The Influence of Skin Pigmentation on Cochlear Functioning: A Study on Individuals with Normal Hearing Sensitivity

Abstract

Background and Aim: Melanocytes are cells in the skin, hair, and eyes that generate pigment called melanin, which is primarily responsible for the pigmentation of these structures. These melanocytes, known as the Cochlear Melanocyte, are also present in the human ears (especially in the cochlea) and play a significant role in fostering endocochlear potential and preventing the odds of hearing loss. The current study investigated the relationship of skin pigment with cochlear function through distortion product otoacoustic emission in Indian skin type. Methods: A total of 120 participants aged between 17 to 25 were included using a purposive sampling technique. The subjects were further grouped based on a questionnaire on Fitzpatrick Skin Phototype (FSP) developed by Thomas Fitzpatrick (1975) and categorized as type III- type VI suitable for Indian skin types. Along with routine audiometric evaluations, the cochlear functioning was assessed using distortion product otoacoustic emissions. The standard group research design was used, and as data was normally distributed, multivariate analysis of variance was used to compare across groups. Results: The results of multivariate analysis of variance (MANOVA) showed no significant differences across the four groups for both amplitude and the slope of distortion product otoacoustic emissions. Conclusion: The present study using otoacoustic emissions revealed that the skin pigmentation did not affect cochlear functioning in the Indian population (type III through type VI) as seen in type I and II. Keywords: Melanocytes; hearing loss; cochlear function; skin pigmentation