Detection of glottal closure instant and glottal open region from speech signals using spectral flatness measure

Research output: Contribution to journalArticleScientificpeer-review


Research units

  • IDIAP Research Institute
  • International Institute of Information Technology Hyderabad


This paper proposes an approach using spectral flatness measure to detect the glottal closure instant (GCI) and the glottal open region (GOR) within each glottal cycle in voiced speech. The spectral flatness measure is derived from the instantaneous spectra obtained in the analysis of speech using single frequency filtering (SFF) and zero time windowing (ZTW) methods. The Hilbert envelope of the numerator of group delay (HNGD) spectrum at each instant of time is obtained using the ZTW method. The HNGD spectrum highlights the important (like resonances) spectral characteristics of the vocal tract system at each instant of time. The dynamic characteristics of the vocal tract system can be tracked by the spectral flatness feature of the HNGD spectrum, thus bringing out the characteristics of the vocal tract system when the subglottal region is coupled with the supraglottal region during the open phase of the glottal cycle. The SFF spectra at each instant change significantly at the location of the GCI. The GCIs can be detected using the changes in the spectral flatness information derived from the SFF spectra. The proposed methods of detection of GCI and GOR is compared with several existing methods.


Original languageEnglish
Pages (from-to)30-43
JournalSpeech Communication
Early online date12 Nov 2019
Publication statusPublished - Jan 2020
MoE publication typeA1 Journal article-refereed

    Research areas

  • Excitation source, Glottal Closure Instants, Glottal open region, Single frequency filtering, Speech analysis, Zero time windowing

ID: 38673666