The Bouba–Kiki Effect in Persons with Prelingual Auditory Deprivation

The “bouba–kiki effect” refers to the correspondence between arbitrary visual and auditory stimuli. Previous studies have demonstrated that neurodevelopmental conditions and sensory impairment affect subjects’ performance on the bouba–kiki task. This study examined the bouba–kiki effect in participants with severe-to-profound hearing loss. Sixteen participants with severe- to- profound hearing loss who were habilitated aurally and used oral language for everyday communication and 16 matched hearing peers were presented with the bouba–kiki task auditorily and orthographically. Verbal intelligence (Wechsler Adult Intelligence Scale–Third Edition) was determined for all participants and was similar in both groups. Our results demonstrate a reduced bouba–kiki effect in participants with severe-to-profound hearing loss compared to their hearing peers, though they performed above chance level. Moreover, the age at the first use of a hearing device was associated with participants’ performance on the bouba–kiki task in adulthood. Better performance was shown in participants who used a hearing device at infancy before 23 months of age. These results support a relationship between early auditory or linguistic deprivation, and performance on the bouba–kiki task, and are discussed in the light of the role of a sensitive period on the development of the effect. This study is the first to show that prelingual deafness affects cross-modal auditory–visual correspondence resulting in reduced sound symbolism.