Automatic time-frequency analysis of echolocation signals using the matched Gaussian multitaper spectrogram

Research output: Contribution to journalArticle

Abstract

High-resolution time-frequency (TF) images of multi-component signals are of great interest for visualization, feature extraction and estimation. The matched Gaussian multitaper spectrogram has been proposed to optimally resolve multi-component transient functions of Gaussian shape. Hermite functions are used as multitapers and the weights of the different spectrogram functions are optimized. For a fixed number of multitapers, the optimization gives the approximate Wigner distribution of the Gaussian shaped function. Increasing the number of multitapers gives a better approximation, i.e. a better resolution, but the cross-terms also become more prominent for close TF components. In this submission, we evaluate a number of different concentration measures to automatically estimate the number of multitapers resulting in the optimal spectrogram for TF images of dolphin echolocation signals. The measures are evaluated for different multi-component signals and noise levels and a suggestion of an automatic procedure for optimal TF analysis is given. The results are compared to other well known TF estimation algorithms and examples of real data measurements of echolocation signals from a beluga whale (Delphinapterus leucas) are presented.

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Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Signal Processing

Keywords

  • Concentration measures, Dolphin echolocation signals, Multi-component signals, Time-frequency analysis
Original languageEnglish
Pages (from-to)3048-3052
Number of pages5
JournalProceedings of the Annual Conference of the International Speech Communication Association, INTERSPEECH
Volume2017-August
Publication statusPublished - 2017
Publication categoryResearch
Peer-reviewedYes