1 Advanced Room Acoustical Measurement Techniques based on Room Impulse Responses PhD Research proposal, Eindhoven University of Technology Date: 3 rd of May, 2011 Applicant: Prof. ir. L.C.J. van Luxemburg, Eindhoven University of Technology Department Architecture, Building and Planning Unit Building Physics and Systems Relation to ongoing research: Studies on hall and stage acoustics related to recent projects Muziekcentrum Eindhoven, Casa da Musica Porto and Vredenburg Leidsche Rijn showed the need for more reliable acoustic measurement methods. Research proposal: Development of practical methods to optimise the quality of measured room impulse responses and to control the uncertainty of derived room acoustical parameters. Other applications: There are no other applications on this specific subject Keywords: Room Acoustical Measurements, Room Acoustic Parameters, Room Impulse Response
2 1 Summary 1.1 Research For decennia room acoustics has been subject to scientific research. The scientific approach started in Cambridge (US) at Harvard with the work of Wallace Clement Sabine around Since then much progress has been made. Nowadays we are quite capable of predicting and judging the acoustics of rooms, varying from living rooms to sports halls, train stations, airport terminals and hospitals to class rooms, auditoria, theatres and concert halls. For this many room acoustic parameters have been developed. We can measure and predict a great number of parameters to describe the room acoustic qualities which are referred to in the standards ISO 3382 Acoustics -- Measurement of room acoustic parameters part 1, 2 and 3. To investigate the acoustical properties of a room, one can clap his hands and listen to the response of the room. Although it may not be easy to describe accurately what you hear, this method evidently gives you an impression of whether in this room music would sound pleasant or speech would be intelligible. This principle is the basis for describing a system through one or more of its impulse responses. In room acoustics, room impulse responses are measured using a sound source and microphone. However, in practice it can be hard to achieve the right conditions and fulfill all the requirements to be able to measure the impuls response accurately and reproducably. Therefore it is important to be able to control the uncertainties in the impulse response measurement and derived room acoustical parameters. The aim of this project is to improve existing and develop new practical room acoustical measurement methods to control the measurement uncertainties in room acoustical parameters. The new or improved methods will be useful to better and unambiguously understand the influence of architectural measures in many different acoustical environments. The final results will be guidelines and tools for researchers, engineers and consultants in the field of room acoustics. 1.2 Utilization The need for relevant and reliable room acoustic descriptors is still great. The acoustics of a room is subject to strong subjective experiences, where different groups as listeners, speakers and performers use different language to express themselves. Reliable objective parameters can help to improve the understanding of what is relevant in rooms. The reliability depends to a large extent on the accuracy and reproducibility of the measured room acoustic parameters. New and improved measurement methods will help to improve the acoustics in many different types of existing and new rooms. The results of this research reliable measurement methods can be used by researchers, engineers and consultants in order to unambiguously evaluate and design acoustical applications for spaces. Results of the research may lead to the development of new or improved acoustical measurement devices and software. Knowledge transfer will take place through conferences, workshops, a master class and publications. Especially a contribution to the ISO 3382 is considered. This would be a very essential contribution to the international harmonisation in the area of room acoustics.
3 2 Composition of the group 2.1 Current group The current acoustics group of unit Building Physics and Systems, department of Architecture Building and Planning of Eindhoven University of Technology consists of: Prof. ir. L.C.J. van Luxemburg dr. ir. H.J. Martin ir. C.C.J.M. Hak Besides that, the company Level Acoustics houses in the acoustics laboratory in which among others practical and laboratory research are performed. This group consists of: ir. R.H.C. Wenmaekers ir. N.H.A.M. van Hout 2.2 Candidate The candidate for the PhD research is ir. C. (Constant) C.J.M. Hak graduated on Physics of the Built Environment (FAGO) at TU/e in 1987 on a subject on acoustics. He has been working in the building acoustics group of TU/e since then. While participating in bachelor and master education, research and consulting projects in the field of acoustics, he gained experience in fundamental and applied scientific research. The candidate teaches several courses and guides students on acoustics at TU/e, PHBO and Royal Conservatory The Hague. Also, three successful student research expeditions have been organised visiting Iceland, Sweden and Turkey resulting in a number of articles. His research efforts lead to the development of acoustical measurement devices, methods and the software program Dirac in cooperation with Acoustics Engineering (NL) and Brüel & Kjær (DK). Many new research methods have been developed and applied for consultancy projects in cooperation with TNO, DHV and Level Acoustics. Examples of projects are the concert halls Muziekgebouw Eindhoven (NL), Casa da Musica, Porto (PT) and Vredenburg Leidsche Rijn (NL).
4 Peer reviewed journal paper: [Hak & Wenmaekers 2010] Hak, C.C.J.M., Wenmaekers, R.H.C. (2010), The Impact of Sound Control Room Acoustics on the Perceived Acoustics of a Diffuse Field Recording, WSEAS TRANSACTIONS on SIGNAL PROCESSING, Issue 4, Volume 6, October 2010 Conference paper: 1 st Author [Hak & Hak 2007] [Hak & Vertegaal 2007] [Hak & Wenmaekers 2008] [Hak et al. 2008] [Hak et al. 2008] [Hak et al. 2009] [Hak & Vertegaal 2009] [Hak et al. 2009] [Hak & Bijsterbosch 2009] [Hak 2010] [Hak et al. 2010] Hak, C.C.J.M; Hak, J. (2007). Effect of Stimulus Speed Error on Measured Room Acoustic Parameters, 19th International Congress on Acoustics, ICA 2007, Madrid. Hak, C.C.J.M; Vertegaal, J.S. (2007). Mp3 Stimuli in Room Acoustic,19th International Congress on Acoustics, ICA 2007, Madrid. Hak, C.C.J.M., Wenmaekers, R.H.C. (2008). The Effect of Room Acoustics on the Perceived Acoustics of Reproduced Sound, Proceedings of Internoise 2008, Shanghai China. Hak, C.C.J.M., Hak, J., Wenmaekers, R.H.C. (2008). INR as an Estimator for the Decay Range of Room Acoustic Impulse Responses, Proceedings of the124th AES conference, Amsterdam Hak, C.C.J.M., Hout, N.H.A.M. van, Martin, H.J.(2008). Measuring Sound Insulation using Deconvolution Technique, Proceedings of the 155th ASA conference, Paris Hak, C.C.J.M., Haaren, M. van, Wenmaekers, R.H.C., Luxemburg, L.C.J. van (2009). Measuring Room Acoustic Parameters using a Head and Torso Simulator instead of an Omnidirectional Microphone, Proceedings of Internoise 2009 Ottawa, Canada. Hak, C.C.J.M., Vertegaal, H. (2009). What Exactly is Time Infinity for Acoustical Parameters, Proceedings of the 16th congress on Sound and Vibration, Krakow. Hak, C.C.J.M. et al. (2002), Bouwfysica boven de poolcirkel, Bouwfysica 12e jaargang nr 3. Hak, C.C.J.M., Bijsterbosch, K.B.A. (2009). Room Acoustic Scale Model Measurements using a Spark Train, Proceedings of the NAG-DAGA 2009, Rotterdam. Hak, C.C.J.M. (2010). The Effect of the Acoustics of Sound Control Rooms on the Perceived Acoustics of a Live Concert Hall Recording, Proceedings of 11th WSEAS International Conference on Acoustics & Music 2010, Iasi, Romania. Hak, C.C.J.M., Wenmaekers, R.H.C., Han, J., Luxemburg, L.C.J. van, Gade, A.C. (2010). Sound Strength Calibration Methods, Proceedings of ICA 2010 Sydney, Australia.
5 Co-Author [Braak et al. 2005] Braak, E.W.M. Van den, Hak, C.C.J.M., Martin, H.J., Luxemburg, L.C.J. van (2005). Influence of Stage Risers on Stage Acoustics, Proceedings Forum Acusticum 2005, Budapest, pp [Braak et al. 2009] Braak, E.W.M. Van den, Hak, C.C.J.M., Luxemburg, L.C.J. van (2009). New(Stage) Parameter for Conductor s Acoustics? - part 2: further Investigation on LQ7-40, Proceedings of Internoise 2009 Ottawa, Canada. [Bron et al. 2009] [Hoes et al. 2007] Bron-van der Jagt S.G., Hak C.C.J.M, Hornikx M.C.J. (2002). Bouwfysica boven de Poolcirkel, Meetexpeditie Studenten TU/e onder extreme Omstandigheden, Bouwfysica 16(3), pp Hoes, P., Persoon, J.W.P., Hak, C.C.J.M. (2007). Communicatie over Lange Afstand in Ondergrondse Steden Cappadocië, Bouwfysica 18-1, p [Hout et al. 2010] Hout, N.H.A.M. van, Hak, C.C.J.M., Slaat, G.E., Gerretsen, E. (2009). Measuring Sound Insulation under Extreme Conditions using Deconvolution Technique, Proceedings of the NAG-DAGA 2009, Rotterdam. [Houtsma et al. 1997] Houtsma, A.J.M., Martin, H.J., Hak, C.C.M.J., Donselaar, C.M. van (1997). Metingen aan Speciale Akoestische Maatregelen in een Concertzaal, NAGpublicatie nr.136. [Luxemburg et al. 2001] [Luxemburg et al ] [Luxemburg et al ] [Luxemburg et al. 2003] [Luxemburg et al. 2007] [Luxemburg et al. 2009] Martin, H.J (2001). Casa da Música Porto, Acoustical Experiments, Paper Dutch Acoustical Society, November , Utrecht Martin, H.J (2002). Casa da Música a New concert Hall for Port Portugal, Conference paper AES Conference June 2002, St Petersburg, Russia. Martin, H.J (2002). Casa da Música, Porto, Portugal, Proceeding Forum Acusticum, Conference September 2002, Sevilla, Spain. Martin, H.J (2003). Casa da Música, Porto, Portugal, Bouwfysica, NVBV, March Luxemburg, L.C.J. van, Hak, C.C.J.M, Kok, B.H.M, Van den Braak, E.W.M. (2007). Transparent Concert Hall Acoustics, International Congress on Acoustics ICA 2007 Madrid. Luxemburg, L.C.J. van, Heijnen, P.H., Kivits, M., Hak, C.C.J.M., (2009). Stage Acoustics Experiments on 7 Stages of Concert Halls in the Netherland, Proceedings of Internoise 2009 Ottawa, Canada. [Luxemburg et al. 2010] Luxemburg, L.C.J. van, Wenmaekers, R.H.C., Hak, C.C.J.M., Kivits, M. (2010). Stage Acoustics further Development of Parameter LQ7-40, Proceedings of Internoise 2010 Lisbon, Portugal.
6 [Martin et al ] Martin, H.J., Hak, C.C.J.M., Wely F.K. van (1989). Laboratory Sound Insulation Measurements carried out on the EC Window Pane in Different Double Test Walls, Proceedings CIB-W51-meeting. June 1989, Stuttgart, Publication 117. [Martin et al ] Martin, H.J., Hak, C.C.J.M, Huisman, W.J.J. (1989). The Acoustics of Membrane Constructions, Proceedings IASS congress 10 years progress in shell and spacial structures, Madrid, September [Pegge et al. 2009] Pegge, E., Schrijnemaekers, G.G.J., Tegelaers, G.M.T, Hak, C.C.J.M. (2007). Overdracht van Spraak via Communicatiekanalen in Cappadocië, Bouwfysica 18-1, p5-9. [Tegelaers et al. 2009] [Wenmaekers et al. 2009] [Wenmaekers & Hak 2009] [Wenmaekers et al. 2008] Tegelaers, G; Horniks, M., Hak, C.C.J.M. (2004). Akoestische Studie naar de Historische Buitenlocatie van het Parlement in IJsland, Bouwfysica Wenmaekers, R.H.C., Hout, N.H.A.M. van, Hak, C.C.J.M., Luxemburg, L.C.J. van (2009). The effect of Room Acoustics on the Measured Speech Privacy in two typical European Open Plan Offices, Proceedings of Internoise 2009 Ottawa, Canada. Wenmaekers, R.H.C., Hak, C.C.J.M., (2009). A Comparison of the Variable Acoustics of Two Foley Studio, Proceedings of the NAG-DAGA 2009, Rotterdam. Wenmaekers, R.H.C., Hak, C.C.J.M., Martin, H.J., Luxemburg, L.C.J. van (2008). Air absorption error in room acoustical modeling, Proceedings of the 155th ASA conference, Paris 2008.