Attenuation Rate in Sweep Frequency Békésy Audiometry

1973 ◽  
Vol 7 (2) ◽  
pp. 49-51
Author(s):  
K. Chiveralls ◽  
S. D. Shaw
Keyword(s):  
Sweep Frequency ◽  
Attenuation Rate ◽  
Békésy Audiometry

Record Wear Studies by Scanning Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 364-365
Author(s):  
M.D. Coutts ◽  
E.R. Levin ◽  
J.G. Woodward
Keyword(s):  
Electron Microscopy ◽  
Constant Velocity ◽  
Peak Velocity ◽  
Great Depth ◽  
Depth Of Focus ◽  
Sweep Frequency ◽  
Transmission Electron ◽  
Test Record ◽  
Lateral Mode ◽  
Scanning Electron

While record grooves have been studied by transmission electron microscopy with replica techniques, and by optical microscopy, the former are cumbersome and restricted and the latter limited by lack of depth of focus and resolution at higher magnification. With its great depth of focus and ease in specimen manipulation, the scanning electron microscope is admirably suited for record wear studies.A special RCA sweep frequency test record was used with both lateral and vertical modulation bands. The signal is a repetitive, constant-velocity sweep from 2 to 20 kHz having a duration and repetitive rate of approximately 0.1 sec. and a peak velocity of 5.5 cm/s.A series of different pickups and numbers of plays were used on vinyl records. One centimeter discs were then cut out, mounted and coated with 200 Å of gold to prevent charging during examination. Wear studies were made by taking micrographs of record grooves having 1, 10 and 50 plays with each stylus and comparing with typical “no-play” grooves. Fig. 1 shows unplayed grooves in a vinyl pressing with sweep-frequency modulation in the lateral mode.

Race Difference in Auditory Sensitivity

1964 ◽  
Vol 7 (4) ◽  
pp. 389-393 ◽  
Author(s):  
David C. Shepherd ◽  
Robert Goldstein ◽  
Benjamin Rosenblüt
Keyword(s):  
White Women ◽  
White Men ◽  
Sensitivity Study ◽  
Auditory Sensitivity ◽  
Race Difference ◽  
Men And Women ◽  
Auditory Thresholds ◽  
Békésy Audiometry ◽  
Method Of Adjustment ◽  
Better Than

Two separate studies investigated race and sex differences in normal auditory sensitivity. Study I measured thresholds at 500, 1000, and 2000 cps of 23 white men, 26 white women, 21 negro men, and 24 negro women using the method of limits. In Study II thresholds of 10 white men, 10 white women, 10 negro men, and 10 negro women were measured at 1000 cps using four different stimulus conditions and the method of adjustment by means of Bekesy audiometry. Results indicated that the white men and women in Study I heard significantly better than their negro counterparts at 1000 and 2000 cps. There were no significant differences between the average thresholds measured at 1000 cps of the white and negro men in Study II. White women produced better auditory thresholds with three stimulus conditions and significantly more sensitive thresholds with the slow pulsed stimulus than did the negro women in Study II.

The Effects of Sophistication on Type V Bekesy Patterns in Simulated Hearing Loss

1975 ◽  
Vol 40 (4) ◽  
pp. 508-513 ◽  
Author(s):  
Frederick N. Martin ◽  
Deborah A. Monro
Keyword(s):  
Hearing Loss ◽  
Normal Hearing ◽  
General Decrease ◽  
Continuous Tone ◽  
Type V ◽  
Békésy Audiometry ◽  
Off Time

Forty-five normal-hearing subjects were divided into three groups according to sophistication regarding Bekesy audiometry in simulated hearing loss. Both standard pulsed (200 msec on/200 msec off) and lengthened off-time (200 msec on/800 msec off) were compared with a continuous tone tracing at 1000 Hz. Data revealed a general decrease in the number of Type V patterns observed as sophistication increased.

scholarly journals Békésy Audiometry in Animals

1965 ◽  
Vol 38 (5) ◽  
pp. 917-917
Author(s):  
K. Lowy ◽  
J. Webster ◽  
R. Spragg
Keyword(s):  
Békésy Audiometry

Bekesy Audiometry

1962 ◽  
Vol 1 (2) ◽  
pp. 160-164 ◽  
Author(s):  
J. Jerger
Keyword(s):  
Békésy Audiometry

scholarly journals Radiometric Performance Evaluation of FY-4A/AGRI Based on Aqua/MODIS

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1859
Author(s):  
Bo Zhong ◽  
Yingbo Ma ◽  
Aixia Yang ◽  
Junjun Wu
Keyword(s):  
Near Infrared ◽  
Spectral Response ◽  
Convective Cloud ◽  
Radiation Level ◽  
High Attenuation ◽  
Total Attenuation ◽  
Attenuation Rate ◽  
Calibration Facility ◽  
Deep Convective Cloud ◽  
Directional Reflectance

Fengyun-4A (FY-4A) is the first satellite of the Chinese second-generation geostationary orbit meteorological satellites (FY-4). The Advanced Geostationary Radiation Imager (AGRI), onboard FY-4A does not load with high-precision calibration facility in visible and near infrared (VNIR) channel. As a consequence, it is necessary to comprehensively evaluate its radiometric performance and quantitatively describe the attenuation while using its VNIR data. In this paper, the radiometric performance at VNIR channels of FY-4A/AGRI is evaluated based on Aqua/MODIS data using the deep convective cloud (DCC) target. In order to reduce the influence of view angle and spectral response difference, the bi-directional reflectance distribution function (BRDF) correction and spectral matching have been performed. The evaluation result shows the radiometric performance of FY-4A/AGRI: (1) is less stable and with obvious fluctuations; (2) has a lower radiation level because of 24.99% lower compared with Aqua/MODIS; 3) has a high attenuation with 9.11% total attenuation over 2 years and 4.0% average annual attenuation rate. After the evaluation, relative radiometric normalization between AGRI and MODIS in VNIR channel is performed and the procedure is proved effective. This paper proposed a more reliable reference for the quantitative applications of FY-4A data.

Investigation on a two-stage platform of large stroke for broadband vertical vibration isolation

2018 ◽  
Vol 25 (6) ◽  
pp. 1233-1245 ◽  
Author(s):  
Xiling Xie ◽  
Mingke Ren ◽  
Hongbo Zheng ◽  
Zhiyi Zhang
Keyword(s):  
Vibration Isolation ◽  
Vertical Vibration ◽  
Optical Switches ◽  
Static Properties ◽  
Two Stage ◽  
Maximum Displacement ◽  
Primary Stage ◽  
Low Frequencies ◽  
Attenuation Rate ◽  
Secondary Stage

For the purpose of preventing vibration-sensitive optical switches from malfunction caused by broadband vertical vibration, a novel two-stage vibration isolation platform is proposed. The primary stage is a bellows-type isolator of large stroke and low isolation frequency, and the secondary stage is a small-stroke hybrid isolator composed of bellows and voice-coil actuators. In the primary stage, two pre-compressed horizontal bellows and one vertical bellows are used to counter the weight of the switch and to reduce the total height of the isolator. The static properties of the primary stage are analyzed, and the vibration isolation of the platform is investigated. Numerical results indicate that the two-stage platform is effective in isolating vertical vibration. Experiments are also conducted to verify the performance of the platform. It is exhibited that the transmissibility is less than 0 dB over 2 Hz, and the attenuation rate reaches −35 dB/dec at high frequencies. The frequency range of test is 2–200 Hz, and the maximum displacement is 10 mm at 2 Hz. In the secondary stage, the actuators can substantially suppress the resonance peak, and promote isolation performance at low frequencies.

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