Evaluation of the impact of a special sound signal on the functional state of the hearing organ (experimental study)

Abstract

   Introduction. The integration of special acoustic means into the safety system makes it relevant to conduct biomedical research to evaluate the impact of their effects on the hearing organs.   Objective. To study the characteristics of a special sound signal and its effect on the hearing organ of an experimental biological model.   Materials and methods. The study was conducted on 6 males (12 ears) guinea pigs (Cavia porcellus) weighing 200–250 grams at the age of 4 weeks. A set of special audio equipment was used to generate an acoustic signal. The study was conducted in a room with an area of about 47 m2. The time of a single exposure to experimental animals was 3 minutes at a sound level of 127–128 dBA. Before exposure and at different times after exposure (after 24 and 72 hours), the otoscopic picture was evaluated, a Preyer’s reflex and distortion-product otoacoustic emissions (DPOAEs) was carried out.   Results. The special sound signal was characterized by distinct frequency components and can be attributed to tonal noises. After acoustic exposure to a special sound signal, a normal otoscopic picture was observed in experimental animals. Restoration of the Preyer’s reflex occurred 24 hours after exposure. The restoration of the DPOAEs to background values at frequencies from 1.5 to 3.3 kHz occurred 24 hours after acoustic exposure, at a frequency of 4.2 kHz there was a significant tendency to recovery.   Conclusions. With a short-term (within three minutes) single exposure to a special sound signal with a sound level of 127 to 128 dBA on biological models (guinea pigs), no pathology of the hearing organ was detected. Given the greater resistance of humans to acoustic effects, compared to guinea pigs, this can equally be extended to humans.