Architectural Acoustics: Room Acoustics

Presentation by Cheol-Ho Jeong

Architectural acoustics includes room acoustical conditions and sound insulation. Human beings spend a great amount of their lifetime indoors and the quality of room acoustics and building acoustics therefore plays a crucial role in their well-being. In teaching and learning environments, both teachers and students need proper acoustical solutions, all be it in contradictory ways; Teachers need acoustical supports, e.g., reflections from the room surfaces, support to avoid voice strain, while students need sufficient speech intelligibility without so much reverberation.

http://www.act.elektro.dtu.dk/Research/Research_fields/Architectural_acoustics

Architectural acoustics

General description

Architectural acoustics includes room acoustical conditions and sound insulation. Human beings spend a great amount of their lifetime indoors and the quality of room acoustics and building acoustics therefore plays a crucial role in their well-being. In teaching and learning environments, both teachers and students need proper acoustical solutions, all be it in contradictory ways; Teachers need acoustical supports, e.g., reflections from the room surfaces, support to avoid voice strain, while students need sufficient speech intelligibility without so much reverberation.

Hospitals and large office spaces should be treated so that they have good acoustical conditions to increase the employees’ productivity: speech privacy, speech intelligibility and low background noise from both technical installations and other people’s activities. Many of us have probably experienced some trouble speaking with others in acoustically bad restaurants. An article in the Los Angeles Times in 2012 focused on the high noise levels in many eating establishments with noise being the second biggest cause of complaint after the complaints about the lousy service. Needless to say, acoustically speaking, the most critical rooms are music listening rooms, e.g., concert halls, opera houses, theaters and music studios.    

In multi-story buildings, neighbours disturb each other with many irritating sounds; music practice, children running and jumping, footsteps, vacuum cleaners and washing machines running. With good sound insulation, we can disturb each other less. The tendency in building technology is towards lightweight materials. Lightweight building structures are prone to having poor sound insulation compared to conventional heavy constructions. Consequently, the established standardized models for predicting transmission of sound in buildings are unreliable for lightweight buildings.

Research Focus

The Acoustic Technology group (ACT) focuses on room acoustical conditions in classrooms, music studios, open-plan offices and restaurants. Such rooms are of practical importance but it is often quite difficult to predict their acoustic conditions compared to large concert halls.  Another important research area is the acoustic condition in reverberation chambers, where acousticians measure sound absorption, transmission and sound power as accurately as possible. The room should ideally be diffuse, but quantification and realization of a fully diffuse sound field are quite tricky. ACT also tries to model sound absorbers and their effect on room acoustic conditions. Advanced characterization techniques of surgace absorption and scattering are also of great interest.

ACT has a long tradition of developing room acoustic simulations and various simulation models have been developed: a commercial software package ODEON and several in-house software named PBTM (Phased Beam Tracing Method), CARISM (Combination of Acoustical Radiosity and Image Source Method), PARISM (Phased Combination of Acoustical Radiosity and Image Source Method).     

Collaboration partners

Acoustic simulation: ODEON (DK)

Measurement technique: Brüel &Kjær (DK)

Absorber and class room acoustics: Ecophon (SE)

Consulting companies and Architect firms: Cowi, Ramboll, Alectia, Atkins, Gade-Mortensen, Niras, Grontmij, Lloyd Register consulting, ØDS (DK), Arup (US), Peutz (NL), Henning Larsen Architects (DK)

Academic collaboration: TU Aachen (DE), Lund university (SE), Univ. Ferrara (IT), KAIST (South Korea), NTNU (NO)

Research institute: Delta, Interacoustics, Brüel &Kjær (DK)

concerthall

reverberant room

loudspeaker

Contact

Cheol-Ho Jeong
Associate Professor
DTU Electrical Engineering
+45 45 25 39 34
http://www.act.elektro.dtu.dk/Research/Research_fields/Architectural_acoustics
26 SEPTEMBER 2017