Introducing diphthongs to the vowel space

Abstract

The aim of the study is to provide information on a new vowel space of Polish learners of British English, specifically about acoustic properties of diphthongs. Polish does not have diphthongs, though it has vowel plus glide sequences comparable to English rising diphthongs. Polish has neither vowel duration distinctions nor vowels which are qualitatively identical to the ones appearing in English diphthongs. Studying diphthongs offers the possibility of examining the interplay of substitutions of qualitative and quantitative features. Eight dipthongs were taken into account. The conditioning criteria were quality, duration, occurrence of glottal stops, and degree of nasalization. Twenty subjects were recorded reading 61 sentences with diphthongs embedded in real words. The paper discusses challenges in segmentation. Reported are non-native properties of formant and timing relations and systematic differences in alternations applied to: simple vowels versus diphthongs, rising versus centering diphthongs, and initial versus final phases of diphthongs. Specifically, nasal vocalization was found to depend on the presence or absence of a following fricative, but to be independent of a stressed or unstressed position. The finding is explained by resorting to Polish prosody, which is not stress timed. Suggestions for using the findings in second language instruction will also be offered.