Frequency characteristics of air-structural and structural sound transmission in human lungs

摘要

From an independent sampling of data on luminal probing of the lungs of 20 people, based on an analysis of the phase characteristics of the coherency function of the signal with linear frequency modulation in a frequency band of 80-1000 Hz recorded above the trachea and different areas of the chest, the frequency selectivity of the structural and air-structural transmission variants has been revealed. It has been established that structural sound transmission on average is observed in a band from 100 to 280 Hz and air-structural propagation lies in the frequency range from 100 to 500-700 Hz. Over areas of the lungs characterized by the presence of aerated tissues (the apex and lower lobe), more frequently there is air-structural transmission, whereas in the vicinity of dense organs of the mediastinum (intercapsular region), on the contrary, structural propagation dominates.