Introduction

Differences in pronunciation between different regional, national and social accents of languages are immediately striking even to non-linguists. While a small number of these differences are purely incidental, for example the fact that the second vowel in tomato is pronounced /a/ in Southern Standard British English but /eɪ/ in Standard American English, most differences between accents of any language are systematic. This systematic variation can be analysed with reference to a large number of phonological domains and structures and different phonological and phonetic processes. On the segmental level (see Gut, Chapter 13, this volume, for variation on the suprasegmental level), these include:

1. the phoneme inventory (vowels and consonants),

2. the phonetic realization of vowels and consonants, and

3. the phonotactic distribution of phonemes.

In recent years, many research methods for exploring phonological and phonetic variation on the segmental level have become established. Moreover, a number of new methods have become available, some of which have not yet been applied to this area. In the following sections, both the widely used and some new methods will be presented and discussed. Section 2 is concerned with the analysis of vowels in terms of phoneme inventory (Section 2.1), their phonetic realization (Section 2.2) and their articulation (Section 2.3). Section 3 evaluates methods of studying consonants: the consonant inventory (Section 3.1), their phonetic realization (Section 3.2) and their articulation (Section 3.3).