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Kamyon, tır gibi ağır hizmet araçlarında en çok gürültü üreten yapı olan motor odasında oluşan ısı ve sesin izole edilmesi için bu yapının yakına yalıtım malzemesi olarak gürültü kalkanı konumlandırılmaktadır. Bu çalışmada, ağır hizmet araçlarında gürültü kalkanı olarak kullanılmak üzere, ses ve ısı üreten yapıya bakacak yönde konumlandırılan alt katmanda taş yünü, gürültü kalkanı parçasının mukavemet ve akustik performansını arttırmakla görevli üst katmanda PP/GF, GF/EP, GF/PET, Karbon/EP, fenolik keçe ve yapıştırıcı malzeme olarak PE film kullanılarak düz kalıpta, 190 °C sıcaklıkta ve 110 bar basınç altında kompozit sandviç yapılar oluşturulmuş ve bu yapıların empedans tüpünde ses yutum katsayıları ölçülerek akustik performansları birbiriyle karşılaştırılmıştır. Akustik performans test sonuçları incelendiğinde, ses yutum katsayısı (α) 1 değerine en yakın olan kompozit sandviç yapının dıştan içe doğru iki kaplama telası arasında PP/GF, PE film, taş yünü içeren malzeme kompozisyonu 1 olduğu tespit edilmiştir. Kalınlığın akustik performansa ve mukavemete etkisini incelemek üzere, en iyi akustik performansı gösteren malzeme kompozisyonu 1 ile 10 mm, 20 mm ve 30 mm kalınlıklarında üretilen numunelere akustik performans ve 3 nokta eğilme testleri uygulanmıştır. Elde edilen verilerden kalınlık arttıkça ses yutum kapasitesinin ve eğilme dayanımının arttığı tespit edilmiştir.

Copyright of Motif Academy Journal of Folklore is the property of Motif Yayincilik and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Today, although acoustic designs for different purposes are not realized in sports halls designed for sports activities, these halls are widely used for various events such as conferences and concerts. In this study; The main activity area in the Beşirli Central Tennis Court building, which was built for sports activities within the scope of the European Youth Games in Trabzon Province, was evaluated in terms of acoustics for different functional uses by computer simulation method. First of all, 3D models were prepared for the current conditions of the main sports event areas according to different audience occupancy rates. Then the models were transferred to the simulation program to evaluate the objective parameters of the sound. After obtaining the objective parameter values of the sound, 3D models of the hall were prepared again with the soundabsorbing mechanisms placed between the existing steel structural system on the ceiling plane of the hall, designed for the realization of sports, music and speech activities in the sports activity areas. The prepared 3D models were transferred to the ODEON V10 program and the simulation process was repeated. As a result of all simulations, the values of the objective parameters of the sound obtained for indoor sports activity areas were compared and evaluated with each other and the accepted optimum value ranges. [ABSTRACT FROM AUTHOR]

Copyright of Dicle University Journal of Engineering / Dicle Üniversitesi Mühendislik Dergisi is the property of Dicle Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tata bunyi ruang ibadah yang baik mendukung terciptanya suasana yang diharapkan dalam ruang dan pemahaman informasi yang disampaikan secara audial. Pengondisian bunyi dalam ruang-ruang ibadah Gereja Katolik belum populer dalam proses desain bangunan. Material akustik ruang cenderung mahal. Sebagai bangunan non-komersil, proses desain yang akurat akan membantu mendapatkan hasil sesuai standar dan meminimalkan resiko pemborosan biaya. Tulisan ini memaparkan kegiatan pengabdian masyarakat berupa pendampingan desain akustik pada empat ruang ibadah Gereja Katolik di wilayah Yogyakarta dan Jawa Tengah. Tujuan dari pendampingan ini adalah untuk menghasilkan desain yang terukur dari segi standar akustik ruang dan penggunaan biaya bahan bangunan. Selain itu juga untuk memberikan edukasi bagi para pengampu kepentingan dalam Gereja dan proses pembangunan. Metode pendampingan dan bantuan berupa studi simulasi komputer, dan pemaparan serta diskusi antara pendamping dengan Romo Paroki, serta panitia pembangunan. Hasil pendampingan telah diaplikasikan pada tiga dari empat bangunan. Pengguna ruang menunjukkan kepuasan pada hasil perencanaan dan perancangan.

Perforeli çimentolu levhalar özellikle iç mekân gürültü kontrolünde bir ses emici malzeme olarak kullanılmaktadır. Bu çalışmada, plakaların bir yüzeyinden ortalama 4 mm genişliğinde ve 6 mm derinliğinde oluklar (yarıklar) açılarak bir yüzü oluklu ve derzli form kazandırılmıştır. Çalışma kapsamında akustik performans irdelemesi için üç ayrı perforasyon oranı tasarlanmış olup sırasıyla %5.5, %8.0 ve %12.6 oranları elde edilecek şekilde levha örneklerinin diğer yüzeyinde ortalama 10 mm derinliğinde delikler açılarak perforeli test örnekleri hazırlanmıştır. Bu forma dönüştürülen levhaların ses yutma özellikleri irdelenmiştir. Delikli perforeli test örnekleri için uygulanabilirlik kesitine bağlı olarak 3 ayrı grup numune hazırlanmıştır. Bunlar; tek bileşenli yalın formda derzli perforeli çimento bağlayıcılı akustik levha (Yalın-I levhası), geotekstil katmanlı iki bileşenli derzli perforeli çimento bağlayıcılı kompozit akustik levha (Geo-II levhası) ve polietilen esaslı kauçuk katmanlı iki bileşenli derzli perforeli çimento bağlayıcılı kompozit akustik levha (PE-II levhası). Her üç grubun ses yutma özelliği referans örneği olarak test edilen düz-dolu yüzey formunda herhangi bir derz ve perfore işlemi yapılmamış elyaf takviyeli çimentolu yalın levha örneği (kontrol levhası) ile karşılaştırılmıştır. Çalışma sonuçlarına göre, derzli perforeli form kazandırılmış levha örneklerinin perforesiz düz levha formu performansları ile karşılaştırıldığında görüldüğü üzere düz levhanın absorpsiyon özelliği yüksek frekans band değişiminde artış gösterirken, derzli perforeli levhaların absorpsiyon özelliğinin ise düşük frekans bölgelerinde daha etkin absorpsiyon özelliği göstermektedir. Ayrıca, polietilen esaslı kauçuk malzemenin yalıtım katmanı olarak kullanımı, derzli ve perforeli kompozit formda çimento bağlayıcılı akustik levhaların ses azaltma karakteristiğine perforasyon oranına bağlı olarak yüksek emici ve/veya mükemmel emici birer nitelik kazandırmaktadır.

Insects in grain can cause serious problems, not only because they feed on the grains. Mass reproduction also causes additional moisture and heat due to the insects' metabolism. This leads to favourable conditions for moulds, which can cause major losses and the formation of mycotoxins. It is therefore important to detect and treat an infestation at an early stage. The "Beetle Sound Tube" system was developed as an acoustic early detection system for insects in grain, which makes it possible to detect even very low levels of infestation and inform the storekeeper by e-mail. The acoustic system remains in the grain during the storage period, and permanently records insect sounds. Challenges were encountered in the development of this acoustic monitoring system, such as analysing very quiet insect sounds in a noisy agricultural environment. In addition, the amount of data collected and the speed of analysis had to be optimised to achieve justin- time detection of insects. The acoustic tube system was developed for silos, flat stores and big bags and is therefore widely applicable. [ABSTRACT FROM AUTHOR]

Copyright of Praxis of Otorhinolaryngology / Kulak Burun Boğaz Uygulamaları is the property of Official Journal of ENT-HNS Society of Istanbul and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Seahorses are marine biota that have distinctive body characteristics that can be distinguished from other fish. Male seahorses have brood pouches. Estimation of the presence of seahorses is still very limited, an effective approach is needed to detect the presence of seahorses. The approach is carried out with an underwater acoustic approach to predict the presence of seahorses by looking at observations, namely the strength of the target. This study aims to analyze the value of Target Strength (TS) of seahorses based on size. The method used is the method of collecting experimental data. The seahorse used collected ten samples. The object placement method uses the ikat method. The TS response value was recorded using a Simrad EK-15 instrument with a frequency of 200kHz and morphometric measurements were performed. Morphometric measurements in the form of standard length measurements, seahorse head length to record acoustic signals in 3 conditions, namely females, non-pregnant males and pregnant males. Analysis of the relationship between the value of the target strength with seahorse morphometrics using statistical analysis, namely linear regression, ANOVA analysis and Tukey's follow-up test. The resulting seahorse is a species of Hippocampus. The distribution range of the resulting TS response values ranges from -58.38 dB to -67.75 dB. The result of this study is the influence of the measuring variable on the TS value formed Kuda laut merupakan biota laut yang memiliki karakteristik tubuh unik yang dapat di bedakan dari ikan lainnya. Pendugaan keberadaan kuda laut di alam masih sangat terbatas, saat ini masih menggunakan teknik visual statistik yang bersifat sampling point. Pendekatan underwater acoustic diperlukan untuk menduga keberadaan dari kuda laut di perairan, dibutukan informasi nilai pantulan akustik yang dikenal dengan target strength. Penelitian ini bertujuan untuk menganalisis nilai Target strength (TS) dari kuda laut berdasarkan ukuran. Metode yang perekaman sinyal akustik pada lingkungan alami dari habitat kuda laut. Kuda laut yang digunakan berjumlah sepuluh sampel denan metode pemeruman menggunakan thetred method. Perekaman nilai respon TS menggunakan alat scientific echosounder Simrad EK-15 frekuensi 200kHz. Pengukuran morfometrik berupa pengukuran panjang standar, panjang kepala. Data akustik dianalisis dengan perangkat lunak Sonar-5 Pro, selanjutnya analisis statistik regresi linear. Hasil penelitian menujukan hubungan nilai target strength rata-rata berkisar antara -58,38 (SD±2,93) sampai dengan -67,75 dB (SD±1,26). Hubungan TS terhadap panjang standar (PS) menunjukan hubungan positif, semakin besar ukuran kuda laut maka semakin besar pula nilai TS. Dengan formulasi TS = 20,62 log10 (PS) – 84,32 [dB], dengan koefisien determinasi sebesar 14,1 %. Sementara itu hubungan TS terhadap Panjang Kepala (PK) diformulasikan menjadi TS = 11,43 log10 (PK) – 67,72 [dB] dengan koefisien determinasi 4,1 % lebih rendah dibandingkan dengan variabel panjang standar. Hasil ini telah mempertegas bahwa ukuran kuda laut dapat mempengaruhi nilai TS.

Penelitian ini menggunakan metode simulasi analisis akustik dan visual untuk mengevaluasi kualitas ruang, serta memahami bagaimana desain ruang tertentu dapat menghadirkan kualitas multisensori yang dapat mendukung penyandang tunarungu. Simulasi analisis akustik menggunakan Ecotect untuk mengukur reverberasi dan pantulan suara. Sementara simulasi analisis visibilitas menggunakan depthmapX untuk mengukur isovist pengguna, integrasi, dan visibilitas ruang. Hasil simulasi menunjukkan bahwa ruang dengan sumber suara dari atas akan lebih baik dalam mendistribusi suara tanpa menimbulkan tingkat reverberasi ruang yang tinggi. Sumber suara berbentuk pocket dan organic enclosure dapat mengurangi tingkat reverberasi dan pantulan suara dalam ruang, meningkatkan privasi ruang sekaligus memberikan lapang pandang yang cukup luas bagi penglihatan kaum tunarungu. Hasil penelitian ini menemukan bahwa ada tiga konsep utama yang mempengaruhi kualitas akustik dan visual bagi kaum tunarungu, yaitu enclosure yang mempengaruhi tingkat privasi dan reverberasi ruang, integrasi yang menentukan visibilitas spasial dan orientasi massa atau bidang, serta material yang mempengaruhi kualitas absorpsi suara dalam ruang. This study addressed the auditorial necessity and visual potential of the deaf using acoustic and visual analysis simulation. Due to the poorly designed room acoustics, the deaf people had difficulties communicating, despite the use of hearing aids or cochlear implants. This condition often causes some distorted sound waves in hearing aids. To compensate for the deficiency in auditory abilities, the deaf people relied on their peripheral vision as a source of information for communication. However, the understanding of parameters of room geometry that are necessary to support both the acoustic and visual qualities of the deaf was limited. Based on the depthmapX and Ecotect simulations, this study discovered that the source of the sound in space should come from the top to minimise the reverberation time. Spaces in the form of pockets and with organic enclosure also minimise the reverberation time and sound reflection, achieving privacy while maintaining the potential peripheral vision of the deaf. The study also revealed that a room with acoustic and visual qualities for the deaf should incorporate three concepts, i.e., an enclosure to achieve a certain level of privacy and sound reverberation; integration of spatial visibility following the room or wall orientations; and consideration of the use of materials to absorb the different frequencies of sound.

Kappe+ – evaluation of a traditional construction method as to its performance in today's context Due to their material volume, ceiling systems are one of the biggest challenges in mulit‐storey construction on the way to climate‐friendly building. Here, the traditional masonry cap ceiling proves to be a robust, efficient alternative with innovation potential. Compared to widely used reinforced concrete flat slabs, their production requires only 50 % of the grey energy. To further investigate their application potential, six ceiling systems for office or school use were comparatively examined. Detailed life cycle assessments (LCA) were carried out for these constructions based on pre‐dimensioning. While the reinforced concrete flat ceiling has a Global Warming Potential (GWP) of 136 kgCO2e/m2, the vault ceiling achieves a value of only 64 kgCO2e/m2 in the most favourable case. In addition to assessing the energy input in manufacturing, principles of a circular economy are applied on both the material and construction side. Within a framework of practical experiments, three transformations were carried out on the historical construction: by substituting the steel girders in the system with timber, a new type of timber‐masonry hybrid system is created; with the help of digital manufacturing tools, an economical and contemporary production method is demonstrated; by optimising the bricks used, the raw ceiling is enriched with multifunctional acoustic properties. [ABSTRACT FROM AUTHOR]

Bertambahnya jumlah umat berdampak pada kebutuhan ruang ibadat yang lebih besar. Penambahan ruangan ibadat pada sayap bangunan utama menghadap ke jalan utama kota yang bising. Peningkatan volume ruang berdampak pada kualitas akustik ruang yaitu waktu dengung (RT60). Penambahan ruangan tersebut diharapkan tidak merusak identitas bangunan lama. Tujuan pengabdian adalah menghasilkan rekomendasi desain yang menyelesaikan masalah kebisingan dan kulitas akustik ruang dengan tetap mempertahankan identitas bangunan bersejarah. Analisis identitas bangunan dilakukan pada tahap awal menggunakan pemetaan fisik bangunan. Analisis perbaikan akustik bangunan menggunakan metode simulasi komputer. Hasil pemetaan fisik menunjukan bahwa bangunan Gereja Sta. Perawan Maria – Purworejo memiliki karakter arsitektur campuran antara gaya kolonial peralihan dengan kolonial moderen. Penanganan kebisingan dengan menggunakan barrier mampu menurunkan tingkat kebisingan dalam ruang maupun di teras. Penanganan kualitas bunyi dalam ruang dapat dilakukan sambil mempertahankan karakter fisik interior bangunan. Keseluruhan proses kegiatan juga menjadi sarana edukasi akademisi kepada masyarakat mengenai metode perancangan ruang ibadah yang lebih tepat sasaran dan tepat guna.

Penentuan harga jual kedelai di pasar tradisional Indonesia saat ini masih dilakukan secara manual yaitu berupa penilaian berdasarkan penampakan visual oleh tengkulak. Hal ini tentunya menyebabkan kesenjangan harga pasar kedelai. Penelitian ini bertujuan untuk menciptakan mesin sortasi untuk pendugaan kualitas biji kedelai menggunakan pendekatan sifat akustik dengan pengendali mikrokontroller arduino. Sensor akustik yang digunakan adalah sensor suara LM393. Mesin yang dibuat menggunakan prinsip angkut belt conveyor sederhana dengan tenaga penggerak motor stepper. Hasil analisis rancangan mesin menunjukkan kapasitas kerja mesin sebesar 1,431 kg/jam, torsi kerja sebesar 0,000085 Nm dan daya mesin sebesar 7,038 watt. Hasil pengujian data akustik pada kedelai dengan kadar air yang sama 10,65% dengan massa rata-rata 0,202 gram (Grade A) dan pengujian data akustik pada kedelai dengan massa rata-rata 0,165 gram (Grade B) masing-masing menghasilkan rata-rata nilai amplitudo sebesar 3671 mV dan 1993 mV. Berdasarkan uji statistik menggunakan metode Independent T-Test didapatkan nilai signifikansi sebesar 0,000 (P

Sound insulation is a kind of measure to prevent sound waves from penetrating through a material. Good sound absorbing materials are known to be lightweight, loose, and porous products. In this study, a new design approach is presented to improve the sound insulation properties of lightweight aggregate concrete blocks. Within the scope of the study, pumice, and volcanic tuff were used as lightweight aggregates in the production of concrete blocks. The acoustic properties of the masonry block specimens, in which alternative sound absorbing environments with special design are created, were analyzed on the model specimens. In particular, the effects of 3 different slit widths (12 mm, 16 mm, 20 mm wide) on the sound absorption performance of the masonry block element, in which the Helmholtz resonator form was created in its design, were investigated. The geometry of the lightweight concrete blocks is designed with three rows of gaps, and on the outer facing of the block, 4 sound slits were created at 80% of the block height to increase the sound absorption capacity, and the gaps on these sides are turned into open gaps. In addition, the technical findings of the design forms of polyester fiber felt used as reinforcement material to increase the sound absorption capacity of the block were also discussed comparatively. According to the study findings, it has been determined that as the slit width in the block design gets larger, the amount of sound received into the cavity volumes in the form of Helmholz resonator increases, and therefore it functions more as a sound absorber. In addition, with the polyethylene fiber felt reinforcement, an additional sound absorbing performance of 1.67 times is provided in the 16 mm slit block and 1.74 times in the 20 mm slit design block. [ABSTRACT FROM AUTHOR]

The article initially deals with the difficulties that can arise when sound recordings of archaeological sound objects are made in museum rooms. In order to reduce these problems as much as possible, a simple but effective, sound-reduced recording chamber has been developed. It is used in the FWF (Austrian Sciences Funds) project "Metallic Idiophones between 800 BC and 800 AD", which investigates bells, pellet bells, and jewelleries with jingles. The chamber was constructed from 8 mm thick poplar plywood panels. Its isolation consists of a double layer of mineral wool, Rockfon Facett Plano 20 mm. Measurements have shown a reduction of background noise by up to 21.4 dB SPL in various museum rooms. The transportable recording chamber is weighing only 7 kg and is therefore ideally suited for sound recordings in museums and other collections. This article describes shortly the making of the chamber and examines its noise reduction levels by means of a series of measurements. [ABSTRACT FROM AUTHOR]

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Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Müziğin iç mekan tasarımındaki yeri ve önemini araştırmak için kontrollü bir çalışma düzeneği oluşturulmuştur. Burada amaç, müziğin mekan tasarımında etkin bir öge olarak kullanılmasını sayısal olarak ölçmek ve öznel parametrelerin bu anlamda somut olarak değerlendirilmesidir. Chopin’in Marriage d’Amour adıyla bilinen Spring Waltz adlı eserinin senkronize olarak dinletilerek yürütüldüğü çalışmada sonuçlar, SPSS 21.0 istatistik programı kullanılarak değerlendirilmiştir. Pearson Ki Kare testi kullanılmıştır. Çalışmada belirlilik ve açıklık, canlılık, düzgün yayılmışlık, samimilik, sıcaklık ve denge ölçülen akustik öznel parametrelerdir. Kullanıcıların cinsiyeti ile mekan algısı -işitsel konfor değerlendirmeleri arasında bir ilişki olmadığı sonucuna varılmıştır. Müzik enstrümanı çalanlar ile mekan algısı -işitsel konfor değerlendirmeleri arasında sıcaklık parametresi için anlamlı bir ilişki bulunmuş, ölçülen diğer öznel akustik parametreler için anlamlı bir sonuç bulunmamıştır. Müzik-mekan tasarımı ve işlevle ilişkisi bağlamında katılımcılardan dinledikleri müziği bir mekanla ilişkilendirmeleri istendiğinde çıkan sonuçlar, müziğin bizi bu anlamda etkilediğini göstermiştir. Farklı geometrik formlar mekan-müzik eseri eşleştirmesi açısından değerlendirildiğinde daire formu en fazla tercih edilen form olmuştur. Kavramsal anlamda geometrik formlarla müzik eseri arasında bir ilişki bulunmaktadır. İç mimari projelerde kavramdan mekan tasarımına ulaşan, konsept üretim sürecinde bu durum etkin bir rol oynamaktadır.

Die moderne Architektur strebt nach transparenten Gebäudehüllen und insbesondere nach nachhaltigen und bauphysikalisch adäquaten Glasfassaden. Typischerweise werden Glasfassaden entworfen, um eine Vielzahl von Zielen zu erfüllen, eines davon sind die Anforderungen an den Schallschutz. Eine zuverlässige Abschätzung der Schalldämmeigenschaften beliebiger Glasaufbauten ist aufgrund der Komplexität experimenteller Tests oder numerischer Simulationen zeitaufwendig und kostenintensiv. Daher wird in dieser Arbeit ein maschineller Lern‐Ansatz zur Prädiktion der akustischen Eigenschaften beliebiger Glasaufbauten vorgestellt. SOUNDLAB AI Tool – Machine learning for the determination of the weighted sound Insulation Value. Modern architecture strives for transparent building envelopes and, in particular, for sustainable and physically adequate glass facades. Typically, glass facades are designed to meet a variety of objectives, one of which is to satisfy sound insulation requirements. Reliable estimation of the sound insulation properties of arbitrary glass assemblies is time consuming and costly due to the complexity of experimental tests or numerical simulations. Therefore, this paper presents a machine learning approach for predicting the acoustic properties of various glass setups. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Akdeniz Sanat is the property of Akdeniz University, Faculty of Fine Arts and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of e & i Elektrotechnik und Informationstechnik is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Summary Singing with the wings – instrumental sound production in birds Bird wing and tail feathers are able to produce sound in flight and during related movements. Noisy sound is produced primarily as an epiphenomenon to the movements. The sound can, however, also include tonal or harmonic structures and can gain signal value when used in social situations. In a similar way, birds can produce sounds by clattering their keratin covered beaks. For the first time, in this article, the acoustic properties of instrumental bird sounds are analyzed using sonograms. Up to now the biological meaning of instrumental sounds in birds is inferred mainly out of the situations observed. [ABSTRACT FROM AUTHOR]

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Potential of tree bark for the application as sound absorbing material Tree bark is a highly optimized natural material, which protects a tree from manifold damage at the peripheral layer. Hence, bark has some interesting technological properties, such as a low density and a good biological durability. In the wood‐industry, huge amounts of bark in pieces accrue, which are used to a low extend for high‐value applications. In this investigation, insulation panels from larch bark were produced and their inner structure was evaluated by means of CT. The sound absorption coefficient of panels with varying composition was investigated using impedance measurement and structure‐property relationships were evaluated. It was found that larch insulation panels can be applied as effective sound absorbers for frequencies higher than 500 Hz and that the frequency with the highest sound absorption can be affected changing the particle size of the panels. [ABSTRACT FROM AUTHOR]

Copyright of International Journal of Engineering Research & Development (IJERAD) is the property of International Journal of Engineering Research & Development and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)