AGE-RELATED VARIATION IN SPEECH ARTICULATION: A PHONETIC AND PHONOLOGICAL ANALYSIS OF YOUNG AND OLDER NIGERIAN ENGLISH SPEAKERS

Abstract

This study investigates age-related variations in speech articulation among Nigerian English speakers. It compares young adults (18–35 years) and older adults (65 years and above) to examine how physiological and cognitive changes associated with aging affect articulatory precision, fluency, and segmental production. Drawing on Speech Motor Control Theory and Cognitive Load Theory, the study distinguishes normal age-related phonetic changes from potential pathological conditions within the Nigerian English context. The research adopted a mixed-methods approach. Although 60 participants (30 young adults and 30 older adults) were initially recruited in the Onitsha urban area, complete data were obtained from and analysed for 28 participants, comprising 10 young adults and 18 older adults. Data were collected through structured questionnaires, semi-structured interviews, observations, and a controlled speech corpus. The corpus included diadochokinetic tasks, the reading of a standardized passage, and spontaneous speech. Recordings were analysed using phonetic transcription and Praat software for acoustic measurements. The findings revealed noticeable differences between the two age groups. Older speakers produced more consonant substitutions and omissions, vowel reductions, temporal disfluencies, longer pauses, and reduced vocal intensity. In many cases, these patterns were associated with hearing loss and dental challenges. Younger speakers, on the other hand, exhibited greater articulatory stability and smoother fluency during speech production. The study argues for context-sensitive speech intervention strategies that reflect the realities of Nigerian English rather than relying entirely on foreign speech models.