In search of an inherent ordering of vowel phonemes, or do pilots hear like engineers do?

To test the hypothesis that formant frequencies might provide an inherent ordering scheme for vowel sounds, two groups of subjects were asked to place six Italian vowel phonemes (A, O, U, AE, E, and I) into the most musically pleasing order. A subsequent chi 2 analysis of selections of the first group (21 music students and engineers) indicated a reliable consistency in vowel order supporting the hypothesis. Analysis of the second group (12 pilots) did not indicate any consistent ordering. The results are discussed in terms of hearing damage associated with exposure to high frequency aircraft noise.