The aim of this paper is to investigate the phonetic properties of a Turkish vowel in which its backness is indefinite. The five members ([a],[epsilon],[i],[u] and the high unrounded Turkish vowel, in short HUTV) of the Turkish vowel system were investigated in five adult native Turkish speaker males. For the articulatory analysis, midsagittal magnetic resonance images were obtained during sustained phonation of the vowels, and the distances of the main constrictions from the glottis and the areas of the oral and pharyngeal cavities were calculated. For the acoustic analysis, both the Turkish vowels' and HUTV-Iike IPA vowels' fundamental frequencies (f(0)) and the first three formants (F-1, F-2 and F-3), were calculated. The acoustic parameters of HUTV were compared both with other vowels' and with those of the IPA vowels'. For the auditory analysis, 220 synthetic stimuli and 26 IPA vowels were used in an identification test. Articulatory analyses revealed that there were no statistically significant differences between HUTV and [u], and HUTV and [epsilon]. Acoustic analyses revealed that there were no statistically significant differences between HUTV and [epsilon], and HUTV and phoneticians' [+] and [w], and [v] vowels. Auditory investigation revealed that the [+] and [w], and [v] vowels perceived as HUTV. These results suggested that HUTV's position in the vowel space was between the [epsilon] and [u] vowels, but its subarea was fairly wide. (C) 2004 Elsevier B.V. All rights reserved.