Investigation of changes in lung volume caused by high-intensity acoustic oscillations at the resonant frequency of the respiratory system

Abstract

This paper presents an experimentally determined dependency of an increase in the volume of the lungs of laboratory animals on the level of high-intensity low-frequency sound at the resonant frequency of their respiratory system. Experiments were conducted on 16 rabbits. A modified two-microphone technique was used for the measurement of the resonant frequency of the respiratory system in the frequency range from 5 Hz to 100 Hz for a step in frequency of 3 Hz. Having determined the resonant frequency, a tone signal was delivered to the lungs at this frequency with an adjustable sound amplitude from 120 to 138 dB. The measurement results indicate that the resonant frequencies of the respiratory system in rabbits decreased by an average of 13%, that corresponds to an increase in lung volume by 33% due to the opening of the alveolar oxygen reserve. The observed phenomenon relating to lung volume increase under the influence of a stimulating high-intensity sound signal at a resonant frequency can be used to enhance the effectiveness of bioacoustic stimulation of human lungs in order to increase the volume of the respiratory system.