@article{, title = {Significance of 6 khz in noise induced hearing loss in Indian Air Force personnel}, author = {Satish and Kashyap, RC}, abstract = { Noise is the most pervasive hazardous agent at industrial workplaces. Generally, noise induced hearing loss (NIHL) is a sensorineural hearing deficit which begins at higher frequencies (3000 to 8000 Hz) and gradually extends to lower / speech frequencies with chronic exposure to noise. The involvement of various high frequencies in the Indian Air Force (IAF) personnel with NIHL was analysed to evaluate the significance of involvement of 6 kHz. A study of the assessment of noise environment and audiometric analysis of IAF personnel was carried out at an operational IAF base. 229 personnel with audiometric evidence of NIHL were analysed for the distribution of hearing loss in the various frequencies. The study revealed that the maximum noise level exceeded the safe limit indicating that the noise environment is hazardous with the potential for adverse effects on the personnel. The IAF personnel in this study with NIHL showed a significantly higher involvement of 6 kHz as compared to other frequencies. A large proportion of personnel presented with audiometric notch at 6 kHz (57.3%) as compared to 4 kHz (34.3%). The classical audiometric notch at 4 kHz (Aviators Notch) as mentioned in the literature as pathognomic of NIHL was seen replaced by 6kHz notch in a significantly large number of personnel. This study emphasizes the importance of early involvement of 6 kHz in the present noise environment in detecting NIHL. }, volume = 52, journal = {Indian Journal of Aerospace Medicine}, issn = {0970-6666}, issn = {2582-5348}, }