Sound propagation in rigid bends: A multimodal approach

2001 ◽  
Vol 110 (3) ◽  
pp. 1329-1337 ◽  
Author(s):  
S. Félix ◽  
V. Pagneux
2019 ◽  
Vol 875 ◽  
pp. 411-447
Author(s):  
James P. McTavish ◽  
Edward J. Brambley

A method for studying weakly nonlinear acoustic propagation in two-dimensional ducts of general shape – including curvature and variable width – is presented. The method is based on a local modal decomposition of the pressure and velocity in the duct. A pair of nonlinear ordinary differential equations for the modal amplitudes of the pressure and velocity modes is derived. To overcome the inherent instability of these equations, a nonlinear admittance relation between the pressure and velocity modes is presented, introducing a novel ‘nonlinear admittance’ term. Appropriate equations for the admittance are derived which are to be solved through the duct, with a radiation condition applied at the duct exit. The pressure and velocity are subsequently found by integrating an equation involving the admittance through the duct. The method is compared, both analytically and numerically, against published results and the importance of nonlinearity is demonstrated in ducts of complex geometry. Comparisons between ducts of differing geometry are also performed to illustrate the effect of geometry on nonlinear sound propagation. A new ‘nonlinear reflectance’ term is introduced, providing a more complete description of acoustic reflection that also takes into account the amplitude of the incident wave.


2020 ◽  
Vol 29 (4) ◽  
pp. 2109-2130
Author(s):  
Lauren Bislick

Purpose This study continued Phase I investigation of a modified Phonomotor Treatment (PMT) Program on motor planning in two individuals with apraxia of speech (AOS) and aphasia and, with support from prior work, refined Phase I methodology for treatment intensity and duration, a measure of communicative participation, and the use of effect size benchmarks specific to AOS. Method A single-case experimental design with multiple baselines across behaviors and participants was used to examine acquisition, generalization, and maintenance of treatment effects 8–10 weeks posttreatment. Treatment was distributed 3 days a week, and duration of treatment was specific to each participant (criterion based). Experimental stimuli consisted of target sounds or clusters embedded nonwords and real words, specific to each participants' deficit. Results Findings show improved repetition accuracy for targets in trained nonwords, generalization to targets in untrained nonwords and real words, and maintenance of treatment effects at 10 weeks posttreatment for one participant and more variable outcomes for the other participant. Conclusions Results indicate that a modified version of PMT can promote generalization and maintenance of treatment gains for trained speech targets via a multimodal approach emphasizing repeated exposure and practice. While these results are promising, the frequent co-occurrence of AOS and aphasia warrants a treatment that addresses both motor planning and linguistic deficits. Thus, the application of traditional PMT with participant-specific modifications for AOS embedded into the treatment program may be a more effective approach. Future work will continue to examine and maximize improvements in motor planning, while also treating anomia in aphasia.


Skull Base ◽  
2007 ◽  
Vol 16 (S 1) ◽  
Author(s):  
Anthony Zeitouni ◽  
Richard Leblanc ◽  
Peter Abou Jaoude ◽  
Labib Soualmi

2012 ◽  
Vol 6 (1) ◽  
pp. 47-63
Author(s):  
Stephen Pihlaja

Using membership categorization analysis, this article investigates membership categories in a YouTube video made by an Evangelical Christian in which he differentiates between “saved” and “religious” users. Analysis will take a discourse-centred, multimodal approach grounded in longitudinal observation, using analysis of video discourse to instruct analysis of video images and user comments. Findings will show that categorization is accomplished by using recognized categories with ambiguous descriptions of category-bound activities that include metaphors, such as “being hungry for God” and not “hanging out with atheists.” These categories are recognized by commenters on the video, but the category bound activities applied to the category members are disputed. Findings will also show that scriptural reference plays an important role in categorization in the video, drawing on direct Bible quotes as well as paraphrases of key passages.


2017 ◽  
Vol 13 (1) ◽  
pp. 4522-4534
Author(s):  
Armando Tomás Canero

This paper presents sound propagation based on a transverse wave model which does not collide with the interpretation of physical events based on the longitudinal wave model, but responds to the correspondence principle and allows interpreting a significant number of scientific experiments that do not follow the longitudinal wave model. Among the problems that are solved are: the interpretation of the location of nodes and antinodes in a Kundt tube of classical mechanics, the traslation of phonons in the vacuum interparticle of quantum mechanics and gravitational waves in relativistic mechanics.


AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 768-773 ◽  
Author(s):  
Yusuf Ozyoruk ◽  
Lyle N. Long

1989 ◽  
Author(s):  
EDMOND LO ◽  
R. FERGUSON ◽  
MICHAEL FRISH ◽  
PETERE. NEBOLSINE
Keyword(s):  

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