1.1906697

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP

摘要:

Simple procedures are given for the subjective measurement of earphone response by two methods. The first method, which is rather widely recognized, requires the subject to match the loudness of an earphone tone to the loudness of a free‐field reference tone of the same frequency. Interpretation of the data from this method is direct, but the facilities, technique and time required are considerable. A second method, less widely used, involves the loudness balancing of an earphone tone of variable frequency to that of an earphone reference tone of fixed frequency and level. This method is much simpler, and can be used to measure earphone response under circumstances where the first method is virtually impossible. However, the interpretation of the data is less direct. This paper is an analysis of the two methods which attempts to develop a correspondence between the data obtained by the two methods.

ISSN:0001-4966    

DOI:10.1121/1.1906698

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP

摘要:

A general description is given of the procedure developed at the National Bureau of Standards for calibrating audiometers. The sources of calibration standards are presented, and there is a discussion of the physics underlying the present technique. Limitations on the validity of the threshold data are pointed out. A method for determining the calibration of audiometer earphones is described. Data on earphone response can be used to gain some insight into the malfunctioning of an audiometer, and the way in which this can be done is indicated.

ISSN:0001-4966    

DOI:10.1121/1.1906699

出版商:Acoustical Society of America    

年代:1950

数据来源: AIP