Abstract : In this dissertation, I demonstrate that the realization of the Spanish glottalization accounted for in Yucatán, México, differs depending on its position in the word and the linguistic ability of the speaker. The glottalization of an intervocalic stop is distinguished from a final glottalization by a distinct action of the glottis. I document these physiological differences by acoustic analyses and by the use of laryngography. The discrepancy in question appears in the VOT (voice-onset time), which is significantly shorter for glottal consonant than for the glottalized stops of all Yucatecan speakers. Likewise, the explosive noise response (resonance) is weaker in the glottal stop. This last effect results from a temporal shift that is established between the articulators of the oral cavity and the glottis to produce these glottalized stops. The location of energy concentration of the explosion and the duration of the glottalized stop and glottal consonant are influenced by their position in the word. They also vary according to whether the speaker is bilingual or mono-lingual. The glottal consonant (between two vowels or in initial or final position) considered by some mayan phoneticians as a glottal stop, is produced more like a glottal fricative in initial position and like a glottal stop or a glottal fricative in final position by Yucatecan.