This thesis presents experiments and interviews which investigate pronunciation variation in the Liverpool accents of young speakers. Experiment One investigates inter-speaker variation, Experiment Two investigates intra-speaker variation, and Experiment Three investigates both inter- and intra-speaker variation. These three experiments are conducted from a sociophonetic perspective, with controlled elicitation of natural speech and acoustic analysis of speech data. The experimental investigations are complemented by interviews, which incorporate the perceptions and opinions of speakers of Liverpool English into the study. The study makes several contributions to the field of sociolinguistic research. It provides a new examination of Liverpool English. Experiment One is specifically designed to explore one of its most complex and ill-defined phonetic features, the realisation of plosives as affricates or fricatives. In addition to this phonetic investigation, Experiment One also examines sociolinguistic variation in this feature, and shows that speakers' individual attributes (such as their social networks and their plans for the future) are as relevant to variation as their socio-economic status. The study also makes important methodological contributions. Instrumental phonetic techniques and standards are successfully applied to sociolinguistic investigation conducted in the field. An interdisciplinary approach, bringing together qualitative interviews and sociophonetic experiments, is adopted. A new quiz-questionnaire technique for data collection, which should prove useful for many kinds of future sociolinguistic research, is developed for Experiment Three. Finally, Experiment Three tests many accounts and models of intra-speaker variation. Speakers are shown to vary their pronunciation as the speech situation varies, but not all the seven phonetic variables investigated show the same patterns of variation. Speakers vary their pronunciation according to audience, and also according to topic. Speakers with a high level of ambition vary their pronunciation of certain phonetic variables more than those with a lower level of ambition, and female speakers vary their pronunciation more than male speakers.