Canadian Acoustics //jcaa.caa-aca.ca/index.php/jcaa <p>This quarterly journal is free to individual members of the Canadian Acoustical Association (CAA) and institutional subscribers. <strong>Canadian Acoustics</strong> publishes refereed articles and news items on all aspects of acoustics and vibration. It also includes information on research, reviews, news, employment, new products, activities, discussions, etc. Papers reporting new results and applications, as well as review or tutorial papers and shorter research notes are welcomed, in English or in French.</p> en-US <p>Copyright on articles is held by the author(s). The corresponding author has the right to grant on behalf of all authors and does grant on behalf of all authors, a worldwide exclusive licence (or non-exclusive license for government employees) to the Publishers and its licensees in perpetuity, in all forms, formats and media (whether known now or created in the future) <br>i)&nbsp;&nbsp; &nbsp;to publish, reproduce, distribute, display and store the Contribution;<br>ii)&nbsp;&nbsp; &nbsp;to translate the Contribution into other languages, create adaptations, reprints, include within collections and create summaries, extracts and/or, abstracts of the Contribution;<br>iii)&nbsp;&nbsp; &nbsp;to exploit all subsidiary rights in the Contribution,<br>iv)&nbsp;&nbsp; &nbsp;to provide the inclusion of electronic links from the Contribution to third party material where-ever it may be located;<br>v)&nbsp;&nbsp; &nbsp;to licence any third party to do any or all of the above.<br><br></p> editor@caa-aca.ca (Prof. Umberto Berardi) Tue, 07 Apr 2020 12:50:05 +0000 OJS 3.1.2.1 http://blogs.law.harvard.edu/tech/rss 60 From the Year of Sound to a 165 Hz world //jcaa.caa-aca.ca/index.php/jcaa/article/view/3381 Umberto Berardi Copyright (c) 2020 Umberto Berardi //jcaa.caa-aca.ca/index.php/jcaa/article/view/3381 Mon, 06 Apr 2020 00:00:00 +0000 ‘Butterfly acoustical skin’ – new method of reducing aero acoustical noise for a quiet propeller //jcaa.caa-aca.ca/index.php/jcaa/article/view/3283 <p>An experimental investigation was conducted on the effect ‘butterfly acoustical skin’ (metallic version of the lepidopterans scale coverage) on the acoustic performances of two - bladed propeller (diameter of 1200 mm, airfoil sections of NACA 2415, rotating speed of 1780 rpm, Re ≈ 2 × 105) in a low – speed straight through a wind tunnel. Attention was initially directed to this problem by observation of the porous scales and porous scale coverage of lepidopterans as well as other studies indicating the noise suppression of flying lepidopterans by wing appendages. The property of the moth coverage allows these insects to overcome bat attacks at night. These appendages are very small (size: 30 – 200 μm) and have a various porous structures. I discuss both many different micro – and nanostructures of the porous scales, and many differences in details among various structures of the porous scale coverage of lepidonterans. I consider here only porous scales of butterflies Papilio nireus, Nieris rapae, Deelias nigrina, male Callophrys rubi, male Polyommatus daphnis, butterfly Papilio palinurus as well as porous scale coverage of cabbage moth, moth of Saturniidae family and moth of Noctuoidea family. The evolutionary history of lepidopterans and the properties of lepidopterans scale coverage is briefly discussed as well as different methods of reducing aero acoustic noise of aircrafts.<br /><br /></p> igor kovalev Copyright (c) 2020 igor kovalev //jcaa.caa-aca.ca/index.php/jcaa/article/view/3283 Tue, 17 Mar 2020 17:43:13 +0000 Characteristics of a Cave-Style Traditional Stage in Shanxi Province, China //jcaa.caa-aca.ca/index.php/jcaa/article/view/3356 <p>Chinese traditional stages are unique in the history of the world's ancient theaters, so they have significant meaning in research on their acoustical characteristics. Among the many Chinese traditional stages, the cave-style stages and splay walls in Shanxi Province have special acoustic effects, which are simulated using a finite-difference time-domain approach in this paper. The conformal technique combined with perfectly matched layers is introduced into finite-difference time-domain equations for sound waves, which solves the acoustic problem of a curved boundary in open space. To verify the validity of the finite-difference time-domain model, simulated values are compared with measured values. Furthermore, the sound pressure distribution of several cave-style stage models and splay walls are simulated. According to the impulse responses, several room acoustical parameters, such as loudness, clarity and reverberation time, are analyzed. Moreover, a listening test based on a paired comparison method is conducted.</p> Wuqiong Huang, Yigang Lu Copyright (c) 2020 Wuqiong Huang, Yigang Lu //jcaa.caa-aca.ca/index.php/jcaa/article/view/3356 Tue, 17 Mar 2020 17:42:17 +0000 The Acoustics of the Holy Family Church in Salerno //jcaa.caa-aca.ca/index.php/jcaa/article/view/3374 <p>The church of the Holy Family in Salerno (Italy) built in 1971 radically revolutionized the spatial structure of pre-conciliar church building design. The circular stepped geometry of the roof required a complex work with the employment of shipyard workers to come out with a unique geometry. However, such futuristic geometry also resulted in challenging conditions for its acoustics, as they emerged when the construction was completed. In this paper, the results of measurements of the spatial distribution of the acoustic characteristics in this large space are reported. The analysis of the acoustic parameter values confirms the poor acoustic conditions for speech and music listening. With the help of modelling, the authors have investigated possible solutions for the acoustic correction of this modern architecture. This paper reports the conclusions of such a study.</p> Gino Iannace, Giuseppe Ciaburro, Amelia Trematerra Copyright (c) 2020 Gino Iannace, Giuseppe Ciaburro, Amelia Trematerra //jcaa.caa-aca.ca/index.php/jcaa/article/view/3374 Tue, 17 Mar 2020 17:43:33 +0000 Real-time Ultrasound-enhanced Multimodal Imaging of Tongue using 3D Printable Stabilizer System: A Deep Learning Approach //jcaa.caa-aca.ca/index.php/jcaa/article/view/3305 <pre>Despite renewed awareness of the importance of articulation, it remains a challenge for instructors to handle the pronunciation needs of language learners. There are relatively scarce pedagogical tools for pronunciation teaching and learning. Unlike inefficient, traditional pronunciation instructions like listening and repeating, electronic visual feedback (EVF) systems such as ultrasound technology have been employed in new approaches. <br>Recently, an ultrasound-enhanced multimodal method has been developed for visualizing tongue movements of a language learner overlaid on face-side of the speaker's head. That system was evaluated for several language courses via a blended learning paradigm at the university level. <br>The result was asserted that visualizing articulator’s system as biofeedback to language learners will significantly improve articulation learning efficiency. <br>In spite of that successful usage of multimodal technique for pronunciation training, it still requires manual works and human manipulation. In this article, we aim to contribute to this growing body of research by addressing difficulties of the previous approaches by proposing a new comprehensive, automatic, real-time multimodal pronunciation training system, benefits from powerful artificial intelligence techniques.<br>The main objective of this research was to combine the advantages of ultrasound technology, three-dimensional printing, and deep learning algorithms to enhance the performance of previous systems. Our preliminary pedagogical evaluation of the proposed system revealed a significant improvement in flexibility, control, robustness, and autonomy.</pre> M. Hamed Mozaffari, Won-Sook Lee Copyright (c) 2020 M. Hamed Mozaffari, Won-Sook Lee //jcaa.caa-aca.ca/index.php/jcaa/article/view/3305 Tue, 17 Mar 2020 17:42:47 +0000 Mapping a Continuous Vowel Space to Hand Gestures //jcaa.caa-aca.ca/index.php/jcaa/article/view/3373 <p>Converting hand gestures to speech sounds has been proved to be successful in Glove Talk II [Fels and Hinton, IEEE Transactions on Neural Networks, 8(5), (1997), 977]. This work mapped hand gestures to English speech sounds through an adaptive interface including gloves, space trackers and a foot-pedal. A set of hand gestures were designed and each gesture corresponded to one English segment, and apparently, users had difficulties in producing diphthongs with a natural transition. The present study aims to develop a more intuitive and compact, single-handed user interface which converts hand movements directly to a continuous formant space to generate English vowels through a formant based speech synthesizer. We have collected kinematic glove data of two participants using Cyberglove corresponding to wrist movements (up-down) and finger abduction (sideways) for 8 different English vowels as well as diphthongs. We employed a variety of deep neural networks, with varying hyperparameters, mapping the finger and wrist movements to the continuous vowel quadrilateral formant space (F1 and F2) and analysed the performance of these networks. Results demonstrated that our system achieved successful continuous mapping of one hand movements to the formant space, thereby generating English vowels accurately from a variety of hand gestures, and also showed the prospect of producing vowels of other languages.</p> Yadong Liu, Pramit Saha, Arian Shamei, Bryan Gick, Sidney Fels Copyright (c) 2020 Yadong Liu, Pramit Saha, Arian Shamei, Bryan Gick, Sidney Fels //jcaa.caa-aca.ca/index.php/jcaa/article/view/3373 Tue, 17 Mar 2020 17:41:51 +0000 Tim Kelsall Orbituary //jcaa.caa-aca.ca/index.php/jcaa/article/view/3378 Jérémie Voix Copyright (c) 2020 Jérémie Voix //jcaa.caa-aca.ca/index.php/jcaa/article/view/3378 Mon, 30 Mar 2020 19:48:48 +0000 Call for papers - Special Alberta regional journal issue //jcaa.caa-aca.ca/index.php/jcaa/article/view/3375 Jérémie Voix Copyright (c) 2020 Jérémie Voix //jcaa.caa-aca.ca/index.php/jcaa/article/view/3375 Tue, 17 Mar 2020 17:41:03 +0000 Acoustic Week in Canada 2020 Sherbrooke Conference Announcement //jcaa.caa-aca.ca/index.php/jcaa/article/view/3377 <p class="p1"><span class="s1">Acoustics Week in Canada 2020 will be held on October 7-9, in Sherbrooke, Québec.</span></p> <p class="p1"><span class="s1">&nbsp;You are invited to be part of this three-day conference featuring the latest developments in Canadian acoustics and vibration. Sherbrooke is well known in acoustics for the Groupe d’Acoustique de l’Université de Sherbrooke (GAUS) founded in 1984.</span></p> <p class="p1"><span class="s1">The conference will be an excellent opportunity to visit or rediscover the GAUS during the International Year of Sound!</span></p> Olivier Robin Copyright (c) 2020 Olivier Robin //jcaa.caa-aca.ca/index.php/jcaa/article/view/3377 Sun, 29 Mar 2020 19:57:52 +0000