We've taken under comparative examination the phonation of people having full upper and lower dentures and the ones having normal teeth. We've tested twenty 51 to 65 years old persons having their dentures at least for a year being pleased with them (well speaking and chewing normally) and twenty persons (without distinction as to sex) having normal teeth normal occlusion. The investigation of the articulation was compiled a lingual corpus consisted of texts of different length (words, word-groups, sentences and text-pieces). This material was suitable for the examination of disorders of the articulation, the pronunciation of the sound combinations, the articulatory problems, and the suprasegmental components (e.g. melody, speech tempo, dynamics of speech). The experimental material was prepared by the following instruments: an VII (Voice Identification, Inc.) 700 series sound spectrograph, an IBM compatible computer with acoustic analytical programs suitable for the investigation of selected sound samples by an A/D (analog/digital) converter, the number of sounds in a second was measured with a 8SO-4 type oscillograph. The results can be summarized as follows: 1. various differences appear among the speech structures of persons having full upper and lower dentures: the labial [b p m], labiodental [v f ], dental, dentialveolar [d t n z s dz ts l r], alveolar [symbol: see text] and prepalatal [symbol: see text] consonants distort principally. 2. From the long consonants the voicelles stops (p: t: k:) are short-ended especially.(ABSTRACT TRUNCATED AT 250 WORDS)