Distinctive Features - Speech Resource Pages - Macquarie University

onglide ([ ə iː]) of broad speakers, through the shorter, but acoustically similar,
onglide of general speakers to the short onglide (something like [ ɪ iː]) of cultivated
speakers.
For those Australian English speakers who move between [ɪə] and [ɪːɹ] sequences
in different phonetic contexts, the phoneme /ɪə/ may (according to
transformational theory) be described to be "underlyingly" a sequence of the
phonemes /ɪ/ + /r/ (or perhaps /iː/ + /r/). If this is so, then the process of
monophthongisation of the centring diphthongs may be the result of a more
fundamental process whereby the underlying /r/ component of the sequence is
deleted. Even in American English, which is a rhotic dialect of English, the surface
representations of the underlying post-vocalic /r/ phonemes varies greatly. In
American English /ə˞/ the following /r/ is most often entirely represented by the
surface rhoticisation of the vowel. In the Eastern New England variety of
American English the post-vocalic /r/ in many words is not as rhoticised as is the
case of most American English varieties, but the /r/ still exists as an alveolar, but
not retroflexed, approximant (Olive et al, 1993, p367).
The next table represents a possible feature representation for the three high
front vowels of Australian English speakers. The feature "onglide" is proposed
here as a feature that accounts for the virtually universal existence of an on-glide
for /i:/ in Australian English.
Feature table for Australian English /iː/,/ɪ/ and /ɪə/
high low front back round tense onglide
/iː/ = [ ə iː] [ ɪ iː] + - + - - + +
/ɪ/ = [ɪ] + - + - - - -
/ɪə/ = [ɪə] [ɪː] + - + - - + -
c) Feature Analysis of Diphthong Vowels
Diphthongs are single vowels with two targets. In other words the tongue must
attempt to move from one position to another in order for the diphthong to be
fully pronounced.
In the following discussion /eː/ is excluded because it as regarded as a tense
monophthong (with an optional offglide) and /ʊə/ is excluded because it is either
extinct or is almost extinct.
One way of performing a distinctive feature analysis of diphthongs is to analyse
each target separately. This type of analysis appears to assume that diphthongs
are "underlyingly" a sequence of two monophthongs. In this approach, each
target would be allocated a full set of features. This approach has the advantage
of not requiring the invention of new features. Its weakness is that implicitly it
treats diphthongs as two vowels.
In Australian English all diphthongs are pronounced with distinct first targets and
very brief or sometimes absent second targets. They are realised as having a
clear first target followed by a long offglide in the direction of some intended
second target, which may have a very short or even a zero length. In unaccented
contexts (i.e. not affected by sentence stress) diphthongs may be reduced to a
monophthong (often similar to the first target) or even to schwa.