Techniques of Recording Respiratory Sounds

Sounds recorded over the chest wall represent complex waveforms associated with respiratory, cardiovascular, and muscular events. Recording and analysis of signals associated with respiratory system operation require a system which considers the dynamic and distributive nature of a sound source. An investigation of these acoustic events and the determination of basic characteristics of respiratory sounds, such as distribution of sound intensity over specific frequency bands correlated with other physiological variables, such as respiratory airflow and volume, may provide a quantitative assessment of pathophysiological conditions. The developed system provides an objective, calibrated recording, the storage of respiratory sounds, and corresponding respiratory parameters. System design, engineering and clinical aspects of respiratory sounds, recording, and analysis are discussed.