摘要:

Double‐dumbbell transducer elements of two commercial nickel‐copper‐cobalt‐ferrous ferrites (Ferroxcube 7A1 and 7A2) with acoustic “pressure‐release” material at each end were placed between the jaws of a hydraulic pressure testing machine. The effective electromechanical coupling coefficient for the sample was measured for various magnetizing currents and static loads. As the load was increased to 5600 lb, corresponding to 4600 psi in the narrow “limbs” of the element, the effective coupling coefficient at optimum bias decreased from 0.21 to 0.05, and the clamped inductance (which is proportional to the incremental permeability) decreased by 40 per cent.

ISSN:0001-4966    

DOI:10.1121/1.1908917

出版商:Acoustical Society of America    

年代:1961

数据来源: AIP

摘要:

Some obscure but important philosophical difficulties with the standard method of measuring transmission loss by the reverberant room method have led to reexamination of the basic concepts. An equation is derived relating transmission loss to the “total loss area”H2of the receiving room.H2is found to be measurable within a negligibly small uncertainty, using familiar sound‐decay techniques, providing thatT2/T1, the ratio of “natural” reverberation times of the receiving and source rooms is properly adjusted. It is shown that the equations commonly used in the existing standard method require knowledge ofA2, the total absorption of the receiving room, implicitly excluding transmission through the panel.A2is not generally measurable without prior knowledge of the transmission loss of the test panel. These and other considerations result in the proposal of a new procedure.

ISSN:0001-4966    

DOI:10.1121/1.1908919

出版商:Acoustical Society of America    

年代:1961

数据来源: AIP

摘要:

Binaural masked thresholds from 50 cps to 4800 cps were measured using low‐frequency (10, 15, 25, 30, and 50 cps), high‐intensity (100, 115, and 130 db SPL) pure tones. The results obtained for 5 listeners demonstrate a broad masking spread with masking peaks for 130‐db SPL pure tones.

ISSN:0001-4966    

DOI:10.1121/1.1908921

出版商:Acoustical Society of America    

年代:1961

数据来源: AIP

摘要:

The results of Harris and collaborators on the discrimination of combinations of auditory intensity and frequency differences were examined with reference to four models of auditory discrimination. Of the four, the most successful prediction of the effect of combinations of intensity and frequency differences assumes a recognizable threshold for each of the stimulus variables.

ISSN:0001-4966    

DOI:10.1121/1.1908923

出版商:Acoustical Society of America    

年代:1961

数据来源: AIP

摘要:

Forced choice and yes‐no auditory detection data were examined for single‐trial dependencies of the correctness of the response. In both procedures a correct response is more likely when the previous response was correct than when it was wrong. The effect of various characteristics of the signal were studied in the forced‐choice procedure: the dependence is more pronounced for higher‐intensity signals and for signals of a pure tone rather than for an increment in background noise. An attempt is made to relate these findings to a criterion‐correction explanation of the sequential dependence.

ISSN:0001-4966    

DOI:10.1121/1.1908925

出版商:Acoustical Society of America    

年代:1961

数据来源: AIP

摘要:

A major obstacle in attempting quantitative investigations of the influence of microstreaming on solid‐liquid interface reactions has been the inability to prevent gaseous cavitation (which destroys the orderly streaming action) from occurring in the liquid medium when the latter is subjected to a high‐amplitude sound field. The present article describes a modification of an earlier experimental arrangement, used to study microstreaming effects on a specific interphase chemical reaction (i.e., development of a photographic emulsion), which incorporates a means for suppressing undesired cavitation. Preliminary results obtained using this apparatus are presented. These results permit a more precise correlation between observed effects and properties of the streaming field than has hitherto been possible. Preliminary data indicating the extent to which microstreaming affects the local development rate are also presented.

ISSN:0001-4966    

DOI:10.1121/1.1908927

出版商:Acoustical Society of America    

年代:1961

数据来源: AIP

摘要:

The harmonic content of 25‐kc sound transmitted through water was measured as a function of ambient pressure (0–12 atm) and an inverse relationship was found to hold; the nonlinearity disappeared completely at the higher pressures. It is suggested that gaseous cavitation, a pressure‐dependent phenomenon, may be involved as a mechanism in the sound transmission.

ISSN:0001-4966    

DOI:10.1121/1.1908929

出版商:Acoustical Society of America    

年代:1961

数据来源: AIP

摘要:

This investigation was conducted to determine the feasibility of a compact, lightweight, multi‐element broadband transducer. Three bender‐type elements with proportionately spaced resonant frequencies were assembled in a cluster. The assembly proved capable of radiating from 1.75–2.70 kc with not more than ±1.5 db power variation, if the elements were properly spaced. This investigation demonstrated that lowQdevices can be constructed from a combination of stagger‐tuned highQelements providing that proper orientation and spacing are observed.

ISSN:0001-4966    

DOI:10.1121/1.1908931

出版商:Acoustical Society of America    

年代:1961

数据来源: AIP

ISSN:0001-4966    

DOI:10.1121/1.1908933

出版商:Acoustical Society of America    

年代:1961

数据来源: AIP