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.