Hilbert phase methods for glottal activity detection
|Institution:||University of Illinois Urbana-Champaign|
|Keywords:||Hilbert phase; Analytic phase; Electroglottograph (EGG); Glottal closure instant (GCI)|
|Full text PDF:||http://hdl.handle.net/2142/97304|
The 2 pi discontinuities found in the wrapped Hilbert phase of the bandpass-filtered analytic DEGG signal provide accurate candidate locations of glottal closure instances (GCIs). Pruning these GCI candidates with an automatically determined amplitude threshold, found by iteratively removing from the full signal the inlier samples within a fraction of its standard deviation until converged, yields a 99.6% accurate detection system with a false alarm rate of 0.17%. This simpler algorithm, named Glottal Activity Detector For Laryngeal Input (GADFLI), outperforms the state-of-the-art SIGMA algorithm for GCI detection, which has a 94.2% detection rate, but a 5.46% false alarm rate. Performance metrics were computed over the entire APLAWD database, using an extensive, hand-verified markings database of 10,944 waveforms. A related proposed algorithm, QuickGCI, also makes use of Hilbert phase discontinuities, and does not require a thresholding post-processing step for GCI selection. Its performance is nearly as good as GADFLI. Both proposed algorithms operate using the electroglottographic signal or acoustic speech signal.Advisors/Committee Members: Hasegawa-Johnson, Mark (advisor), Hasegawa-Johnson, Mark (Committee Chair), Levinson, Stephen (committee member), Oelze, Michael (committee member), Viswanath, Pramod (committee member).