@inproceedings{BloedtHoeller, author = {Bl{\"o}dt, Adrian and H{\"o}ller, Christoph}, title = {Akustische Verbesserungsmaßnahmen an Stoßstellen im Holzbau}, series = {Fortschritte der Akustik DAGA 2022: 48. Jahrestagung f{\"u}r Akustik, 21. - 24. M{\"a}rz 2022, Stuttgart und Online}, booktitle = {Fortschritte der Akustik DAGA 2022: 48. Jahrestagung f{\"u}r Akustik, 21. - 24. M{\"a}rz 2022, Stuttgart und Online}, publisher = {Deutsche Gesellschaft f{\"u}r Akustik e.V.}, address = {Berlin}, language = {de} } @techreport{HoellerZeitlerSabourin, author = {H{\"o}ller, Christoph and Zeitler, Berndt and Sabourin, Ivan}, title = {Airborne and impact sound insulation data for cold-formed steel-framed walls and floors}, publisher = {National Research Council of Canada. Construction}, doi = {10.4224/23002823}, abstract = {This report presents the results of an extensive series of direct sound insulation tests of cold-formed steel-framed walls and floors. The direct airborne sound insulation of 30 walls with cold-formed steel framing was measured in accordance with ASTM E90-09. The walls had steel studs with a depth of 92 mm (3-5/8") or 152 mm (6"), and with a steel thickness of 1.09 mm (0.043") or 1.37 mm (0.054"). Other parameters that were investigated included the number of layers and thickness of gypsum board, the cavity insulation, the stud spacing, and the use of resilient channels. The test results for some non-standard wall configurations that were tested for research purposes (e.g. for walls with gypsum board on one side only) are also included in this report. The direct airborne and impact sound insulation of 17 floors with cold-formed steel framing was measured in accordance with ASTM E90-09 and ASTM E492-09, respectively. The floors had steel joists with a depth of 254 mm (10") or 317 mm (12.5"), and with a steel thickness of 1.37 mm (0.054"). The top surface of the floor/ceiling assemblies was composed of a corrugated steel deck with poured gypsum concrete, while the bottom surface was composed of a gypsum board ceiling on resilient channels. The influence of the joist depth and the number of layers and thickness of the ceiling gypsum board was investigated, as well as the influence of several floor coverings (e.g. laminate or carpet). The report presents the detailed specimen descriptions and specimen properties and the results from the standardized tests according to ASTM E90-09 and ASTM E492-09. Brief analyses of the parameters affecting the sound insulation of the steel-framed assemblies are provided. The tests presented in this report were part of a large research study that also included an investigation into the flanking sound transmission in cold-formed steel-framed buildings. The results of that study are described in the NRC Research Report RR-337, "Apparent Sound Insulation in Cold-Formed Steel-Framed Buildings" [1]. The NRC Research Report RR-337 also includes some of the airborne sound insulation results presented here, albeit without listing the detailed specimen descriptions and specimen properties that are provided in this report.}, language = {en} } @article{HoellerGibbs, author = {H{\"o}ller, Christoph and Gibbs, Barry M.}, title = {Source substitution method for obtaining the power transmission from vibrating sources in buildings}, series = {Applied Acoustics}, volume = {141}, journal = {Applied Acoustics}, publisher = {Elsevier}, doi = {10.1016/j.apacoust.2018.07.014}, pages = {240 -- 249}, abstract = {This paper describes a method analogous to the airborne sound source substitution method, to estimate the vibrational power injected by a structure-borne sound source into the supporting building element. The injected vibrational power is required for prediction of the structure-borne sound pressure from vibrating equipment in buildings. The paper focuses on high-mobility sources connected to low-mobility receivers, a situation which is commonly encountered in heavyweight construction. The mobility mismatch simplifies the transformation of laboratory measurement data to prediction of transmitted power in-situ. Three case studies were performed. In the first study, the power injected by a simple test source into a resiliently supported aluminium plate was determined using direct and indirect methods. Source substitution was investigated with different calibration options: steady-state excitation, transient excitation, and spatial averaging. The source power could be determined within 4 dB, compared with direct measurements of the injected power. In the second study, the power injected by a second source into a concrete transmission suite floor was determined. The third study was of a combined heating and power unit on a masonry wall. In this study, a reference sound pressure level in a receiver room was calculated and compared with a criterion curve for the assessment of low-frequency noise complaints. The case studies demonstrate that structure-borne sound source substitution is a promising development of the reception plate method. While the latter can be used if a free reception plate is available, the former circumvents problems of determining the transmitted power into coupled plates and therefore has application to real building conditions. The use of the instrumented hammer for the calibration and the use of spatial averaging significantly simplify the method.}, language = {en} } @article{LievensHoellerDietrichetal., author = {Lievens, Matthias and H{\"o}ller, Christoph and Dietrich, Pascal and Vorl{\"a}nder, Michael}, title = {Predicting the Interaction Between Structure-Borne Sound Sources and Receiver Structures from Independently Measured Quantities}, series = {Acta Acustica united with Acustica}, volume = {100}, journal = {Acta Acustica united with Acustica}, number = {1}, publisher = {European Acoustics Association (EAA)}, doi = {10.3813/AAA.918688}, pages = {79 -- 92}, abstract = {Structure-borne sound sources are usually characterised by their source activity and source mobility. By combining this data with the mobility of receiver structures it is theoretically possible to predict the sound pressure level in a building. In a case study of a washing machine on a wooden joist floor this prediction process was investigated. The prediction was based on the normal force component only. The contact area at the feet of the washing machine was made as small as possible to avoid the influence of moments while the in-plane components were assumed negligible. These conditions proved to allow for accurate predictions in the coupled state in a previous publication [1]. The results show that the prediction from independently measured normal source and receiver quantities yields large errors below 125 Hz as a consequence of the above assumption. Between 125 and 900 Hz the error of the prediction is within ± 5 dB. The case study further investigated two assumptions frequently encountered in practice: low and high-mobility sources and no cross-coupling between the feet}, language = {en} } @techreport{HoellerMahnQuirtetal., author = {H{\"o}ller, Christoph and Mahn, Jeffrey and Quirt, David and Schoenwald, Stefan and Zeitler, Berndt}, title = {Apparent sound insulation in cross-laminated timber buildings}, publisher = {National Research Council of Canada. Construction}, doi = {10.4224/23002009}, pages = {116}, abstract = {This Report presents the results from experimental studies of airborne sound transmission, together with an explanation of calculation procedures to predict the apparent airborne sound transmission between adjacent spaces in a building whose construction is based on cross-laminated timber (CLT) panels. There are several types of CLT constructions which are commercially available in Canada, but this study only focused on CLT panels that have adhesive between the faces of the timber elements in adjacent layers, but no adhesive bonding the adjacent timber elements within a given layer. There were noticeable gaps (up to 3 mm wide) between some of the timber elements comprising each layer of the CLT assembly. These CLT panels could be called "Face-Laminated CLT Panels" but are simply referred to as CLT panels in this Report. Another form of CLT panels has adhesive between the faces of the timber elements in adjacent layers as well as adhesive to bond the adjacent timber elements within a given layer. These are referred to as "Fully-Bonded CLT Panels" in this Report. Because fully-bonded CLT panels have different properties than face-laminated CLT panels, the sound transmission data and predictions in this Report do not apply to fully-bonded CLT panels.}, language = {en} } @article{HoellerGibbs, author = {H{\"o}ller, Christoph and Gibbs, Barry M.}, title = {Indirect determination of the mobility of structure-borne sound sources}, series = {Journal of Sound and Vibration}, volume = {344}, journal = {Journal of Sound and Vibration}, publisher = {Elsevier}, doi = {10.1016/j.jsv.2015.01.011}, pages = {38 -- 58}, abstract = {Methods are considered for the indirect determination of the mobility of structure-borne sound sources. Instead of performing measurements on the source in the free state, the source mobility is obtained from measurements made in-situ. This approach is beneficial if the source is difficult to suspend, or if it contains nonlinear structural elements. Two formulations for an indirect source mobility are derived theoretically. The first requires measurement of velocities at or near to the contact points. The second involves measurement of remote velocities only. Neither of the methods requires excitation at the contacts in the coupled state. Numerical simulations of coupled beams are used to validate the two methods and investigate their accuracy and reliability with respect to typical measurement errors, such as background noise and inaccuracies in sensor positioning. It is found that these can have a significant effect on the methods considered. Several experimental case studies with single-contact and multi-contact sources are performed. The results confirm the validity of the two methods in principle, but highlight their sensitivity to experimental errors. In a representative case study with a fan unit, average errors range between ±5 dB and ±10 dB, with occasional errors of up to 30 dB.}, language = {de} } @article{HoellerGibbs, author = {H{\"o}ller, Christoph and Gibbs, Barry M.}, title = {Inverse Method to Obtain Blocked Forces of Vibrating Sound Sources in Buildings}, series = {Acta Acustica united with Acustica}, volume = {103}, journal = {Acta Acustica united with Acustica}, number = {4}, publisher = {ingenta}, doi = {10.3813/AAA.919092}, pages = {639 -- 649}, abstract = {Vibrating sources, such as building service equipment, are major contributors to noise in buildings. In order to predict and subsequently reduce the sound pressure levels generated by these devices, it is necessary to first predict the total vibrational power injected by them into the supporting building structure. Whilst simplified methods are available for the calculation of the total power through all contacts, it would be beneficial to have more detailed knowledge of the dominant contact powers. For sources on low-mobility building elements, the contact powers are determined by the blocked force, along with the real part of the receiver mobility at each contact. This paper describes a novel inverse method to obtain the blocked forces at each contact. The method employs an instrumented reception plate, which is numerically modelled to allow optimum accelerometer positions to be selected, for any source and any location. The underlying theory and measurement procedure are described, and experimental validations are presented.}, language = {en} } @techreport{MahnQuirtHoelleretal., author = {Mahn, Jeffrey and Quirt, David and H{\"o}ller, Christoph and M{\"u}ller-Trapet, Markus}, title = {Addendum to RR-335: sound transmission through Nail-Laminated Timber (NLT) assemblies}, publisher = {National Research Council of Canada. Construction}, doi = {10.4224/40000417}, abstract = {This report is published as an addendum to NRC Research Report RR-335 "Apparent Sound Insulation in Cross-Laminated Timber Buildings." It is intended that this addendum will be merged with RR-335 in the future as a report for predicting the sound insulation in buildings using mass-timber constructions including NLT assemblies. This report presents the results from experimental studies of airborne sound transmission through assemblies of nail-laminated timber (NLT) with various linings. To put the data presented in this report in the proper context, this report begins with a brief explanation of calculation procedures to predict the apparent sound transmission class (ASTC) between adjacent spaces in a building whose structure is a combination of mass-timber assemblies such as nail-laminated timber (NLT) or cross-laminated timber (CLT) panels.}, language = {en} } @techreport{HoellerMuellerTrapetKingetal., author = {H{\"o}ller, Christoph and M{\"u}ller-Trapet, Markus and King, Frances and Bradley, John}, title = {Evaluation of the communication performance of the C4 chemical, biological, radiological and nuclear mask}, doi = {10.4224/23003981}, abstract = {The Canadian Armed Forces (CAF) are using chemical, biological, radiological and nuclear (CBRN) general service respirators (GSRs) to defend against CBRN threats and hazards to protect personnel and ensure that they can safely and successfully carry out missions. The CBRN GSR currently in use by the CAF is the C4 respirator. The National Research Council of Canada assessed the communication performance of the C4 respirator. This report presents the results of the performance test. The method for assessing the communication performance used in this study was the NIOSH standard test procedure TEB-CBRN-APR-STP-0313 [1]. Other methods exist to evaluate the communication performance of respirators, but historically the NIOSH standard test procedure has been used. This report details the implementation and results of the tests conducted at the National Research Council of Canada, following the NIOSH standard test procedure.}, language = {en} } @techreport{HoellerQuirtZeitleretal., author = {H{\"o}ller, Christoph and Quirt, David and Zeitler, Berndt and Sabourin, Ivan}, title = {Apparent sound insulation in cold-formed steel-framed buildings}, publisher = {National Research Council of Canada. Construction}, doi = {10.4224/23001843}, abstract = {This Report presents the results from substantial experimental studies of sound transmission, together with an explanation of calculation procedures to predict the sound transmission between adjacent spaces in a building whose walls and floors have cold-formed steel (CFS) framing. This first edition contains mainly data for loadbearing steel framing formed from sheet steel with thickness from 1.37 mm (16 gauge) to 0.94 mm (20 gauge). Non-loadbearing CFS studs formed from thinner steel (nominally 0.54 mm) are also commonly used but these are not included in the data tables for sound transmission through wall assemblies in this Report.}, language = {en} } @phdthesis{Hoeller, author = {H{\"o}ller, Christoph}, title = {Indirect methods of obtaining activity and mobility of structure-borne sound sources}, publisher = {University of Liverpool}, address = {Liverpool}, abstract = {The work reported in this thesis focuses on the development of indirect methods for the experimental determination of important source parameters for structure-borne sound source characterization. In the first part of the thesis, matrix inversion methods for the determination of blocked forces are investigated. A simplified measurement procedure is proposed which offers a solution to the two major challenges to these methods, namely the acquisition of the FRF matrix and the problems associated with matrix inversion. The proposed procedure involves a free, low-mobility receiver plate which is modelled numerically. Calculated FRFs are used together with measured velocity responses to inversely determine the blocked forces. It is found that while the method has great potential in principle, in practice the accurate modelling of the receiver plate is of critical importance. In the second part of the thesis, three formulations are considered for the indirect determination of source mobility. Instead of performing measurements on the source in the free state, the source mobility is obtained from measurements made in-situ. This approach is beneficial if the source is difficult to suspend, or if it contains non-linear structural elements. The three formulations are validated numerically and experimentally. It is found that the methods can quantify source mobilities of single-contact and multi-contact sources from in-situ measurements. However, typical measurement errors, such as background noise or inaccuracies in sensor positioning, can significantly reduce the accuracy and reliability of the methods. In the final part of the thesis, the reception plate method for the determination of the power injected by a high-mobility source into a low-mobility receiver is reviewed, and a source substitution method proposed as a development. The substitution method circumvents problems that may arise when the reception plate method is applied to coupled walls and floors. A special focus of investigation is on the calibration of the receiver structure. It is found that the calibration can be performed with shaker or hammer, and that an average calibration factor may be used. The source substitution method thus offers a potential alternative to the reception plate method, for application with coupled plates.}, language = {en} } @article{BauhuberMikrievskijLechner, author = {Bauhuber, Michael and Mikrievskij, Andreas and Lechner, Alfred}, title = {Isotropic wet chemical etching of deep channels with optical surface quality in silicon with HNA based etching solutions}, series = {Materials Science in Semiconductor Processing}, volume = {16}, journal = {Materials Science in Semiconductor Processing}, number = {6}, publisher = {Elsevier}, doi = {10.1016/j.mssp.2013.05.017}, pages = {1428 -- 1433}, abstract = {Online trace analysis based on UV/Vis spectroscopy requires long detection paths. Therefore an isotropic wet etch process in silicon is developed to fabricate a 300 µm deep channel with low channel wall roughness for desired light guidance application. Four etchant compositions were compared in terms of etching rate, surface roughness and selectivity in a beaker process. The best fitting mixture was selected. To further increase the surface quality (bubble issue) a spin etcher tool is used for producing the channels. The dependence of homogeneity and defect density on media flux, and rotation velocity was investigated. Results show that high rotation velocity and high media flux lead to great defects in the channel wall. Through rotation of the wafer during etching, the etching rate of silicon rises compared to the beaker process due to the rapid removal of etch products and simultaneous supply of fresh etchant. After 38 min of etching, 300 µm deep semi-circular channels with high optical quality (Rq=10 nm±2 nm) over 3 m were produced.}, language = {de} } @inproceedings{HoellerZeitler, author = {H{\"o}ller, Christoph and Zeitler, Berndt}, title = {Laboratory study on flanking sound transmission in cold-formed steel-framed constructions}, series = {Towards a quieter future : 45th International Congress and Exposition on Noise Control Engineering (Internoise 2016) : Hamburg, Germany, 21-24 August 2016, Vol 8}, booktitle = {Towards a quieter future : 45th International Congress and Exposition on Noise Control Engineering (Internoise 2016) : Hamburg, Germany, 21-24 August 2016, Vol 8}, publisher = {Curran Associates Inc.}, pages = {6238 -- 6249}, abstract = {In a recent study at the National Research Council Canada, the sound transmission in cold-formed steel-framed constructions was investigated. The results of direct sound insulation tests of wall and floor assemblies were reported at EURONOISE 2015 and INTERNOISE 2015. This paper focuses on flanking sound transmission in cold-formed steel-framed constructions. A representative full-scale mock-up specimen was constructed in NRC's 8-room flanking transmission facility. The specimen consists of four loadbearing walls with 152 mm deep steel studs, four non-loadbearing walls with 92mm deep steel studs, and four floor-ceiling assemblies consisting of steel joists and a composite steel deck with gypsum concrete. Measurements were conducted according to the indirect method described in ISO 10848. The individual flanking paths were measured by a sequence of transmission loss measurements in which other transmission paths were suppressed by shielding. For the bare specimen without linings, the sound transmission for horizontally adjacent rooms with continuous subfloors is dominated by the floor-floor flanking paths. Floor coverings or floor toppings are needed to meet the requirements in the National Building Code of Canada. This paper presents details of the measurements, highlights some of the results and discusses implications.}, language = {en} }