Skip to main navigation menu Skip to main content Skip to site footer
FrancoAngeli Journals

Technical notes

Vol. 48 No. 2 (2024)

Experimental survey on the instrumental noise in acoustic measurements and those at very low sound levels

DOI
https://doi.org/10.3280/ria2-2024oa18214
Submitted
luglio 23, 2024
Published
2024-12-18

Abstract

The work describes the results of an experimental investigation aimed at determining the self-generated noise from the instrumentation used for acoustic measurements which, in case of measurements at low levels, is often comparable with the one to be detected and, thus, invalidating the acquired data. The instrumental noise, which is random in nature, can be determined by the “Coherent Output Power, COP” analysis and, therefore, allowing to mask it from the measurement. The COP function can also be used to measure very low noise levels.

 

 

References (including DOI)

  1. V. Tarnow, Thermal Noise in Microphones and Preamplifi-ers, Brüel & Kjær Technical Review, 3 (1972) 3-14.
  2. E. Frederiksen, Microphone System for Extremely Low Sound Levels, Brüel & Kjær Technical Review, 3 (1984) 16-22.
  3. P.K. Møller, Measurement of Background Noise in Sound-Insulated Rooms, Journal of Sound and Vibration 85 (1982) 143-150.
  4. R.M. Ellingson, F.J. Gallun, G. Bock, Measurement with verification of stationary signals and noise in extremely quiet environments: Measuring below the noise floor, J. Acoust. Soc. Am. 137 (2015) 1164–1179 DOI: 10.1121/1.4908566.
  5. A. Armani, La misura di livelli sonori molto bassi ‘Sot-toZeroDB’, Spectra S.r.l. Nota tecnica 1-2016.
  6. Institute of Electrical and Electronics Engineers (IEEE) Standard Dictionary of Electrical and Electronic Terms, Wiley, 1997.
  7. G.V. Pallottino, Il rumore elettrico. Dalla fisica alla pro-gettazione, Springer-Verlag Italia 2011.
  8. J.B. Johnson, Thermal Agitation of Electricity in Conduc-tors, Physical Review 32 (1928) 97–109 DOI: 10.1103/PhysRev.
  9. 97.
  10. H. Nyquist, Thermal Agitation of Electric Charge in Con-ductors, Physical Review 32 (1928) 110–113 DOI: 10.1103/PhysRev.
  11. 110.
  12. V. Radeka, 1/f Noise in Physical Measurements, IEEE Transactions on Nuclear Science 16(1969) 17-35 DOI: 10.1109/TNS.
  13. 4325473.
  14. Microphone Handbook, Brüel & Kjær Technical Docu-mentation 1 (2019).
  15. W. Schottky, Über spontane Stromschwankungen in verschiedenen Elekrizitätsleitern, Annalen der Physik 57 (1918) 541-567 DOI: 10.1002/andp.19183622304.
  16. W.R. Bennett, Spectra of quantized signals, Bell Syst. Tech. J. 27 (1948), 446-472 DOI: 10.1002/j.1538-7305.1948.tb01340.x.
  17. J.S. Bendat, W.G. Halvorsen, Noise source identification using coherent output power spectra, Sound and Vibra-tion 9 (1975) 18–24.
  18. M. Nevrela, M. Weisz, J. Szweda, M. Vasina, Removing additive noise in measurements of low sound pressure levels, MM Science Journal (2020) DOI: 10.17973/MMSJ.2020_10_
  19. A. Armani, F. Pompoli, Misura del rumore di fondo nella camera anecoica dell’Università di Ferrara con il metodo della Coherent Output Power(COP), 3°Seminario Acustica e Industria "Tecniche innovative per il controllo del ru-more e delle vibrazioni dei prodotti industriali", Ferrara, 15 febbraio 2018.
  20. O.-H. Bjor, Measurement of Extremely Low Sound Pres-sure Levels, Proc. InterNoise 1997, Budapest, Hungary, 1555-1558.

Metrics

Metrics Loading ...