Phonemic and Lexical Use in Igbo–English Bilingual Aphasics

Abstract

This study investigates phonological and lexical impairments in the speech of Igbo/English bilingual aphasics, with a focus on how aphasia affects the realization of phonemes and the use of lexical items across the two languages. Aphasia is an acquired language disorder resulting from brain damage, most commonly caused by stroke, and it may impair language production and comprehension at various linguistic levels. Given Nigeria’s multilingual context and the widespread use of English alongside indigenous languages such as Igbo, bilingual aphasia presents a complex linguistic phenomenon that requires systematic investigation. The study adopts a descriptive research design and is grounded in the theoretical frameworks of structuralism and socio-communicative theory. Data were collected from three Igbo/English bilingual aphasic participants receiving medical care at the University of Port Harcourt Teaching Hospital. Speech samples were elicited through spontaneous conversation, question-and-answer sessions, and object/picture naming tasks. Phonetic transcription using the International Phonetic Alphabet (IPA) was employed for detailed phonological analysis, while lexical performance was assessed through word retrieval tasks in both languages. Findings reveal marked phonological impairments characterized by sound substitutions, deletions, and distortions in both Igbo and English. Notably, phonemes that are structurally complex or absent in one language were more vulnerable to impairment. Lexical analysis shows significant word-finding difficulties in both languages, with greater impairment observed in English (L2) than in Igbo (L1). The aphasics demonstrated slower lexical retrieval, use of inappropriate lexical items, and circumlocution, especially in L2. Overall, the study establishes that while both languages are affected by aphasia, the first language exhibits relative resilience. These findings have important implications for bilingual aphasia assessment and rehabilitation in multilingual contexts.