Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Measurement and perception of sound insulation from 20 Hz between dwellings
Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics. Tyréns AB.ORCID iD: 0000-0002-8386-2292
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Population growth and urbanization are projected by the United Nations to add 2,5 billionpeople to the world’s urban population by 2050. We need to construct buildings in anunprecedented scale to meet global housing demand. Sustainable development is critical.Compared to traditional heavy constructions, lightweight wooden constructions are moreenvironmentally friendly and will play a key role in meeting future demands. However, thereare two major problems with lightweight constructions that need to be addressed: 1) Limitedlow frequency sound insulation and 2) Variations in sound insulation.Annoyance from walking sound tend to be higher in lightweight than in heavy constructionseven with the same measured sound insulation. The Swedish research program AkuLiteindicated that the correlation between measured sound insulation and annoyance wassignificantly improved by extending current evaluation methods from 50 Hz down to 20 Hz.Secondly, large variations in sound insulation between nominally identical lightweightconstructions are common, which leads to larger safety margins. By identifying and quantifyingunderlying causes, production costs can be minimized and the performance can be improved.The aim of the thesis is to develop a new evaluation method for impact sound insulation thatbetter correspond to rated annoyance, and to identify and control underlying causes forvariations in sound insulation. The thesis contains six papers.In Paper I and II, sound insulation measurements were carried out in a large number ofnominally identical rooms of two different industrially prefabricated lightweight woodenconstructions. The purpose was to assess and quantify the variations in impact and airbornesound insulation. In Paper I, 30 nominally identical apartments of a volume based system wasevaluated. The apartments on the highest floor achieved significantly better sound insulationdue to the extra weight on lower floors affecting the elastic connections between stories. InPaper II, 18 rooms of a cross-laminated timber system of plate elements were evaluated.Additionally, several potential parameters related to measurement uncertainty wereinvestigated.Paper III deals with measurement uncertainty. An empirical study of reverberation timemeasurements showed that current methods need to be improved, if sound insulationrequirements are to be extended to 20 Hz.Paper IV and V verified that the frequency range 20-50 Hz is important for walking soundannoyance, and that alternative frequency adaptation terms can improve the correlation betweenmeasured impact sound insulation and annoyance ratings. In Paper IV, the methodology was toperform extensive field measurements in apartment buildings of various construction types andto perform questionnaire surveys among the residents. In Paper V, the methodology was toevaluate annoyance based on binaural recordings of walking sound in a two-part listening test.In Paper VI, 70 measurements in a lightweight wooden system were evaluated to quantify thetotal variations in impact and airborne sound insulation from 20 and 50 Hz, respectively. It wasconcluded that the proposed metrics of impact sound insulation were primarily determined bythe impact sound level 20-40 Hz and that the measurement methods must be evaluatedthoroughly to avoid excessive safety margins.

A new evaluation method for impact sound insulation from 25 Hz, that correspond to the ratedannoyance for both heavy and lightweight constructions is proposed. By using the proposedmethod and attending the specific causes for variations, the lightweight industry will be able todevelop improved multi-story dwellings with higher perceived acoustic quality.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 2017.
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
Keyword [en]
Sound insulation, Lightweight constructions, Annoyance, Measurement uncertainty, Low frequency, Building Acoustics, Walking noise
National Category
Other Civil Engineering
Research subject
Engineering Acoustics
Identifiers
URN: urn:nbn:se:ltu:diva-62843ISBN: 978-91-7583-868-7 (print)ISBN: 978-91-7583-869-4 (electronic)OAI: oai:DiVA.org:ltu-62843DiVA: diva2:1086459
Public defence
2017-05-30, F531, Luleå Tekniska Universitet, 971 87 Luleå, 09:30 (English)
Opponent
Supervisors
Funder
Swedish Research Council Formas
Note

Forskningsfinansiärer:

Sven Tyréns Stiftelse

Formas

Available from: 2017-04-05 Created: 2017-04-03 Last updated: 2017-06-14Bibliographically approved
List of papers
1. Variations in sound insulation in nominally identical prefabricated lightweight timber constructions
Open this publication in new window or tab >>Variations in sound insulation in nominally identical prefabricated lightweight timber constructions
2010 (English)In: Building Acoustics, ISSN 1351-010X, Vol. 17, no 2, 91-103 p.Article in journal (Refereed) Published
Abstract [en]

Variations in sound insulation necessitate higher safety margins to the legal requirements, which results in higher production costs. Increased knowledge about variations leads to lowered costs and better sound quality. In-situ measurements of 30 nominally identical apartments of a lightweight timber construction were performed, to assess and quantify the variations in airborne sound reduction and impact sound pressure level. The construction is an industrially prefabricated system of complete volumes. Different sound insulation was found between floor numbers as the apartments on the highest floor achieved significantly better sound insulation. This difference was assumed to be due to the extra weight on lower floors affecting the elastic connections used to structurally connect the apartments. The variation between apartments on the same floor was therefore evaluated using the Root Mean Square Error, resulting in a standard deviation of 0,9 dB and 1,4 dB for the airborne and impact sound insulation, respectively. The measurement variance was subtracted from the total variance. The remaining, unexplainable, variation of 0,8 dB in airborne sound insulation can be attributed to workmanship.

Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-4477 (URN)10.1260/1351-010X.17.2.91 (DOI)26965a00-ba4d-11df-a707-000ea68e967b (Local ID)26965a00-ba4d-11df-a707-000ea68e967b (Archive number)26965a00-ba4d-11df-a707-000ea68e967b (OAI)
Note
Validerad; 2010; 20100907 (ricokv)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-04-03Bibliographically approved
2. On the uncertainty of building acoustic measurements: Case study of a cross-laminated timber construction
Open this publication in new window or tab >>On the uncertainty of building acoustic measurements: Case study of a cross-laminated timber construction
2012 (English)In: Applied Acoustics, ISSN 0003-682X, E-ISSN 1872-910X, Vol. 73, no 9, 904-912 p.Article in journal (Refereed) Published
Abstract [en]

If variations and uncertainty in building acoustic measurements can be controlled, construction costs can potentially be reduced since the building will not have to be acoustically over-designed. Field measurements of impact and airborne sound insulation were carried out for an industrially prefabricated cross-laminated timber (CLT) system of plate elements. The results from 18 rooms, forming three groups with respect to size, were compared to a similar study dealing with a prefabricated Volume Based Building (VBB) system. Large variations were found at frequencies below 100 Hz which is crucial for the low frequency adaptation terms connected to the weighted sound insulation indices. The measurement uncertainty was investigated by analysing the repeatability, measurement direction and the time dependence of the sound source. The variations due to the measurement procedure were found to be small compared to the total variations. It was also indicated that the variations in sound insulation are smaller with a prefabricated system compared to on-site production, since less work is required at the building site

National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-14769 (URN)10.1016/j.apacoust.2012.03.012 (DOI)e30fdd61-692b-4f18-9db8-9dcaba2ca212 (Local ID)e30fdd61-692b-4f18-9db8-9dcaba2ca212 (Archive number)e30fdd61-692b-4f18-9db8-9dcaba2ca212 (OAI)
Note
Validerad; 2012; 20120418 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-04-03Bibliographically approved
3. Uncertainty of in situ low frequency reverberation time measurements from 20 Hz: An empirical study
Open this publication in new window or tab >>Uncertainty of in situ low frequency reverberation time measurements from 20 Hz: An empirical study
2016 (English)In: Noise Control Engineering Journal, ISSN 0736-2501, E-ISSN 2168-8710, Vol. 64, no 6, 706-715 p.Article in journal (Refereed) Published
Abstract [en]

Measuring reverberation time is normally one of the steps within the procedure of determining sound insulation in dwellings where 100 or 50 Hz usually serves as the lower frequency limit. However, even lower frequencies have become a matter of interest as research in the field recently indicated that the range 20-50 Hz seems to be of great importance when it comes to the perception of impact sound in lightweight buildings. A major issue in this context is then whether it is appropriate to measure and evaluate reverberation time at such low frequencies. This paper presents an empirical study of reverberation time measurements made in two rooms using more than 100 microphone positions in each. The measurement uncertainty with respect to microphone position and combinations of positions are compared for the frequency bands from 16 to 1600 Hz. Furthermore, it is analyzed how many microphone positions are needed in order to, with a reasonable probability, end up with an uncertainty in the related standardized impact sound level insulation L′n,T within ±1 dB

National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-62674 (URN)10.3397/1/376413 (DOI)000397386900001 ()2-s2.0-85014777501 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-03-24 (andbra)

Available from: 2017-03-24 Created: 2017-03-24 Last updated: 2017-04-28Bibliographically approved
4. Correlation between sound insulation and occupants’ perception: Proposal of alternative single number rating of impact sound, part II
Open this publication in new window or tab >>Correlation between sound insulation and occupants’ perception: Proposal of alternative single number rating of impact sound, part II
2017 (English)In: Applied Acoustics, ISSN 0003-682x, Vol. 123, 143-151 p.Article in journal (Refereed) Published
Abstract [en]

A previous Swedish research project indicated the potential need for evaluating impact sound insulation from 20 Hz in buildings with lightweight constructions. This is a discrepancy compared to the commonly used frequency intervals starting from 50 or 100 Hz. The statistical significance of this groundbreaking suggestion was however not satisfactorily strong since the result was based upon a limited number of building objects.

The scope of the present paper is to secure the previous study by adding additional objects to the underlying database, thereby increasing the confidence of the results. The methodology is to perform impact sound insulation measurements in apartment buildings of various construction types and to perform questionnaire surveys among the residents. The measured sound insulation is compared to the subjective rating by the occupants in order to find the parameter giving the highest correlation with respect to frequency range and weighting.

The highest correlation was found when the impact sound insulation was evaluated from 25 Hz using a flat frequency-weighting factor. Frequencies below 50 Hz are of great importance when evaluating impact sound insulation in lightweight constructions

National Category
Fluid Mechanics and Acoustics
Research subject
Engineering Acoustics
Identifiers
urn:nbn:se:ltu:diva-62615 (URN)10.1016/j.apacoust.2017.03.014 (DOI)000399510600014 ()2-s2.0-85015798378 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-03-22 (andbra)

Available from: 2017-03-22 Created: 2017-03-22 Last updated: 2017-05-11Bibliographically approved

Open Access in DiVA

fulltext(72396 kB)177 downloads
File information
File name FULLTEXT01.pdfFile size 72396 kBChecksum SHA-512
3a561260d05e36f2d0b18e46e3c448e998c6e62d0d05cfcd437d68a8d40ce99117fb8b4a155d7bdcbf8e099b0c0bb2992f5e951cc99042288da51db8b280bf70
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Öqvist, Rikard
By organisation
Operation, Maintenance and Acoustics
Other Civil Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 177 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 1047 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf