Experimental phonetics is a fundamental source of typological reconstructions. It provides plausible data on the phonetic processes progressing in a language, dialect, or subdialect. In this paper, we compare the results of MRI-investigation of the sound a (it being the most frequently used in the Turkic languages) in related though quite distant languages: Baraba-Tatar, Altai (Ust-Khan subdialect) and Bashkir (Eastern dialect). Thus, the purpose of our study is to distinguish the articulatory traits of the a-type sound in the Barabian, Altai and Bashkir languages under different positional and combinatory conditions as a result of somatic experimental-phonetic research. Magnetic-resonance imaging (MRI) of the vocal tunings was done from the native speakers of the three languages: Baraba-Tatar, Altai, and Bashkir. The static MRI images comprising a-type articulations were selected from the obtained database. The somatic analysis of the linguistic material was conducted in accordance with the technique practiced in the V. M. Nadelyayev’s Laboratory of Experimental-Phonetic Researches (IP SB RAS). Sound tomograms have been analyzed and interpreted, tomoschemes are presented for the visualization purpose. In total, 17 tomograms have been described. The authors have processed the linguistic and experimental material on three Turkic idioms and made a number of important conclusions. A -type sound is realized in the back row words in the languages under consideration, which coincides with the supposition about Turkic vowel harmony suggested earlier. In all languages under investigation the general tuning of the sound a is similar: it is central-back. But what makes it unique for every language is its additional characteristics. For example, in Barabian the phoneme /ʌ̇ ˘/ can be realized in pharyngealized, nasalized and labialized variants, while the Ust-Khan phoneme /ʌ̇ / is the most unified one (nonnasalized, rarely labialized and pharyngealized). The Eastern Bashkirian phoneme /ɤ̇/ resembles the Baraba-Tatar phoneme in many aspects. The statement (based on the perceptive analysis) about the use of more open and in some senses more backward, laryngeal and even pharyngealized sound a in some sub-dialects of the Eastern dialect of Bashkir did not turn out to be correct. According to the experimental data, all eastern Bashkir tunings appear to be central-back strongly shifted forward, i.e. the tongue does not move backward too much. Regarding the mouth openness, all variants of the Eastern Bashkirian sound a are half narrow (the third level of openness), and in some cases they can even be said to be narrow (the second level). Despite the territorial closeness of Altai (Ust-Khan sub-dialect) and Baraba-Tatar, the comparative analysis of the articulatory peculiarities of the vocal tunings under discussion revealed close correlation between Barabian and Eastern Bashkirian realizations of sound a. It might be accounted for by similar ways of their development (both of historical and immanent character) as well as by the literary Tatar language and its dialects influence on Baraba-Tatar (an intensive wave of immigrants from the Volga-Ural region into Baraba Steppe where Baraba-Tartars had been historically living was recorded in the beginning of the 20th century). To sum up, the further investigation of all vocal system units is necessary to make final conclusions about typological likelihood or diversity of the languages under consideration.