title: A study of lip movements during spontaneous dialog and its application to voice activity detection.
abstract: This paper presents a quantitative and comprehensive study of the lip movements of a given speaker in different speech/nonspeech contexts, with a particular focus on silences (i.e., when no sound is produced by the speaker). The aim is to characterize the relationship between "lip activity" and "speech activity" and then to use visual speech information as a voice activity detector (VAD). To this aim, an original audiovisual corpus was recorded with two speakers involved in a face-to-face spontaneous dialog, although being in separate rooms. Each speaker communicated with the other using a microphone, a camera, a screen, and headphones. This system was used to capture separate audio stimuli for each speaker and to synchronously monitor the speaker's lip movements. A comprehensive analysis was carried out on the lip shapes and lip movements in either silence or nonsilence (i.e., speech+nonspeech audible events). A single visual parameter, defined to characterize the lip movements, was shown to be efficient for the detection of silence sections. This results in a visual VAD that can be used in any kind of environment noise, including intricate and highly nonstationary noises, e.g., multiple and/or moving noise sources or competing speech signals.
authors.affiliation: Department of Speech and Cognition, GIPSA-lab, UMR 5126 CNRS, Grenoble-INP, Université Stendhal, Université Joseph Fourier, Grenoble, France.
authors.forename: David
authors.initials: D
authors.lastname: Sodoyer
authors.forename: Bertrand
authors.initials: B
authors.lastname: Rivet
authors.forename: Laurent
authors.initials: L
authors.lastname: Girin
authors.forename: Christophe
authors.initials: C
authors.lastname: Savariaux
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Schwartz
authors.forename: Christian
authors.initials: C
authors.lastname: Jutten
mesh_terms: D000465:Algorithms; D003463:Cues; D006801:Humans; D008046:Lip / Q000502:physiology*; D008085:Lipreading; D008297:Male; D009068:Movement; D010363:Pattern Recognition, Automated; D046709:Pattern Recognition, Physiological; D017603:Signal Detection, Psychological; D013018:Sound Spectrography; D013067:Speech Perception; D014741:Video Recording; D014796:Visual Perception; D014831:Voice