PHONETIC CHARACTERISTICS OF POST-STROKE SPEECH AMONG IGBO SPEAKERS: AN ACOUSTIC ANALYSIS

Abstract

Post-stroke speech impairment may affect the coordination of the articulatory, phonatory and temporal processes involved in speech production. This study examines the phonetic characteristics of post-stroke speech among Igbo speakers through a comparative acoustic analysis of ten (10) post-stroke and ten (10) neurologically healthy speakers. The post-stroke speakers were recruited from Nnamdi Azikiwe Teaching Hospital, Nnewi and Nwakaibe Wellness Home, Enugwu-ukwu while the control group were purposely selected across Awka axis to match with age and gender. Speech samples were recorded in controlled conditions and analysed using Praat, with attention to formant frequencies, fundamental frequency, intensity, duration, Voice Onset Time (VOT), speech rate and pause patterns. The findings reveal differences between the two groups across articulatory, phonatory and temporal dimensions. The post-stroke participants generally exhibited lower pitch and intensity values, variability in formant characteristics and segmental duration, differences in VOT, and altered speech timing. While speech rate varied considerably across participants, the post-stroke speakers consistently produced more frequent and longer pauses than their control counterparts. The findings suggest that post-stroke speech cannot be adequately characterised as simply slower or less precise; rather, it reflects a multidimensional disruption in the coordination of speech production.