The sequences of adjacent vowels in many languages evoke a complex problem that views the quantity and the quality of the phonic elements the hiatus consists of. In this case those two adjacent vowels are separated in two different syllables, producing a vocalic continuity called hiatus. During the process of articulation, one of the vowels loses its syllabic character, being included into a single syllable. During a thorough research it came out that the spoken language sues a general predisposition of simplifying the act of communication. Many languages disallow hiatus, avoiding it either by deleting or assimilating the vowel, or by adding an extra consonant. The aim of the article is to highlight the distinctive articulatory and acoustic features of /ıə/diphthong versus adjacent vowels having /ı/ as a first element of hiatus, and to compare their quantitative and qualitative features.