Perceptually motivated wavelet packet transform for bioacoustic signal enhancement

Yao Ren, Michael T. Johnson, Jidong Tao

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


A significant and often unavoidable problem in bioacoustic signal processing is the presence of background noise due to an adverse recording environment. This paper proposes a new bioacoustic signal enhancement technique which can be used on a wide range of species. The technique is based on a perceptually scaled wavelet packet decomposition using a species-specific Greenwood scale function. Spectral estimation techniques, similar to those used for human speech enhancement, are used for estimation of clean signal wavelet coefficients under an additive noise model. The new approach is compared to several other techniques, including basic bandpass filtering as well as classical speech enhancement methods such as spectral subtraction, Wiener filtering, and Ephraim-Malah filtering. Vocalizations recorded from several species are used for evaluation, including the ortolan bunting (Emberiza hortulana), rhesus monkey (Macaca mulatta), and humpback whale (Megaptera novaeanglia), with both additive white Gaussian noise and environment recording noise added across a range of signal-to-noise ratios (SNRs). Results, measured by both SNR and segmental SNR of the enhanced wave forms, indicate that the proposed method outperforms other approaches for a wide range of noise conditions.

Original languageEnglish
Pages (from-to)316-327
Number of pages12
JournalJournal of the Acoustical Society of America
Issue number1
StatePublished - 2008

Bibliographical note

Funding Information:
This material is based on work supported by National Science Foundation under Grant No. IIS-0326395. The authors also want to express their thanks to Joseph Solitis and John D. Newman for providing the rhesus monkey vocalizations, T. S. Osiejuk for providing the ortolan bunting vocalizations, and Mobysound for providing the humpback whale vocalizations.

ASJC Scopus subject areas

  • Arts and Humanities (miscellaneous)
  • Acoustics and Ultrasonics


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