Acoustic Component

2016 ◽  
Author(s):  
Masahide Terazima ◽  
Noboru Hirota ◽  
Silvia E. Braslavsky ◽  
Andreas Mandelis ◽  
Stephen E. Bialkowski ◽  
...  
Keyword(s):  
Acoustic Component

A Role for Acoustic Stimulation in Advanced Otosclerosis: Direct Acoustic Cochlear Implant versus Cochlear Implant

2018 ◽  
Vol 23 (2) ◽  
pp. 89-97
Author(s):  
Nicolas Verhaert ◽  
Charlotte Borgers ◽  
Katleen De Voecht ◽  
Ellen Boon ◽  
Christian Desloovere
Keyword(s):  
Speech Perception ◽  
Cochlear Implant ◽  
Hearing Aids ◽  
Standard Treatment ◽  
Acoustic Stimulation ◽  
Grading System ◽  
Effective Treatment Option ◽  
Computed Tomographic ◽  
Direct Acoustic Cochlear Implant ◽  
Acoustic Component

Recent findings support the efficacy of the direct acoustic cochlear implant (DACI) in patients with advanced otosclerosis whose rehabilitation is very challenging. Standard treatment consists of stapes surgery combined with hearing aids or a cochlear implant (CI). CI surgery, however, is often challenging depending on the grade of otosclerosis. This study aims to compare speech perception scores in quiet and noise of 6 DACI and 12 CI patients with advanced otosclerosis at 3 and 12 months after fitting. Preoperative computed tomographic scans of all patients were scored by experts using an existing otosclerosis grading system (stages 1–3). Speech perception in quiet was significantly better for DACI compared to CI users at 3 months after fitting. At 12 months, no difference was found between DACI and CI patients. Speech perception scores in noise were significantly better in the DACI group. In summary, a DACI system seems to provide an effective treatment option as the acoustic component can be preserved in patients with advanced otosclerosis.

The acoustic component of western consonance

Interface ◽  
1978 ◽  
Vol 7 (1) ◽  
pp. 1-29 ◽  
Author(s):  
William Hutchinson ◽  
Leon Knopoff
Keyword(s):  
Acoustic Component

Transmission of energy down periodically ribbed elastic structures under fluid loading

1984 ◽  
Vol 394 (1807) ◽  
pp. 405-436 ◽  
Keyword(s):  
Surface Wave ◽  
Long Range ◽  
Formal Solution ◽  
Stop Band ◽  
Elastic Membrane ◽  
Wave Component ◽  
Fluid Loading ◽  
Heavy Fluid ◽  
Resonance Frequencies ◽  
Acoustic Component

The paper studies a model configuration in which an elastic membrane is immersed in static compressible fluid, excited by a time-harmonic line force and supported by a periodic array of line supports (ribs) of infinite mechanical impedance. At the driven rib the velocity has a prescribed value V 0 , while the velocities vanish at the locations, x = nh ( n = ± 1, ± 2,. . .), of the supporting ribs. Fluid loading provides the only coupling between adjacent bays, and the aim is to expose the dual role of that coupling (local and long range) in the transmission of energy from the excitation to infinity along the structure and to the acoustic radiation field. This transmission is characterized by the variation with n of the force F n exerted on the structure by the n th rib. An exact formal solution is obtained for F n in terms of the Green function G(x) of the unribbed fluid-loaded structure, and explicit expressions are obtained for F n when only the subsonic surface wave component, G s ( x ), is included in G(x) (though with full account of fluid loading in G s ( x ) itself). These expressions show that under ‘significant’ and ‘heavy’ fluid loading (terms made precise in the text), fluid loading in the form of subsonic surface waves provides a local bay-to-bay coupling very much like that of an imperfect mechanical isolation, and induces a pass and stop band structure of the kind familiar from other studies of wave propagation in mechanically-coupled periodic structures in the absence of fluid loading. Under ‘light’ fluid loading it is shown that there can be no strict pass bands, but frequency bands around the vacuum bay resonance frequencies are identified within which the energy decay rate along the structure is very slow. In all these calculations the fate of the power injected by the excitation is followed in all detail, whether to infinity in the structure or to infinity in the acoustic field. The acoustic component G a ( x ) is then included, and specific asymptotic expressions for G a ( x ) are used to deal with the light and heavy fluidloading cases. These expressions for G a ( x ) involve slow algebraic decay with x , and induce a generally similar decay of the F n with n . In this sense, the acoustic component G a ( x ) provides a long-range coupling between the driven rib and distant ribs which, in the stop bands, is much stronger than the exponentially weak coupling provided by the surface wave component G s ( x ). Numerical estimates are given which indicate that in both light and heavy fluid loading the acoustic component of the force F n exceeds the surface wave component once n exceeds a very modest value. The paper ends with a discussion of the possible implications for structure-borne noise control in periodic fluid-loaded structures, for the application of Statistical Energy Analysis to structures under fluid loading, and for the relevance of the ideas of Anderson localization in an irregular structure under fluid loading.

scholarly journals On the improvement of accommodation to non-individual HRTFs via VR active learning and inclusion of a 3D room response

Acta Acustica ◽  
2021 ◽  
Vol 5 ◽  
pp. 25
Author(s):  
David Poirier-Quinot ◽  
Brian F.G. Katz
Keyword(s):  
Active Learning ◽  
Training Program ◽  
Spatial Cues ◽  
Learning Rates ◽  
Localization Performance ◽  
Improved Learning ◽  
The Impact ◽  
Acoustic Component ◽  
Training Protocol ◽  
Selection Of

This study examines the efficiency of a training protocol using a virtual reality application designed to accelerate individual’s selection of, and accommodation to, non-individualized HRTF profiles. This training introduces three elements to hasten audio localization performance improvement: an interactive HRTF selection method, a parametric training program based on active learning, and a relatively dry room acoustic simulation designed to increase the quantity of spatial cues presented. Participants rapidly selected an HRTF (≈5 min) followed by training over three sessions of 12 min distributed over 5 days. To study the impact of the room acoustic component on localization performance evolution, participants were divided into two groups: one acting as control reference, training with only anechoic renderings, the other training in reverberant conditions. The efficiency of the training program was assessed across groups and the entire protocol was assessed through direct comparisons with results reported in previous studies. Results indicate that the proposed training program led to improved learning rates compared to that of previous studies, and that the included room response accelerated the learning process.

scholarly journals Study on Radiated Noise of a Panel under Fluctuating Surface Pressure Due to an Idealized Side Mirror

2020 ◽  
Vol 10 (3) ◽  
pp. 994
Author(s):  
Jianwang Shao ◽  
Jinmeng Yang ◽  
Xian Wu ◽  
Cheng Wang ◽  
Guoming Deng
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Interior Noise ◽  
Computational Time ◽  
Vehicle Interior ◽  
Radiated Noise ◽  
Vehicle Interior Noise ◽  
Force Coupling ◽  
Modal Force ◽  
Acoustic Component

As traditional automobiles develop towards new energy vehicles, the noise, vibration and harshness (NVH) performance of automobiles is facing new challenges. Without the cover of the traditional engine noise and inlet and exhaust noise, the high-speed wind noise becomes more prominent. Thus, research on the calculation method of vehicle interior noise in high-speed driving condition is needed. However, vehicle body structure is complex, and the external excitation components are complicated. In order to analyze the method of predicting the vehicle interior noise at high speed, an idealized side mirror model is taken as the research object in this paper and the radiated noise of a panel under the fluctuating surface pressure (FSP) due to the idealized side mirror is studied. The FSP of the panel is first studied by the numerical simulations of incompressible and compressible flow field. For the incompressible flow field, the Corcos turbulent boundary layer (TBL) model is established to simulate the convective component and the boundary element method (BEM) is used to extract the acoustic component. Subsequently, the Corcos model coupling BEM method, the random modal force coupling BEM method and the deterministic modal force coupling BEM method are used separately to calculate the noise of the panel under the FSP. For the compressible flow field, the convective and acoustic component in the fluctuating pressure are separated by the wavenumber-frequency spectrum (WFS) method. The radiated noise of the panel under the FSP is calculated again by using the WFS, the method of random modal force and the method of deterministic modal force, respectively. Then, the computational time of the six methods of incompressible and compressible calculation is compared. Finally, a fast and accurate method of calculating the panel radiated noise under FSP is obtained by comparing the computational accuracy with the experimental results and combining the computational time: the method of incompressible random modal force. This method can be used to quickly and accurately analyze the vehicle interior noise at high speed, and to optimize the exterior protrusions and the vehicle sound package for improving the vehicle NVH performance at high speed.

Acoustical signals related to reproduction in the spinulosus species group of Bufo (Amphibia, Bufonidae)

1981 ◽  
Vol 59 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Mario V. Penna ◽  
Alberto M. Veloso
Keyword(s):  
Physiological State ◽  
Interspecific Variation ◽  
Reproductive Activity ◽  
Species Group ◽  
Evolutionary Divergence ◽  
Recognition Mechanism ◽  
Mating Call ◽  
Species Specific ◽  
Acoustical Signals ◽  
Acoustic Component

Species of the spinulosus group of Bufo, B. chilensis, B. atacamensis, and B. spinulosus, do not emit a mating call during their reproductive activity. A release call is emitted by clasped males and the acoustic component of this signal produces rejection of the clasping male. Temporal and spectral analysis shows that these signals are species specific and therefore a useful complement in taxonomic diagnosis of these species. The release call is also emitted by B. spinulosus without contact with other individuals. This suggests that the signal is also a distance-recognition mechanism. During amplexus, B. chilensis and B. atacamensis emit vocalizations not reported for another Bufo species. Its significance has not been established and can represent a release-call modification during a particular physiological state of the animal. Interspecific variation of vocalizations in the spinulosus group is evidence to support the speciation model proposed for the group. Bufo spinulosus has the most divergent signal. Bufo chilensis and B. atacamensis are more related species and their evolutionary divergence is a later event in the radiation of the genus.

Factor Analysis of Vowel Pronunciation in Swedish Dialects

2008 ◽  
Vol 2 (1-2) ◽  
pp. 189-204 ◽  
Author(s):  
Therese Leinonen
Keyword(s):  
Principal Component Analysis ◽  
Factor Analysis ◽  
Principal Component ◽  
Distribution Patterns ◽  
Factor Scores ◽  
Vowel Quality ◽  
Acoustic Measurements ◽  
Linguistic Features ◽  
Strong Resemblance ◽  
Acoustic Component

In this study 91 local Swedish dialects were analysed based on vowel pronunciation. Acoustic measurements of vowel quality were made for 18 vowels of 1,014 speakers by means of principal component analysis of vowel spectra. Two principal components were extracted explaining more than [Formula: see text] of the total variance in the vowel spectra. Plotting vowels in the PC1-PC2 plane showed a solution with strong resemblance to vowels in a formant plane. Per location averages of all speakers were calculated and factor analysis was run with the 91 locations as data cases and the two acoustic component of the 18 words as variables. Nine factors were extracted corresponding to distinct geographic distribution patterns. The factor scores of the analysis revealed co-occurrence of a number of linguistic features.

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