Document Type: Original
Department of otorhinolaryngology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Ear, Nose, Throat, Head and Neck surgery Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Audiologist, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Department of otorhinolaryngology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
It has been shown that low levels of pigmentation increase susceptibility to noise-induced hearing loss in humans. For this reason, white populations develop more pronounced noise- induced hearing loss in comparison to black populations. Similarly, blue-eyed individuals exhibit greater temporary threshold shift than brown-eyed subjects; still, no strong correlation has been verified between the lightness of hair color and susceptibility to noise-induced hearing loss. This study was performed with the purpose of investigating a possible association between hair color and the degree of hearing loss due to firing noise. Study Design: Prospective observational study. Setting: A tertiary referral center with an accredited otorhinolaryngology-head & neck surgery department.
Materials and Methods:
A total of 57 military recruits were divided into two groups; light-colored (blond and light brown) and dark-colored hair (dark brown and black). The two groups were matched based on history of firing noise exposure (number of rounds; type of weapon) and the level of hearing loss at 2, 3, 4, 6 and 8 kHz sound frequencies was compared between them.
The results showed that the mean level of hearing loss of light-colored hair individuals
(20.5±17dB) was significantly greater than that of dark-haired subjects (13.5±11dB),
The results indicate that hair color (blond versus black) can be used as an index for predicting susceptibility to noise-induced hearing loss in military environments. Therefore, based on the individual's hair color, upgraded hearing conservation programs are highly recommended.