摘要:

The decibel changes required to halve and to double the apparent loudness of a white noise were determined at nine sound pressure levels by 36 subjects. The subjects adjusted the level of the noise by means of an improved control—a “sone potentiometer” whose angular turn is roughly proportional to the loudness produced. An attempt was also made to measure and control some of the biasing factors that affect loudness estimations. Results: the median decibel changes required to produce a 2:1 loudness ratio ranged from 6 to 10 db, approximately.

ISSN:0001-4966    

DOI:10.1121/1.1907524

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP

摘要:

As a sequel to experiments on the transmission of the vocal cavities, calculations on a model of the vocal tract for the vowel /i/ (meat) are performed to determine the magnitude of the impedances along the vocal tract and the relative contribution of radiation, friction, and coupled vibrations of the cavity walls to the total damping. Calculations also are made to estimate the impedances of the different parts of the larynx. From these calculations the effects of the coupling of the vocal cavities upon the larynx can be understood. Finally an old singing‐pedagogical problem concerning the resonances in the head is discussed.

ISSN:0001-4966    

DOI:10.1121/1.1907525

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP

摘要:

Sixteen English consonants were spoken over voice communication systems with frequency distortion and with random masking noise. The listeners were forced to guess at every sound and a count was made of all the different errors that resulted when one sound was confused with another. With noise or low‐pass filtering the confusions fall into consistent patterns, but with high‐pass filtering the errors are scattered quite randomly. An articulatory analysis of these 16 consonants provides a system of five articulatory features or “dimensions” that serve to characterize and distinguish the different phonemes: voicing, nasality, affrication, duration, and place of articulation. The data indicate that voicing and nasality are little affected and that place is severely affected by low‐pass and noisy systems. The indications are that the perception of any one of these five features is relatively independent of the perception of the others, so that it is as if five separate, simple channels were involved rather than a single complex channel.

ISSN:0001-4966    

DOI:10.1121/1.1907526

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP

摘要:

A scale of noise intermittancy may be represented at one extreme by a continuous noninterrupted noise and, on the other extreme, by an interrupted noise with silent intervals between successive noise bursts. The differential characteristic for various conditions along this scale is the noise level in the interval between successive noise bursts (the inter‐burst level). The effects of a wide range of periodically intermittant noise conditions upon the masked threshold of a tone and the intelligibility of speech were examined. The principal result of these tests is that the masked threshold associated with an intermittant noise can be closely described by two functions: (1) the masking produced by an interrupted noise with silent intervals between successive noise bursts, and, (2) the masking produced by a continuous uninterrupted noise at the inter‐burst level.

ISSN:0001-4966    

DOI:10.1121/1.1907527

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP

摘要:

Fatigue and other effects of 3 minutes of strong (105 db) acoustic stimulation were studied. Four combinations of fatiguing sound (white noise or 2‐kc tone) and test frequency (3 or 4 kc) were each used twice for each of 24 Ss. Mean threshold recovery, functions closely resembled many of the individual functions reported by Hirsh and Ward and confirmed the phenomenon they called “bounce” however, many individual functions, like Hood's, were monotonic. Largest inter‐subject and smallest intra‐subject variability were associated with the noise/4000 combination. Ss differed considerably with respect to general fatiguability and recovery rate, and they tended to remain in the same rank order throughout the post‐stimulatory period. There was a positive but low relationship between the fatigue a S displayed under one condition and what he displayed after the same recovery time under another condition; the relationship was generally highest after the first 3 minutes following stimulation. Many individual recovery charts displayed roughness indicative of a recurring disturbance of considerably shorter duration than the bounce effect. There was no obvious relationship between threshold shift and display of either roughness or bounce; nor could these latter two phenomena be entirely accounted for by tinnitus.

ISSN:0001-4966    

DOI:10.1121/1.1907528

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP

摘要:

Two similar cases of tonal monaural diplacusis are described. When low‐intensity sinusoids within a certain range are presented, several distinct tones are heard in addition to the tone presented. The effects are focussed at 3610 cps for one subject and at 3155 cps for the other. Pitch‐matching and probe‐tone techniques show that the additional tones correspond to combination tones expected in a normal ear stimulated by two tones, one of which is fixed at one of the above frequencies. Hence some basic instability of the auditory mechanism at these frequencies is indicated for these observers. It is suggested that the defect lies in the “peaking” process of the cochlea, so that an adequate explanation of the phenomena may be of some importance to auditory theory.

ISSN:0001-4966    

DOI:10.1121/1.1907529

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP

摘要:

Sound pressures measured with a probe‐tube microphone in front of the tympanic membrane of the guinea pig have been compared at 100‐cps intervals in the frequency range 50 to 8000 cps to the sound pressures similarity measured in a speculum coupling an acoustic source to the ear canal. Rather different functions were obtained for each of five conditions: (1) normal, (2) hair‐line slit in the tympanic membrane, (3) rupture of tympanic membrane, (4) fluid behind tympanic membrane, and (5) bulla open. The variability in each of the categories is presented. Variability was greatest in the normal ears and least in the bulla open ears.

ISSN:0001-4966    

DOI:10.1121/1.1907530

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP

摘要:

The standard magnitude ratio of 100.1is accepted as a useful device for the specification of relative magnitudes. The significance of such a standard‐magnitude ratio when considered as the basis of a unit is discussed. The namedecilitis suggested.

ISSN:0001-4966    

DOI:10.1121/1.1907863

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP

摘要:

Measurements during two heavy rainstorms through an off‐shore calibrated hydrophone system showed an increase of up to 25 db in the 20 to 20 000 cps band pressure level as compared to the ambient level before and after. During the period of heaviest rainfall the pressure spectrum level was approximately constant at−23db//1 dyne/cm2from below 1 kc to above 10 kc, and apparently extends to beyond 40 kc. The pressure spectrum level of the ambient noise can be calculated from the wind force and from a reasonable estimate of the intensity of rainfall.

ISSN:0001-4966    

DOI:10.1121/1.1907897

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1907906

出版商:Acoustical Society of America    

年代:1955

数据来源: AIP