RESUMEN
Background: The noise is considered as a factor of environmental stress, causing a wide range of health effects such as acoustic, cardiovascular, nervous and endocrine systems
Purpose: The present study was conducted to examine the affects of repeated exposure to noise on the peripheral auditory system, adrenal gland and heart tissue
Method: The White strain rats "Wistar" were exposed to chronic and repetitive exposure noise at two different intensity levels of 70 and 85dB [A]. The noise level was generated by the Audacity® software to an octave-band noise [8616 kHz]. The sound exposure duration was 6 hr/day, 5 days per week for 3 months. Quantitative and qualitative investigations were performed by using electron microscopy. The ganglion neuron counting was examined via light microscopy
Results: The results show that exposure to sound intensities 70 and 85 dB [A] for long periods, lead to changes in the morphological structure of the cochlea [inner ear], adrenal cortex and cardiac tissue which involve cell disruption which over time can lead to pathological effects
Conclusion: This study provides morphological evidence that repetitive exposure noise at moderate sound levels to 70 and 85 dB [A] induces changes in the peripheral auditory system, the adrenal cortex and heart tissue