Impact Of Airflow Rate On Amplitude And Regional Distribution Of Normal Lung Sounds

In computerized lung sound research, the usage of a pneumotachograph, defining the phase of respiration and airflow velocity, is essential. To obviate its need, the influence of airflow rate on the characteristics of lung sounds is of great interest. Therefore, we investigate its effect on amplitude and regional distribution of normal lung sounds. We record lung sounds on the posterior chest of four lung-healthy male subjects in supine position with a 16-channel lung sound recording device at different airflow rates. We use acoustic thoracic images to discuss the influence of airflow rate on the regional distribution. At each airflow rate, we observe louder lung sounds over the left hemithorax and a constant regional distribution above an airflow rate of 0.7 l/s. Furthermore, we observe a linear relationship between the airflow rate and the amplitude of lung sounds.