scholarly journals Localization of sound in the vertical plane with and without high-frequency spectral cues

1992 ◽  
Vol 51 (2) ◽  
pp. 182-186 ◽  
Author(s):  
Robert A. Butler ◽  
Richard A. Humanski
Keyword(s):  
High Frequency ◽  
Vertical Plane ◽  
Spectral Cues

Remote monitoring of the steam‐flood enhanced oil recovery process

Geophysics ◽  
1987 ◽  
Vol 52 (11) ◽  
pp. 1457-1465 ◽  
Author(s):  
E. F. Laine
Keyword(s):  
Oil Recovery ◽  
Heavy Oil ◽  
High Frequency ◽  
Oil Sands ◽  
Seismic Velocity ◽  
Color Image ◽  
Vertical Plane ◽  
Recovery Process ◽  
Steam Flood ◽  
Borehole Seismic

Cross‐borehole seismic velocity and high‐frequency electromagnetic (EM) attenuation data were obtained to construct tomographic images of heavy oil sands in a steam‐flood environment. First‐arrival seismic data were used to construct a tomographic color image of a 10 m by 8 m vertical plane between the two boreholes. Two high‐frequency (17 and 15 MHz) EM transmission tomographs were constructed of a 20 m by 8 m vertical plane. The velocity tomograph clearly shows a shale layer with oil sands above it and below it. The EM tomographs show a more complex geology of oil sands with shale inclusions. The deepest EM tomograph shows the upper part of an active steam zone and suggests steam chanelling just below the shale layer. These results show the detailed structure of the entire plane between boreholes and may provide a better means to understand the process for in situ heavy oil recovery in a steam‐flood environment.

scholarly journals The role of spectral cues in vertical plane elevation perception

2020 ◽  
Vol 41 (1) ◽  
pp. 435-438
Author(s):  
Dingding Yao ◽  
Junfeng Li ◽  
Risheng Xia ◽  
Yonghong Yan
Keyword(s):  
Vertical Plane ◽  
Spectral Cues

Modulation of the human vestibuloocular reflex during saccades: probing by high-frequency oscillation and torque pulses of the head

1996 ◽  
Vol 76 (5) ◽  
pp. 3249-3263 ◽  
Author(s):  
S. Tabak ◽  
J. B. Smeets ◽  
H. Collewijn
Keyword(s):  
High Frequency ◽  
Time Course ◽  
Vertical Plane ◽  
Vertical Component ◽  
Head Movements ◽  
High Frequency Oscillation ◽  
Vestibuloocular Reflex ◽  
Control Mechanisms ◽  
Gaze Shift ◽  
Gaze Saccades

1. We probed the gain and phase of the vestibuloocular reflex (VOR) during the execution of voluntary gaze saccades, with continuous oscillation or acceleration pulses, applied through a torque helmet. 2. Small-amplitude (< 1 degree), high-frequency (10-14 Hz) head oscillations in the horizontal or vertical plane were superimposed on ongoing horizontal gaze saccades (40-100 degrees). Torque pulses to the head (“with” or “against” gaze) were superimposed on 40 degrees horizontal saccades. Eye and head movements were precisely measured with sensor coils in magnetic fields. 3. Techniques were developed to separate the oscillatory (horizontal or vertical) component from the gaze shift and obtain VOR gain and phase with Fourier techniques from the relation between eye-in-head and head oscillations. These involved either subtraction of exactly matching saccades with and without oscillation (drawback: low yield) or time shifting of successive trials to synchronize the oscillations (drawback: slight time blurring of saccades). 4. The results of these matching and synchronization methods were essentially identical and consistent. Presaccadic gain values of the horizontal VOR (typically about unity) were reduced by, on average, approximately 20 and 50% during horizontal saccades of 40 and 100 degrees, respectively. These percentages may be truncated because of methodological limitations, but even after taking these into account (on the basis of simulation experiments with 2 different, theoretical profiles of suppression) our results do not support a complete saccadic VOR suppression for any substantial fraction of saccadic duration. Qualitatively similar changes were found when the vertical VOR was probed during 100 degrees horizontal saccades. 5. Concomitantly with the reductions in gain, VOR phase was advanced by approximately 20 degrees during the saccade. 6. In the wake of gaze saccades, VOR gain was consistently elevated (to approximately 1.0) above the presaccadic level (approximately 0.9). We submit that this mechanism ensures stable fixation of the newly acquired target at a time when the head is still moving substantially. 7. Although the responses to head torque pulses showed idiosyncratic asymmetries, analysis of the differences in eye and head movements for pulses with and against consistently showed a sharp fall of VOR gain at saccadic onset, following an approximately exponential course with a time constant of approximately 50 ms. This decay may be assumed to reflect VOR gain for a period of approximately 50 ms, after which secondary gaze control mechanisms become dominant. 8. The time course of the gain decay and phase shift of the VOR suggest that suppression of the “integrative (position) loop” of the VOR circuit was more complete than suppression of the direct, “velocity” pathway.

A high‐frequency sparker source for the borehole environment

Geophysics ◽  
1993 ◽  
Vol 58 (5) ◽  
pp. 660-669 ◽  
Author(s):  
Richard D. Rechtien ◽  
K. L. Hambacker ◽  
R. F. Ballard
Keyword(s):  
High Frequency ◽  
Arc Discharge ◽  
Signal To Noise Ratio ◽  
Salt Water ◽  
Low Cost ◽  
Vertical Plane ◽  
Seismic Source ◽  
Coaxial Cable ◽  
Signal To Noise ◽  
Noise Ratio

For tomographic investigations of shallow subsurface features of limited lateral extent, a high‐frequency, low‐cost borehole seismic source would be highly desirable, particularly for investigators with limited budgets. We constructed a simple, arc‐discharge seismic source from off‐the‐shelf items. This source consists of a salt water filled bottle containing exposed conductors of a coaxial cable, across which 100 to 300 joules of electrical power were discharged. This source produced a seismic pulse with a dominant frequency in the neighborhood of 1.5 kHz and a half‐power bandwidth in excess of 1 kHz. Repeatability of seismic signatures in a variety of environmental settings was excellent. Sufficient power was generated to observe seismic signals with at least a 35 dB signal‐to‐noise ratio at horizontal borehole separations of 100 m. For a borehole separation of 33.2 m, signals with at least a 35 dB signal‐to‐noise ratio were observed at angular ranges in the vertical plane to 68 degrees. The hydrostatic head limit for this source was determined to be approximately 430 m.

scholarly journals The Effects of Hearing Impairment, Age, and Hearing Aids on the Use of Self-Motion for Determining Front/Back Location

2016 ◽  
Vol 27 (07) ◽  
pp. 588-600 ◽  
Author(s):  
W. Owen Brimijoin ◽  
Michael A. Akeroyd
Keyword(s):  
Hearing Impairment ◽  
Hearing Aids ◽  
Sound Source ◽  
High Frequency ◽  
Source Location ◽  
Hearing Impaired ◽  
Motion Processing ◽  
Binaural Cues ◽  
Spectral Cues ◽  
Self Motion

Background: There are two cues that listeners use to disambiguate the front/back location of a sound source: high-frequency spectral cues associated with the head and pinnae, and self-motion–related binaural cues. The use of these cues can be compromised in listeners with hearing impairment and users of hearing aids. Purpose: To determine how age, hearing impairment, and the use of hearing aids affect a listener’s ability to determine front from back based on both self-motion and spectral cues. Research Design: We used a previously published front/back illusion: signals whose physical source location is rotated around the head at twice the angular rate of the listener’s head movements are perceptually located in the opposite hemifield from where they physically are. In normal-hearing listeners, the strength of this illusion decreases as a function of low-pass filter cutoff frequency, this is the result of a conflict between spectral cues and dynamic binaural cues for sound source location. The illusion was used as an assay of self-motion processing in listeners with hearing impairment and users of hearing aids. Study Sample: We recruited 40 hearing-impaired participants, with an average age of 62 yr. The data for three listeners were discarded because they did not move their heads enough during the experiment. Data Collection and Analysis: Listeners sat at the center of a ring of 24 loudspeakers, turned their heads back and forth, and used a wireless keypad to report the front/back location of statically presented signals and of dynamically moving signals with illusory locations. Front/back accuracy for static signals, the strength of front/back illusions, and minimum audible movement angle were measured for each listener in each condition. All measurements were made in each listener both aided and unaided. Results: Hearing-impaired listeners were less accurate at front/back discrimination for both static and illusory conditions. Neither static nor illusory conditions were affected by high-frequency content. Hearing aids had heterogeneous effects from listener to listener, but independent of other factors, on average, listeners wearing aids exhibited a spectrally dependent increase in “front” responses: the more high-frequency energy in the signal, the more likely they were to report it as coming from the front. Conclusions: Hearing impairment was associated with a decrease in the accuracy of self-motion processing for both static and moving signals. Hearing aids may not always reproduce dynamic self-motion–related cues with sufficient fidelity to allow reliable front/back discrimination.

scholarly journals Vertical-plane sound localization with distorted spectral cues

2013 ◽  
Vol 306 ◽  
pp. 76-92 ◽  
Author(s):  
Ewan A. Macpherson ◽  
Andrew T. Sabin
Keyword(s):  
Sound Localization ◽  
Vertical Plane ◽  
Spectral Cues ◽  
Plane Sound

A High Performance Energy Analyzer for Use in Electron Scanning Microscopy

1969 ◽  
Vol 27 ◽  
pp. 14-15
Author(s):  
A. V. Crewe ◽  
M. Isaacson ◽  
D. Johnson
Keyword(s):  
High Performance ◽  
Vertical Plane ◽  
Median Plane ◽  
Electron Gun ◽  
Uniform Field ◽  
Loss Mechanism ◽  
Electron Scanning Microscopy ◽  
Sector Type ◽  
Double Focusing ◽  
Electron Energy Loss

A double focusing magnetic spectrometer has been constructed for use with a field emission electron gun scanning microscope in order to study the electron energy loss mechanism in thin specimens. It is of the uniform field sector type with curved pole pieces. The shape of the pole pieces is determined by requiring that all particles be focused to a point at the image slit (point 1). The resultant shape gives perfect focusing in the median plane (Fig. 1) and first order focusing in the vertical plane (Fig. 2).

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