Time-Frequency Analysis of High-Intensity, Fast Transient Noise from Power Tools by Analytic Wavelet Transform

Using two types of portable power tools as examples, this paper explains that a time-frequency analysis is necessary to properly characterize highly impulsive sound. Between the two tools, the noise generated by the impact wrench is more highly transient compared to the jigsaw noise. The paper shows that the characteristics, and therefore the related risks, of such noises cannot be severely underestimated unless accurate time-frequency analysis is utilized. The paper proposes the analytic wavelet transform as an ideal signal analysis tool to characterize such highly transient sounds. It is explained that the transform provides the advantages of both the wavelet transform and the Fourier transform. The transform can be interpreted as a transient spectral analysis, which will open up many interesting applications. While the transform can be used to study the response characteristics of any dynamic system, it is especially useful in acoustics applications because of its resemblance to the way our auditory system processes sound signal. The long-term plan of this paper is to develop a method for quantitative risk assessment of impact noise induced hearing loss and this paper summarizes the first stage of this long term effort.


  • English

Media Info

  • Media Type: CD-ROM
  • Features: References;
  • Pagination: pp 306-312
  • Monograph Title: Noise-Con 04. The 2004 National Conference on Noise Control Engineering

Subject/Index Terms

Filing Info

  • Accession Number: 01054209
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jul 16 2007 5:36PM