Free-field rooms need to be assessed with respect to acoustic quality as described in the relevant standards by sound pressure level decay tests that are compared to the expected decay of 6 dB per doubling of distance from the source. These tests are time consuming, as the microphone has to be moved along straight paths while recording the sound levels for each frequency. For this purpose, a new measuring system is described which accelerates the test procedure considerably with the aid of a self-propelled microphone positioning system and a computerized positioning and data analysis system.
References
1.
ISO 3745 – 2003: Acoustics – Determination of sound power levels of noise sources using sound pressure – Precision methods for anechoic and hemi-anechoic rooms.
2.
FuchsH.V.: Schallabsorber und Schalldämpfer – Innovative Akustik-Prüfstände. Berlin: Springer, 2004.
3.
FuchsH.V.: Broadband compact absorbers for anechoic linings. Joint Congress CFA/DAGA2004, Strasbourg, p. 955–956.
4.
DreyerW.: The new Volkswagen Acoustics Centre in Wolfsburg, Part 1: Test beds. ATZ Worldwide105 (2003), 3, p. 11–15.
5.
FuchsH.V.: The new Volkswagen Acoustics Centre in Wolfsburg, Part 2: Anechoic room linings. ATZ Worldwide105 (2003), 4, p. 19–23.
6.
BabukeG.: The new Volkswagen Acoustics Centre in Wolfsburg. Joint Congress CFA/DAGA2004, Strasbourg, p. 873–874.
7.
LechelerA.: Noise reduction and anechoic linings in aeroacoustic wind tunnels. Joint Congress CFA/DAGA2004, Strasbourg, p. 875–876.
8.
CunefareK. A.: Anechoic chamber qualification: Traverse method, inverse square law analysis method, and nature of test signal. J. Acoustic. Soc. Am.113 (2003), 2, p. 881–892.
