scholarly journals Detection Thresholds for Combined Infrasound and Audio-Frequency Stimuli

2019 ◽  
Vol 105 (6) ◽  
pp. 1173-1182 ◽  
Author(s):  
Elisa Burke ◽  
Johannes Hensel ◽  
Thomas Fedtke ◽  
Stefan Uppenkamp ◽  
Christian Koch
Keyword(s):  
Detection Threshold ◽  
Stimulus Frequency ◽  
The Other ◽  
Pink Noise ◽  
Audio Frequency ◽  
Frequency Range ◽  
Sensation Level ◽  
Noise Stimulus ◽  
Detection Thresholds ◽  
Threshold Levels

This study investigated whether the presence of audio sound (20 Hz < frequency f < 20 kHz) influences the detection threshold for infrasound (f < 20 Hz), and, vice versa, whether the presence of infrasound influences the detection threshold for audio sound. Monaural detection thresholds of thirteen otologically normal listeners were repeatedly determined for infrasound stimuli (sinusoids at 5 Hz and at 12 Hz) and for audio sound stimuli (sinusoids and bandlimited pink noise), separately and in presence of the respective other sound type. The measurements were performed with an adaptive 1-up-2-down 3-alternative forced-choice (3-AFC) procedure. Threshold levels for infrasound stimuli were not affected by audio sound at +5 dB sensation level (SL), but they were significantly increased by the presence of some of the audio sound stimuli presented at +50 dB SL. For example, thresholds for the detection of infrasound increased on average by around 5 dB when simultaneously presented with a pink-noise stimulus (frequency range: 250 Hz– 4000 Hz). On the other hand, the presence of infrasound with levels up to +10 dB SL did not cause any significant change in the detection thresholds for audio sound. This could be an indication that infrasound might even be more annoying in a quiet environment.

scholarly journals A psychoacoustical study to investigate the perceived unpleasantness of infrasound combined with audio-frequency sound

Acta Acustica ◽  
2020 ◽  
Vol 4 (5) ◽  
pp. 20
Author(s):  
Elisa Burke ◽  
Stefan Uppenkamp ◽  
Christian Koch
Keyword(s):  
Auditory Perception ◽  
Detection Threshold ◽  
Pairwise Comparison ◽  
Audio Frequency ◽  
Frequency Range ◽  
Comparison Task ◽  
Simultaneous Exposure ◽  
Large Variability ◽  
Numerical Scale ◽  
The Common

At many immission sites of infrasound (frequency f < 20 Hz), humans are exposed to a mixture of infrasound and sound in the common audio-frequency range (audio sound, 20 Hz < f < 20 kHz). Therefore, the purpose of this study was to examine the auditory perception of infrasound and audio sound not only in isolation but also in combination. This laboratory study aims to investigate the perceived unpleasantness of infrasound (sinusoid at 12 Hz) and audio sound (sinusoid at 1000 Hz, pink-noise 250–4000 Hz), presented alone or in combination with each other. A pairwise comparison task and a rating task using a numerical scale were conducted with 19 normal hearing listeners. In addition, individual detection thresholds were determined for the infrasound stimulus. Combinations of infrasound and audio sound were rated as equally or more unpleasant than either sound presented alone. Inter-individual differences in unpleasantness ratings using the numerical scale were particularly high for stimuli containing infrasound. This can only in part be related to the large variability in infrasound thresholds. These findings suggest that simultaneous exposure to infrasound and audio sound can increase the perceived unpleasantness when both are presented at a sufficient level above the detection threshold.

On the calculation of AFMAG *AFMAG—Audio Frequency Magnetics.anomalies

Geophysics ◽  
1960 ◽  
Vol 25 (6) ◽  
pp. 1290-1293
Author(s):  
JAMES Richard WAIT
Keyword(s):  
Geomagnetic Field ◽  
The Other ◽  
Earth’S Crust ◽  
Audio Frequency ◽  
Geophysical Prospecting ◽  
Frequency Range ◽  
Horizontal Stratification ◽  
Charles Wright ◽  
Earth's Crust ◽  
Practical Scheme

It has been proposed by S. H. Ward (1959) and C. S. Wright et al. (1960) that nonuniformity in the earth's crust will tend to tilt the direction of the fluctuating components of the geomagnetic field from its normal horizontal direction. In fact, Ward and colleagues have developed a practical scheme (AFMAG) for geophysical prospecting which makes use of this phenomenon in the frequency range from 100 to 400 c/s. Sir Charles Wright et al., on the other hand, have found that at much lower frequencies, .005 to 1 c/s, a substantial verticalcomponent of the field in the vicinity of coast lines or other situations where the earth's crust departs from horizontal stratification.

scholarly journals Dielectric anomalies of solid CO and N2 in the audio frequency range

1999 ◽  
Vol 256 (1) ◽  
pp. 75-80 ◽  
Author(s):  
S. Pilla ◽  
J.A. Hamida ◽  
K.A. Muttalib ◽  
N.S. Sullivan
Keyword(s):  
Audio Frequency ◽  
Frequency Range ◽  
Audio Frequency Range

The relationship between group velocity and phase velocity for finite, discrete observations

1977 ◽  
Vol 67 (5) ◽  
pp. 1249-1258
Author(s):  
Douglas C. Nyman ◽  
Harsh K. Gupta ◽  
Mark Landisman
Keyword(s):  
Phase Velocity ◽  
Group Velocity ◽  
The Other ◽  
Frequency Range ◽  
Finite Frequency ◽  
Discrete Observations ◽  
Practical Situation ◽  
Order Polynomial ◽  
Observational Errors ◽  
The Relationship

abstract The well-known relationship between group velocity and phase velocity, 1/u = d/dω (ω/c), is adapted to the practical situation of discrete observations over a finite frequency range. The transformation of one quantity into the other is achieved in two steps: a low-order polynomial accounts for the dominant trends; the derivative/integral of the residual is evaluated by Fourier analysis. For observations of both group velocity and phase velocity, the requirement that they be mutually consistent can reduce observational errors. The method is also applicable to observations of eigenfrequency and group velocity as functions of normal-mode angular order.

How to use body tilt for the simulation of linear self motion

2004 ◽  
Vol 14 (5) ◽  
pp. 375-385 ◽  
Author(s):  
E.L. Groen ◽  
W. Bles
Keyword(s):  
Visual Motion ◽  
Detection Threshold ◽  
Stimulus Frequency ◽  
Flight Simulation ◽  
Body Tilt ◽  
Whole Body ◽  
Motion Percept ◽  
Self Motion ◽  
Rate Limit ◽  
Pitch Tilt

We examined to what extent body tilt may augment the perception of visually simulated linear self acceleration. Fourteen subjects judged visual motion profiles of fore-aft motion at four different frequencies between 0.04âĂŞ0.33 Hz, and at three different acceleration amplitudes (0.44, 0.88 and 1.76 m / s 2 ). Simultaneously, subjects were tilted backward and forward about their pitch axis. The amplitude of pitch tilt was systematically varied. Using a two-alternative-forced-choice paradigm, psychometric curves were calculated in order to determine: 1) the minimum tilt amplitude required to generate a linear self-motion percept in more than 50% of the cases, and 2) the maximum tilt amplitude at which rotation remains sub-threshold in more than 50% of the cases. The results showed that the simulation of linear self motion became more realistic with the application of whole body tilt, as long as the tilt rate remained under the detection threshold of about 3 deg/s. This value is in close agreement with the empirical rate limit commonly used in flight simulation. The minimum required motion cue was inversely proportional to stimulus frequency, and increased with the amplitude of the visual displacement (rather than acceleration). As a consequence, the range of useful tilt stimuli became more critical with increasing stimulus frequency. We conclude that this psychophysical approach reveals valid parameters for motion driving algorithms used in motion base simulators.

scholarly journals Ejaculatory Pain

2007 ◽  
Vol 107 (2) ◽  
pp. 298-304 ◽  
Author(s):  
Eske K. Aasvang ◽  
Bo Møhl ◽  
Henrik Kehlet
Keyword(s):  
Chronic Pain ◽  
Sexual Dysfunction ◽  
Quantitative Sensory Testing ◽  
Groin Hernia ◽  
Pain Treatment ◽  
Detection Threshold ◽  
Control Group ◽  
Sensory Testing ◽  
Detection Thresholds ◽  
Pain Detection

Background Sexual dysfunction due to ejaculatory and genital pain after groin hernia surgery may occur in approximately 2.5% of patients. However, the specific psychosexological and neurophysiologic characteristics have not been described, thereby precluding assessment of pathogenic mechanisms and treatment strategies. Methods Ten patients with severe pain-related sexual dysfunction and ejaculatory pain were assessed in detail by quantitative sensory testing and interviewed by a psychologist specialized in evaluating sexual functional disorders and were compared with a control group of 20 patients with chronic pain after groin hernia repair but without sexual dysfunction, to identify sensory changes associated with ejaculatory pain. Results Quantitative sensory testing showed significantly higher thermal and mechanical detection thresholds and lowered mechanical pain detection thresholds in both groups compared with the nonpainful side. Pressure pain detection threshold and tolerance were significantly lower in the ejaculatory pain group compared with the control group. 'The maximum pain was specifically located at the external inguinal annulus in all ejaculatory pain patients, but not in controls. The psychosexual interview revealed no major psychosexual disturbances and concluded that the pain was of somatic origin. All patients with ejaculatory pain had experienced major negative life changes and deterioration in their overall quality of life and sexual function as a result of the hernia operation. Conclusions Postherniotomy ejaculatory pain and pain-related sexual dysfunction is a specific chronic pain state that may be caused by pathology involving the vas deferens and/or nerve damage. Therapeutic strategies should therefore include neuropathic pain treatment and/or surgical exploration.

scholarly journals Is Peripheral Motion Detection Affected by Myopia?

2021 ◽  
Vol 15 ◽  
Author(s):  
Junhan Wei ◽  
Deying Kong ◽  
Xi Yu ◽  
Lili Wei ◽  
Yue Xiong ◽  
...  
Keyword(s):  
Visual Field ◽  
Spatial Frequency ◽  
Motion Detection ◽  
High Speed ◽  
Detection Threshold ◽  
High Spatial Frequency ◽  
Spherical Equivalent ◽  
Detection Thresholds ◽  
Significant Difference ◽  
Motion Speed

PurposeThe current study was to investigate whether myopia affected peripheral motion detection and whether the potential effect interacted with spatial frequency, motion speed, or eccentricity.MethodsSeventeen young adults aged 22–26 years participated in the study. They were six low to medium myopes [spherical equivalent refractions −1.0 to −5.0 D (diopter)], five high myopes (&lt;-5.5 D) and six emmetropes (+0.5 to −0.5 D). All myopes were corrected by self-prepared, habitual soft contact lenses. A four-alternative forced-choice task in which the subject was to determine the location of the phase-shifting Gabor from the four quadrants (superior, inferior, nasal, and temporal) of the visual field, was employed. The experiment was blocked by eccentricity (20° and 27°), spatial frequency (0.6, 1.2, 2.4, and 4.0 cycles per degree (c/d) for 20° eccentricity, and 0.6, 1.2, 2.0, and 3.2 c/d for 27° eccentricity), as well as the motion speed [2 and 6 degree per second (d/s)].ResultsMixed-model analysis of variances showed no significant difference in the thresholds of peripheral motion detection between three refractive groups at either 20° (F[2,14] = 0.145, p = 0.866) or 27° (F[2,14] = 0.475, p = 0.632). At 20°, lower motion detection thresholds were associated with higher myopia (p &lt; 0.05) mostly for low spatial frequency and high-speed targets in the nasal and superior quadrants, and for high spatial frequency and high-speed targets in the temporal quadrant in myopic viewers. Whereas at 27°, no significant correlation was found between the spherical equivalent and the peripheral motion detection threshold under all conditions (all p &gt; 0.1). Spatial frequency, speed, and quadrant of the visual field all showed significant effect on the peripheral motion detection threshold.ConclusionThere was no significant difference between the three refractive groups in peripheral motion detection. However, lower motion detection thresholds were associated with higher myopia, mostly for low spatial frequency targets, at 20° in myopic viewers.

scholarly journals The comparison of gains prescribed for digital behind-the-ear hearing aids using the manufacturer-specific and conventional prescriptive formulas

2021 ◽  
Author(s):  
Shahin Shyekhaghaei ◽  
Seyyed Jalal Sameni ◽  
Nariman Rahbar
Keyword(s):  
Hearing Loss ◽  
Hearing Aids ◽  
Input Output ◽  
Frequency Range ◽  
Sensation Level ◽  
Input Intensity ◽  
Multi Stage ◽  
Significant Difference ◽  
Different Levels ◽  
Frequency Intensity

Background and Aim: There are several prescriptive formulas for covering a variety of hearing loss, each of which applies relatively different amplifications at different frequencies. This study aims to compare the gains prescribed for digital behind-the-ear (BTE) hearing aids by the Desired Sensation Level Multi-Stage [Input/Output] (DSLm[I/O]), National Acoustic Laboratories-non linear2 (NAL-NL2) and manufacturer-specific formulas at different levels of input intensity. Methods: The gain values in 12-channel BTE hearing aids prepared from four companies (Oticon, Phonak, ReSound and Siemens) were measured at three levels of input intensity (45, 65, and 85 dB SPL) and at a frequency range of 250−8000 Hz for two moderately severe flat and mild sloping to severe hearing losses by using the DSLm[I/O], NAL-NL2 and manufacturerspecific formulas in the Frye FP35 test box. Results: There was no significant difference between the four selected hearing aids in terms of prescribed gain values using the prescriptive formulas (p > 0.05). Conclusion: The DSLm[I/O] formula prescribes higher gain in the 12-channel BTE hearing aids from Oticon, Phonak and Siemens companies at all input intensities and frequencies for moderately severe flat and mild sloping to severe hearing losses compared to the NAL-NL2 formula and manufacturer-specific formulas (Voice Aligned Compression (VAC), Adaptive Phonak, Connexx Fit and audiogram+). Keywords: National acoustic laboratories-non linear2; desired sensation level multi-stage [input/output]; gain; frequency; intensity levels

scholarly journals A.C conductivity and dielectric properties of (PVA/ PEO) blends doped with MWCNTs

2019 ◽  
Vol 14 (30) ◽  
pp. 64-72
Author(s):  
Ahmad A. Hasan
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Properties ◽  
The Other ◽  
Poly Vinyl Alcohol ◽  
Conductivity Measurements ◽  
Frequency Range ◽  
Maximum Value ◽  
Multi Walled Carbon Nanotube ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

A.C electrical conductivity and dielectric properties for poly(vinyl alcohol) (PVA) /poly (ethylene oxide) (PEO) blends undopedand doped with multi-walled carbon nanotube (MWCNTs) withdifferent concentrations (1, and 3 wt %) in the frequency range(25x103 - 5x106 Hz) were investigated. Samples of (PVA/PEO)blends undoped and doped with MWCNTs were prepared usingcasting technique. The electrical conductivity measurements showedthat σA.C is frequency dependent and obey the relation σA.C =Aωs forundoped and doped blends with 1% MWCNTs, while it is frequencyindependent with increases of MWCNTs content to 3%. Theexponent s showed proceeding increase with the increase of PEOratio (≥50%) for undoped blends samples, while s value for dopedblends exhibits to change in different manner, i.e. s increases andreach maximum value at 50/50 PVA/PEO, then decreases forresidual doped blends samples with 1% MWCNTs on the other handthe exponent s decrease and reach minimum value at 50/50PVA/PEO for samples doped with 3% MWCNTs, then return toincrease. The results explained in different terms.

Sign in / Sign up

Export Citation Format

Share Document