Evaluation of acoustic shock induced early hearing loss with audiometer and distortion product otoacoustic emissions.

Background: Acoustic shock injury has been described as a permanent injury to the auditory system either due to daily noise dose of in excess of 85 decibels or very loud impulse sound reputed to be in excess of 120 decibels and acoustic incidents. This study was performed to compare the results of audiogram and the newer diagnostic method distortion product otoacoustic emissions (DPOAEs) parameters due to acoustic shock injury in call center professionals working in a noisy environment and prone to acoustic injury. Materials and Methods: Hearing functions of 340 subjects were first assessed with pure tone audiometry and then DPOAEs results were compared among acoustic shock exposed subjects with normal audiogram and those with abnormal audiogram. Results: Out of 340 acoustic shock exposed subjects 304 were normal on audiometric testing and 34 had abnormal audiograms. Subsequently on DPOAE testing out of 304 acoustic shock exposed subjects with normal audiogram 125 failed and 181 passed. Conclusions: This study showed that DPOAEs are more sensitive than audiometry to detect pre-symptomatic inner ear damage. It may play a role as screening and monitoring test for acoustic shock-exposed workers.

A comparative study of cardiopulmonary efficiency in athletes and non-athletes.

This study was aimed to determine during exercise the maximum related oxygen transport viz, maximum heart rate (max HR), dyspnoeic index (DI), oxygen pulse (O2 pulse), recovery heart rate in an athletic and a non-athletic group. Both study groups were subjected to graded treadmill exercise testing and pulmonary function test (PFT) was done using an electronic spirolyser. Results were compared and analysed. Significantly higher values in athletes were observed as compared to non-athletes regarding the following parameters: VO2 max, V(E) max, delta heart rate and max O2 pulse where resting heart rate, DI at VO2 max and recovery heart rate were lower in athletes while there was no significant change in both the groups in observed value of: MW, BR at VO2 max HR. The observations suggest an overall higher adaptability of the cardiovascular system and the relative refractoriness of the respiratory system to the effects of training and the maximum oxygen consumption in both the groups show similar values as that from otherparts of the country while MW, V(E) max, BR at VO2 and DI at VO2 max differ. A higher delta heart rate in athletes suggests a lesser risk for cardiovascular mortality in this group.

A study of peak expiratory flow rates among tribal children of Mysore District.

In the context of a growing need for a comprehensive body of normal value of peak expiratory flow rate (PEFR) among tribal children, the present study was undertaken. Two hundred forty-two children belonging to two scheduled tribes 'Soliga' and 'Jenukurubas' were studied, their PEFR was recorded and correlated with anthropometric data. There was a significant positive correlation between PEFR and age, height, weight, body surface area, arm span and chest expansion in the study group. This was compared with other Indian and Western studies and a nomogram to predict PEFR from height was constructed.

Effect of 2-5 years of tobacco smoking on ventilatory function tests.

Smoking is a pernicious scourge of the world today. There is paucity of literature on the effect of acute smoking on ventilatory functions. The present work is undertaken to study the effect of 2-5 years of tobacco smoking on ventilatory functions. The study group consisted of 30 male, young, healthy subjects, free from cardiopulmonary diseases and with history of smoking of 2-5 years duration, on an average of 10 cigarettes per day. The control group consisted of 30 age-and sex-matched healthy individuals who had naver smoked tobacco. The ventilatory function tests were carried out using electronic spriolyser. There was a significant lowering of the following parameters in smokers: Vital capacity (VC), inspiratory reserve volume (IRV), inspiratory capacity (IC), forced vital capacity (FVC), forced expiratory volume at the end of first second (FEV1), maximum midexpiratory flow (MMEF), peak expiratory flow (PEF), midexpiratory flow75 (MEF75), maximum voluntary ventilation (MVV). This study shows that 2-5 years of tobacco smoking leads to a definite tendency to narrowing of both the large and the small airways.