Measuring Room Impulse Responses: Impact of the Decay Range on Derived Room Acoustic Parameters

Hak, Ccjm Constant; Wenmaekers, Rhc Remy; Luxemburg, van Lcj Renz

doi:10.3813/aaa.918574

Cited by 43 publications

(28 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The measured IRs were obtained by using a deconvolution technique with an exponential swept sine as the measurement signal. The quality of the obtained IRs was high enough to be able to extract the targeted acoustical parameters (Hak, Wenmaekers, and van Luxemburg, 2012). The used equipment has been tested in a reverberation room of the Eindhoven University of Technology (volume 100 m 3 ).…”

Section: Measurement Methodsmentioning

confidence: 99%

Acoustic modelling of sports halls, two case studies

Hornikx

Hak

Wenmaekers

2014

Journal of Building Performance Simulation

View full text Add to dashboard Cite

To achieve a preferable sound field in traditionally shoebox-shaped sports halls, the sound absorbing material is often applied in the upper part of the hall. The applicability of predicting the acoustics of sports halls by three different acoustic calculation methods is investigated: a diffuse field method, a geometrical acoustics method and a full wave-based method. The predicted reverberation time and sound pressure level are compared to measured data for two sports halls in the low frequency range up to the 630 Hz 1 3 octave band. From the three methods, results from the wave-based method agree best with the measured results. Results indicate the importance of the chosen material properties in the prediction methods used. Sound pressure levels resulting from the diffuse field method are comparable with results from the other prediction methods, but the reverberation time prediction is not reliable using this method.

show abstract

Section: Measurement Methodsmentioning

confidence: 99%

Acoustic modelling of sports halls, two case studies

Hornikx

Hak

Wenmaekers

2014

Journal of Building Performance Simulation

View full text Add to dashboard Cite

show abstract

“…Impulse responses (IRs) were obtained through the deconvolution of a 9 s linear sine sweep used as signal. A linear rather than exponential sweep was preferred in order to improve S/N ratio in the high frequency range and allow proper compensation of air absorption effects (Hak et al 2012).…”

Section: Measurements Of Room Acoustic Parametersmentioning

confidence: 99%

Room acoustic modelling of textile materials hung freely in space: from the reverberation chamber to ancient churches

Alonso

Martellotta

2015

Journal of Building Performance Simulation

View full text Add to dashboard Cite

The aim of this study is to investigate how sound absorbing materials like curtains should be modelled in geometrical acoustic (GA) software when hung freely in space. The use of these tools is widespread today. Whatever the scope of the simulation, dealing with textile materials can be particularly challenging as they both absorb and transmit sound, and absorption is dependent on distance of the walls. Therefore, care must be taken to enter properly validated data. Absorption coefficients found in the literature are measured with samples close to wall, and are not suitable when materials are hung freely. The effects of material placement on both absorption and transmission coefficients were therefore investigated using scaled-down physical models of a reverberant chamber and a church. Subsequently, GA models of both spaces were used to demonstrate that simulated results are reliable assuming that absorption and transmission coefficients are correctly determined.

show abstract

“…For G the 10 meter distance wasc hosen by Barron and Lee for reasons of convenience because this choice will often result in measured values of the sound level L p close to the reference value L p,10m and hence values of G close to 0dB [7]. G can either be determined using stationary noise or using impulse responses [1], where the sound pressure exposure level L pE is determined (upto the time point that the energy decay,o rI mpulse to Noise Ratio (INR) [ 8], is 30 dB or lower). The single number rating for G is calculated from the average of the 500 and 1000 Hz octave band, defined by ISO 3382-1 as G M ,and the Just Noticeable Difference (JND) is 1dB.…”

Section: Room Acoustic Parameters and Sound Powermentioning

confidence: 99%

The Sound Power as a Reference for Sound Strength (G), Speech Level (L) and Support (ST): Uncertainty of Laboratory and In-Situ Calibration

Wenmaekers

Hak

2015

Acta Acustica united with Acustica

Self Cite

View full text Add to dashboard Cite

Some room acoustic parameters require the sound power of the sound source. The Sound Strength G uses the free field sound pressure levelat10meters distance as areference value. Speech intelligibility parameters likethe Aweighted Speech Level, L p,A,S,4m ,and the Speech Transmission Index, STI, can require an absolute source level defined at 1mdistance from the sound source. The Early and Late Support parameters use the sound levelat1m distance as areference level. In this paper,all proposed methods to obtain the sound power levelfor room acoustic applications are investigated, using various omnidirectional sound sources with adodecahedron shape containing 12 loudspeakers. It is shown that, for octave bands 250 to 8,000 Hz, the sound power can be determined with 0.8 dB uncertainty when using precision methods (diffuse field, intensity or free field). Alternative laboratory calibration methods, that only measure in as ingle plane of the sound source, showd eviations up to 2dBp er octave band. Different stepwise rotational averages, used in such as ingle plane free field method, have been investigated. It can be concluded, that the uncertainty is significantly reduced only when using 12.5 degree steps (ISO 3382-1)a nd when using equal-angular rotations with 5o r7s teps. Furthermore, the uncertainty of insitu calibration has been investigated. Acomparison of results from different researchers shows that acorrection factor should be applied to correct the in-situ calibration for its deviation from the laboratory calibration. Foreach calibration method the uncertainty is presented. Results showthat some methods might be sufficiently accurate to be able to measure single number ratings for G, ST, L p,A,S,4m and STI with an uncertainty in the order of magnitude of 1JND, provided that no other measurement errors are introduced in the measurement chain. PACS no. 43.55.Br,43.55.Mc, 43.58.Vb, 43.58.Fm Received07July 2014, accepted 05 August 2015.sured in the free field at ac ertain distance. Also, when determining speech intelligibility parameters, like STI,the signal to noise ratio is determined based on aratio of absolute sound pressures (following ISO 16268-16 [2], only if background noise is taken into account, and following ISO 3382-3 [3], for all measurements in open plan offices). Following ISO 3382, all of these room acoustic parameters should be determined using an omnidirectional sound source. Ac ertain deviation from omnidirectionality is allowed and the deviation limits are giveninthe standard.Lundeby et al.[4] asked 8different teams to determine room acoustic parameters for 10 source-receiverc ombinations in a1,800 m 3 auditorium. He found astandard deviation for the levelp arameter Sound Strength G of only 0.2 to 0.3 dB for the octave bands 125, 1,000 and 4,000 Hz. These results would suggest that G can be measured with very high accuracy, even when using av ariety of loudspeaker types (a single loudspeaker in abox, acube with six loudspeakers and ad odecahedron with twelvel oudspeakers). Unfortunately,intheir...

show abstract

Measuring Room Impulse Responses: Impact of the Decay Range on Derived Room Acoustic Parameters

Cited by 43 publications

References 6 publications

Acoustic modelling of sports halls, two case studies

Acoustic modelling of sports halls, two case studies

Room acoustic modelling of textile materials hung freely in space: from the reverberation chamber to ancient churches

The Sound Power as a Reference for Sound Strength (<I>G</I>), Speech Level (<I>L</I>) and Support (<I>ST</I>): Uncertainty of Laboratory and In-Situ Calibration

Contact Info

Product

Resources

About