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  • Research Article
  • Open Access

Removing the Influence of Shimmer in the Calculation of Harmonics-To-Noise Ratios Using Ensemble-Averages in Voice Signals

  • 1Email author,
  • 1,
  • 1,
  • 1 and
  • 1
EURASIP Journal on Advances in Signal Processing20092009:784379

  • Received: 1 November 2008
  • Accepted: 13 April 2009
  • Published:


Harmonics-to-noise ratios (HNRs) are affected by general aperiodicity in voiced speech signals. To specifically reflect a signal-to-additive-noise ratio, the measurement should be insensitive to other periodicity perturbations, like jitter, shimmer, and waveform variability. The ensemble averaging technique is a time-domain method which has been gradually refined in terms of its sensitivity to jitter and waveform variability and required number of pulses. In this paper, shimmer is introduced in the model of the ensemble average, and a formula is derived which allows the reduction of shimmer effects in HNR calculation. The validity of the technique is evaluated using synthetically shimmered signals, and the prerequisites (glottal pulse positions and amplitudes) are obtained by means of fully automated methods. The results demonstrate the feasibility and usefulness of the correction.


  • Information Technology
  • Quantum Information
  • Speech Signal
  • Ensemble Average
  • Full Article

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Authors’ Affiliations

Center for Studies on Electronics and Information Technologies, Central University of Las Villas, C. Camajuaní, km 5.5, Santa Clara, CP, 54830, Cuba


© Carlos Ferrer et al. 2009

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.