Performance Evaluation of Aviation Headset in Indian Army

Passive hearing protective devices, referred also as ear defenders, work by obstructing noise propagation through the ear canal of the receiver. These gadgets are a popular choice as they offer high attenuation over a broad frequency range, though at times inadequately, especially in the low frequency region, as per International Standards of occupational exposure to noise. Upward masking of speech signal by low frequency noise also degrades the intelligibility of speech in noise that may lead to decrement in performance and hamper the safety of individualsworking in noisy occupational environments. Active noise reducing hearing protective devices lend the possibility of avoiding these problems particularly where the major acoustic energy is centered at low frequencies, rendering these active contraptions a powerful tool in preventing noise induced hearing loss without hampering speech/oralcommunication. Accordingly, the present study was undertaken to investigate the potential of Telex Stratus 30 Headset in providing protection against noise induced hearing loss and to evaluate its efficacy in improving the speech intelligibility of our Armed forces personnel working in different noise spectral environment

Implications and Prevention of Noise Hazards on Board Ships

Seafarers are exposed to intense noise due to running of powerful gas turbines present in the engine room and in other compartments due to the operation of various sub systems that adversely affect their hearing acuity and proficiency. A large body of persons is employed in the Shipping industry and it is of paramount importance to preserve and promote health in the work place. Hence, this particular study was undertaken with a view to precisely quantify the noise levels associated with the operation of turbine engines and examine the impact of exposure on hearing sensitivity of the individuals. The preventive measures that can control the adverse effects like the use of ear defenders, and, supplementation of carbogen, a mixture of 5% CO2 and 95% O2 were examine

Moderate noise associated oxidative stress with concomitant memory impairment, neuro-inflammation and neurodegeneration

Noise, a disturbing and unwanted sound is currently being perceived as a widespread environmental stressor. In the present study we investigated the activation of oxidative stress as a mechanism involved in cognitive impairment through changes in neuro-inflammation.Sprague Dawley rats (200-220 ​ ​g ​m) were exposed to moderate (100dB) sound pressure level (SPL) noise daily for 2 ​h ​s over a period of 15 and 30 days and the consequence on brain regions of hippocampus observed through behavioral studies by Morris Water Maze to assess effects on spatial memory coupled with biochemical evaluation of markers of oxidative stress and inflammation. Further, the underlying mechanism pertaining to apoptosis was investigated by immuno-histological studies through assessment of Caspase-3 and TUNEL assay as well as morphological parameters, namely Nissl bodies in CA1, CA3 and DG regions of hippocampus.Poorer performance in the MWM indicative of decrement in concept formation, attention, working memory, and reference memory was observed on 15 and 30 days of noise exposures. At the cellular level, increased oxidative stress and inflammation was noticed as evinced by elevated levels of TNF-α, IL-6, IL-1α and IFN-γ in both hippocampus and plasma. Exposure to noise also led to a gradual increase in the number of pyknotic and apoptotic neurons together with the increase in DNA fragmentation in hippocampus. Increased levels of inflammatory genes (i.g.) ccl2, ccr5, ifng, il13, il1a, tnfa coupled with decreased levels of bmp2 and il3 genes were found in both the noise exposure groups.Our findings revealed that moderate intensity noise exposure impaired early memory changes in expression of several gene families including genes associated with regulation of transcription, inflammatory response, and, response to oxidative stress