The Lombard effect refers to the speech changes due to the immersion of the speaker in a noisy environment. Among these changes, studies have already reported acoustic modifications mainly related to the vocal tract behaviour. In a complementary way, this paper investigates the variation of the glottal flow in Lombard speech. For this, the glottal flow is estimated by a closed-phase analysis and parametrized by a set of time and spectral features. Through a study on a database containing 25 speakers uttering in clean and noisy environments (with 4 noise types at 2 levels), it is highlighted that the glottal source is significantly modified due to the increased vocal effort. Such changes are of interest in several applications of speech processing, such as speech or speaker recognition, or speech synthesis.
Bibliographic reference. Drugman, Thomas / Dutoit, Thierry (2010): "Glottal-based analysis of the lombard effect", In INTERSPEECH-2010, 2610-2613.