|SOUND IN BUILDING AND ENVIRONMENT||VTAF01|
The aim of the course is to give the students knowledge in the foundations of sound and its effect on human, applied to problems with noise in buildings and environment.
Knowledge and understanding
For a passing grade the student must
· Be able to explain how sound is created, spread and recieved by human, and the effect of sound on health and wellbeing.
· Be able to explain different recomended maximum values and regulations against noise, and be able to explain different measures that can be taken to reduce the impact of noise in enviroment.
· Be able to explain how sound is transmitted and reduced in buildnings in the cases of direct transmission and flanking transmissions.
· Be able to explain different types of acoustic measurement methods in rooms, between rooms, and in environment.
Skills and abilities
For a passing grade the student must
· Be able to perform a measurement and calculation of the reverbation time in a room, as well as propose measures to attain desired acoustical properties.
· Be able to perform a measurement of the of the sound insulation in a wall and step sound insulation in a floor according to standardised model, as well as vibrations in and between structural elements.
· Be able to perform calculations of reverbation time, sound insulation and impact sound level for a given room and building.
· Be able to plan, execute and analyse measurements of sound levels from traffic noise.
· Be able to perform calculations of sound levels at different traffic situations using commersial software.
· Be able to interpret and analyse different measurement signals and frequency spectra.
· Be able to work practically with acoustic measurement equipment.
· Be able to present a solution to an acostic problem in a technical report.
The course begins with an introduction to acoustics and an exposition of different aspects of sound:
· Sound sources description of different sources of sound and principles of how sound is generated.
· Description physical and mathematical description of sound, sound pressure, sound level, frequency, wavelength, sound speed, frequency spectrum with fouriertransform, octave- and third octaveband, different filters and weighing.
· Spread spread of sound in different media, diffraction, interference, a general description of sound insulation and vibration.
· Measurement sound measuremenet using microphone and ear.
· Subjecitve measures (psycho acoustics) models for how different sounds is percieved by human.
After that follows an exposition of noise from traffic.
· Recomended maximum values and regulations of noise.
· Effect on human.
· Spread of noice and noise reducing measures.
Then the more advanced sections of buildning acoustics.
· Room acoustics Sound absorption and different absorbents, eigenvalue analysis, reverbation time and room acoustic planing.
· Sound insulation Insulation in single and double wall, vibration insulation of construction elements, impact sound insulation.
· Structure borne tomljud Vibrations transmitted between construction elements, flanking transmission, transmission of sound from floor to wall and continuing. Impact sounds.
The course also contains a section on measurement methodologics in acoustics, which is treated in two laborations.
· A presentation of equipment and measurement methods for sound and vibrations.
· Measurement of sound insulation, sound absorption and transmission.
The course is also containing one of three following alternative project tasks consisting on a field measurement with a modellation that is to be presented in a written report, and by an oral presentation.
· Vibration measurmenet on flooring with corresponding simulation of transmission using simulation software.
· Measurement of noise level in traffic situation and simulation of corresponding noise level using commercial software.
· Estimation of reverbation time in an existing room, as well as calculation of absorption area and proposition of measures to be taken.
Bard, D; Stålne, K Kompendium i Akustik (2009)
Laborationshandledningar: Ljudisolering och Absorption