Abstract
The results of an on-line study of vowel recognition by English speakers are analysed:A relatively unused region of the perceptual vowel plane is identified at about (F2, F1) = (1800 Hz, 350 Hz). The rest of the plane is divided among vowels in ways that differ somewhat for different countries and regions thereof. Vowel length is used in several cases to help distinguish vowels whose distributions overlap substantially in (F2, F1). When the fundamental frequency is higher, the values of F1 and F2 are also higher, though much less than proportionally. This is consistent with the observation that women's vocal tracts are usually shorter than men's. The characteristic separations required to distinguish vowels in the (F2, F1) plane were 115 Hz and 292 Hz in the F1 and F2 directions respectively, with similar values in different countries.