Nonlinear frequency dependence of sound attenuation in sea bottoms at low frequencies

2017 ◽  
Vol 142 (4) ◽  
pp. 2621-2621
Author(s):  
Jixun Zhou ◽  
Zhenglin Li
Keyword(s):  
Frequency Dependence ◽  
Sound Attenuation ◽  
Nonlinear Frequency ◽  
Low Frequencies

The S-SH Confusion Test and the Effects of Frequency Lowering

2019 ◽  
Vol 62 (5) ◽  
pp. 1486-1505
Author(s):  
Joshua M. Alexander
Keyword(s):  
Cognitive Processing ◽  
Hearing Aids ◽  
Response Times ◽  
Nonlinear Frequency ◽  
Low Frequencies ◽  
Frequency Compression ◽  
Negative Side ◽  
Minimal Word ◽  
Low Pass ◽  
Negative Side Effects

PurposeFrequency lowering in hearing aids can cause listeners to perceive [s] as [ʃ]. The S-SH Confusion Test, which consists of 66 minimal word pairs spoken by 6 female talkers, was designed to help clinicians and researchers document these negative side effects. This study's purpose was to use this new test to evaluate the hypothesis that these confusions will increase to the extent that low frequencies are altered.MethodTwenty-one listeners with normal hearing were each tested on 7 conditions. Three were control conditions that were low-pass filtered at 3.3, 5.0, and 9.1 kHz. Four conditions were processed with nonlinear frequency compression (NFC): 2 had a 3.3-kHz maximum audible output frequency (MAOF), with a start frequency (SF) of 1.6 or 2.2 kHz; 2 had a 5.0-kHz MAOF, with an SF of 1.6 or 4.0 kHz. Listeners' responses were analyzed using concepts from signal detection theory. Response times were also collected as a measure of cognitive processing.ResultsOverall, [s] for [ʃ] confusions were minimal. As predicted, [ʃ] for [s] confusions increased for NFC conditions with a lower versus higher MAOF and with a lower versus higher SF. Response times for trials with correct [s] responses were shortest for the 9.1-kHz control and increased for the 5.0- and 3.3-kHz controls. NFC response times were also significantly longer as MAOF and SF decreased. The NFC condition with the highest MAOF and SF had statistically shorter response times than its control condition, indicating that, under some circumstances, NFC may ease cognitive processing.ConclusionsLarge differences in the S-SH Confusion Test across frequency-lowering conditions show that it can be used to document a major negative side effect associated with frequency lowering. Smaller but significant differences in response times for correct [s] trials indicate that NFC can help or hinder cognitive processing, depending on its settings.

ON THE DIELECTRIC BEHAVIOR OF LiCo3/5Fe2/5VO4 CERAMICS

2010 ◽  
Vol 24 (07) ◽  
pp. 665-670
Author(s):  
MOTI RAM
Keyword(s):  
Activation Energy ◽  
Dielectric Constant ◽  
Frequency Dependence ◽  
Chemical Method ◽  
Arrhenius Plot ◽  
Dielectric Behavior ◽  
Tangent Loss ◽  
Low Frequencies ◽  
Different Temperatures ◽  
Tan Δ

The LiCo 3/5 Fe 2/5 VO 4 ceramics has been fabricated by solution-based chemical method. Frequency dependence of the dielectric constant (εr) at different temperatures exhibits a dispersive behavior at low frequencies. Temperature dependence of εr at different frequencies indicates the dielectric anomalies in εr at Tc (transition temperature) = 190°C, 223°C, 263°C and 283°C with (εr) max ~ 5370, 1976, 690 and 429 for 1, 10, 50 and 100 kHz, respectively. Frequency dependence of tangent loss ( tan δ) at different temperatures indicates the presence of dielectric relaxation in the material. The value of activation energy estimated from the Arrhenius plot of log (τd) with 103/T is ~(0.396 ± 0.012) eV.

An Analysis of Deep Ocean Sound Attenuation at Very Low Frequencies

1982 ◽  
Author(s):  
Karl C. Focke ◽  
Stephen K. Mitchell ◽  
Sr Horton ◽  
Claude W.
Keyword(s):  
Deep Ocean ◽  
Sound Attenuation ◽  
Low Frequencies

scholarly journals Sound attenuation by conglomerates of bubbles at low frequencies

1976 ◽  
Vol 60 (S1) ◽  
pp. S35-S35
Author(s):  
K. J. Diercks ◽  
W. B. Huckabay
Keyword(s):  
Sound Attenuation ◽  
Low Frequencies

Evidence for nonlinear frequency dependence of attenuation in an East China Sea environment

2004 ◽  
Vol 115 (5) ◽  
pp. 2551-2551 ◽  
Author(s):  
David P. Knobles ◽  
Robert A. Koch ◽  
James H. Miller ◽  
Gopu R. Potty
Keyword(s):  
Frequency Dependence ◽  
East China Sea ◽  
East China ◽  
Nonlinear Frequency ◽  
China Sea

Low-frequency respiratory mechanical impedance in the rat

1987 ◽  
Vol 63 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Z. Hantos ◽  
B. Daroczy ◽  
B. Suki ◽  
S. Nagy
Keyword(s):  
Frequency Dependence ◽  
Chest Wall ◽  
Low Frequency ◽  
Mechanical Impedance ◽  
Total Resistance ◽  
Low Frequencies ◽  
Chest Wall Compliance ◽  
Before And After ◽  
Airway Opening ◽  
Wall Compliance

modified forced oscillatory technique was used to determine the respiratory mechanical impedances in anesthetized, paralyzed rats between 0.25 and 10 Hz. From the total respiratory (Zrs) and pulmonary impedance (ZL), measured with pseudorandom oscillations applied at the airway opening before and after thoracotomy, respectively, the chest wall impedance (ZW) was calculated as ZW = Zrs - ZL. The pulmonary (RL) and chest wall resistances were both markedly frequency dependent: between 0.25 and 2 Hz they contributed equally to the total resistance falling from 81.4 +/- 18.3 (SD) at 0.25 Hz to 27.1 +/- 1.7 kPa.l–1 X s at 2 Hz. The pulmonary compliance (CL) decreased mildly, from 2.78 +/- 0.44 at 0.25 Hz to 2.36 +/- 0.39 ml/kPa at 2 Hz, and then increased at higher frequencies, whereas the chest wall compliance declined monotonously from 4.19 +/- 0.88 at 0.25 Hz to 1.93 +/- 0.14 ml/kPa at 10 Hz. Although the frequency dependence of ZW can be interpreted on the basis of parallel inhomogeneities alone, the sharp fall in RL together with the relatively constant CL suggests that at low frequencies significant losses are imposed by the non-Newtonian resistive properties of the lung tissue.

Three-Dimensional Organization of Otolith-Ocular Reflexes in Rhesus Monkeys. III. Responses to Translation

1998 ◽  
Vol 80 (2) ◽  
pp. 680-695 ◽  
Author(s):  
Dora E. Angelaki
Keyword(s):  
Frequency Dependence ◽  
Brain Stem ◽  
Rhesus Monkeys ◽  
Three Dimensional ◽  
Head Orientation ◽  
Frequency Range ◽  
Low Frequencies ◽  
Similar Frequency ◽  
Response Sensitivity ◽  
Torsional Response

Angelaki, Dora E. Three-dimensional organization of otolith-ocular reflexes in rhesus monkeys. III. Responses to translation. J. Neurophysiol. 80: 680–695, 1998. The three-dimensional (3-D) properties of the translational vestibulo-ocular reflexes (translational VORs) during lateral and fore-aft oscillations in complete darkness were studied in rhesus monkeys at frequencies between 0.16 and 25 Hz. In addition, constant velocity off-vertical axis rotations extended the frequency range to 0.02 Hz. During lateral motion, horizontal responses were in phase with linear velocity in the frequency range of 2–10 Hz. At both lower and higher frequencies, phase lags were introduced. Torsional response phase changed more than 180° in the tested frequency range such that torsional eye movements, which could be regarded as compensatory to “an apparent roll tilt” at the lowest frequencies, became anticompensatory at all frequencies above ∼1 Hz. These results suggest two functionally different frequency bandwidths for the translational VORs. In the low-frequency spectrum (≪0.5 Hz), horizontal responses compensatory to translation are small and high-pass-filtered whereas torsional response sensitivity is relatively frequency independent. At higher frequencies however, both horizontal and torsional response sensitivity and phase exhibit a similar frequency dependence, suggesting a common role during head translation. During up-down motion, vertical responses were in phase with translational velocity at 3–5 Hz but phase leads progressively increased for lower frequencies (>90° at frequencies <0.2 Hz). No consistent dependence on static head orientation was observed for the vertical response components during up-down motion and the horizontal and torsional response components during lateral translation. The frequency response characteristics of the translational VORs were fitted by “periphery/brain stem” functions that related the linear acceleration input, transduced by primary otolith afferents, to the velocity signals providing the input to the velocity-to-position neural integrator and the oculomotor plant. The lowest-order, best-fit periphery/brain stem model that approximated the frequency dependence of the data consisted of a second order transfer function with two alternating poles (at 0.4 and 7.2 Hz) and zeros (at 0.035 and 3.4 Hz). In addition to clearly differentiator dynamics at low frequencies (less than ∼0.5 Hz), there was no frequency bandwidth where the periphery/brain stem function could be approximated by an integrator, as previously suggested. In this scheme, the oculomotor plant dynamics are assumed to perform the necessary high-frequency integration as required by the reflex. The detailed frequency dependence of the data could only be precisely described by higher order functions with nonminimum phase characteristics that preclude simple filtering of afferent inputs and might be suggestive of distributed spatiotemporal processing of otolith signals in the translational VORs.

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