### Abstract

Original language | English |
---|---|

Place of Publication | Espoo |

Publisher | VTT Technical Research Centre of Finland |

Number of pages | 42 |

ISBN (Print) | 951-38-4227-4 |

Publication status | Published - 1992 |

MoE publication type | Not Eligible |

### Publication series

Series | VTT Publications |
---|---|

Number | 109 |

ISSN | 1235-0621 |

### Fingerprint

### Keywords

- buildings
- acoustics
- sound waves
- noise reduction
- acoustic measurement
- estimating
- utilization
- sound pressure
- calculations
- methods
- spectra
- indexes (ratios)
- windows
- doors
- evaluation
- Spectrumindex

### Cite this

*Study on the possibilities to apply spectrumindex*. Espoo: VTT Technical Research Centre of Finland. VTT Publications, No. 109

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*Study on the possibilities to apply spectrumindex*. VTT Publications, no. 109, VTT Technical Research Centre of Finland, Espoo.

**Study on the possibilities to apply spectrumindex.** / Parmanen, Juhani; Sysiö, Pauli.

Research output: Book/Report › Report

TY - BOOK

T1 - Study on the possibilities to apply spectrumindex

AU - Parmanen, Juhani

AU - Sysiö, Pauli

N1 - Project code: LVI1464

PY - 1992

Y1 - 1992

N2 - Possibilities to apply spectrumindex in building acoustics are studied. As usually, spectrumindex refers to the difference of two sound pressure levels caused by the same sound field and measured using two separate frequency weightings (A- and C-weighting). The purpose of the study is to develope a simple method in which one can apply the spectrumindex to evaluate the traffic noise reduction indices existing already in a NORDTEST-method. Some difficulties in that method, i.e. its definitions, used spectra and the extensive datamaterial, are discussed too. Further, the spectrumindex principle has been applied to a testmaterial of 20 different windows. Two alternatives have been used as basic sound reduction indices, one for pink noise and the other for a traffic noise spectrum modified from the spectrum given in the French standard NF S 31-051. Three different equations were tested in estimating the reduction index for other spectra for which only the spectrumindex is known. Finally, the equation including the best realizable sound insulation curves has been chosen as the most feasible estimation method. It has been shown, that by accepting some little limitations concerning the noise spectra and magnitude of spectrumindex, one can get very reliable estimation results. In general, the deviation will be at the most 1 dB from the correct value calculated in accordance with the NORDTEST-method. This may be seen important also therefore, that instead of the 32 different numbers needed traditionally, here only three are necessary in calculating the noise reduction index. The study has been finalized by using a Greek material consisting of 11 exterior doors and one single pane window.

AB - Possibilities to apply spectrumindex in building acoustics are studied. As usually, spectrumindex refers to the difference of two sound pressure levels caused by the same sound field and measured using two separate frequency weightings (A- and C-weighting). The purpose of the study is to develope a simple method in which one can apply the spectrumindex to evaluate the traffic noise reduction indices existing already in a NORDTEST-method. Some difficulties in that method, i.e. its definitions, used spectra and the extensive datamaterial, are discussed too. Further, the spectrumindex principle has been applied to a testmaterial of 20 different windows. Two alternatives have been used as basic sound reduction indices, one for pink noise and the other for a traffic noise spectrum modified from the spectrum given in the French standard NF S 31-051. Three different equations were tested in estimating the reduction index for other spectra for which only the spectrumindex is known. Finally, the equation including the best realizable sound insulation curves has been chosen as the most feasible estimation method. It has been shown, that by accepting some little limitations concerning the noise spectra and magnitude of spectrumindex, one can get very reliable estimation results. In general, the deviation will be at the most 1 dB from the correct value calculated in accordance with the NORDTEST-method. This may be seen important also therefore, that instead of the 32 different numbers needed traditionally, here only three are necessary in calculating the noise reduction index. The study has been finalized by using a Greek material consisting of 11 exterior doors and one single pane window.

KW - buildings

KW - acoustics

KW - sound waves

KW - noise reduction

KW - acoustic measurement

KW - estimating

KW - utilization

KW - sound pressure

KW - calculations

KW - methods

KW - spectra

KW - indexes (ratios)

KW - windows

KW - doors

KW - evaluation

KW - Spectrumindex

M3 - Report

SN - 951-38-4227-4

T3 - VTT Publications

BT - Study on the possibilities to apply spectrumindex

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -