lnu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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
Incremental use of FFT as a solution for low BT-product reverberation time measurements
RISE, Sweden.
Linnaeus University, Faculty of Technology, Department of Mechanical Engineering. (Strukturdynamik)ORCID iD: 0000-0002-4404-5708
RISE, Sweden.
Turku University of Applied Science, Finland.
2023 (English)In: Applied Acoustics, ISSN 0003-682X, E-ISSN 1872-910X, Vol. 203, article id 109191Article in journal (Refereed) Published
Sustainable development
SDG 11: Make cities and human settlements inclusive, safe, resilient, and sustainable
Abstract [en]

The limitations in performance of band-pass filters to accurately process rapid decaying signals in lower frequency bands is an obstacle for some measurements within building acoustics. For instance, it would be beneficial to be able to accurately measure reverberation times down to the 20 Hz one-third octave band for impact sound in timber buildings.

Here, it is tested whether calculations with FFT with small incremental steps may be a way to achieve discrete frequency time signals with faster performance than traditional band-pass filters. The tests show that incremental FFT gives accurate estimations of the reverberation time corresponding down to 0.1 seconds at 20 Hz with a spectral resolution of 2 Hz. Using the one-third octave limits it is possible to form approximate one-third octave band results. It is seen that accurate estimations of reverberation time are achievable for BT ≥ 0.5 (T = 0.1 seconds for the 20 Hz one-third octave band) and possibly even lower, if the dynamic range in the interrupted noise signal is sufficient. The higher one-third octave results show to work as well. A disadvantage with the method is that during short reverberation times (0.1 seconds) there is a severe spectral leakage to the side bands. Also, the method requires higher dynamic range decay signals compared to band-pass filtered signals. If a one-third octave resolution is requested, a dynamic range of 50 dB or greater is preferable. With a coarse resolution of e.g., 10 Hz and having no averaging into one-third octave bands, it is possible to measure short reverberation times (0.1 s) with signals having close to the same dynamic range used in classical band-pass filtered reverberation time measurements.

Place, publisher, year, edition, pages
Elsevier, 2023. Vol. 203, article id 109191
Keywords [en]
Reverberation time, Low frequency, FFT
National Category
Building Technologies
Research subject
Technology (byts ev till Engineering), Civil engineering
Identifiers
URN: urn:nbn:se:lnu:diva-118074DOI: 10.1016/j.apacoust.2022.109191ISI: 000921541900001Scopus ID: 2-s2.0-85145964362OAI: oai:DiVA.org:lnu-118074DiVA, id: diva2:1722348
Projects
Tandem Forest Value
Funder
The Royal Swedish Academy of Agriculture and Forestry (KSLA), TF2019-0049Available from: 2022-12-28 Created: 2022-12-28 Last updated: 2023-03-16Bibliographically approved

Open Access in DiVA

fulltext(2982 kB)234 downloads
File information
File name FULLTEXT01.pdfFile size 2982 kBChecksum SHA-512
859ba56b1af32dc7bb2906496b40ce8672da53dec366e13b383adad5c7bb5f44943201eb3a775eef4ce38058e25dd7a40e61889e8acbb1d58d3cdaf5ddca0115
Type fulltextMimetype application/pdf

Other links

Publisher's full textScopus

Authority records

Linderholt, Andreas

Search in DiVA

By author/editor
Linderholt, Andreas
By organisation
Department of Mechanical Engineering
In the same journal
Applied Acoustics
Building Technologies

Search outside of DiVA

GoogleGoogle Scholar
Total: 234 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

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 380 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • 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