Abstrakt
Sound as an oscillation of acoustic pressure is a manifestation that accompanies every mechanical movement in the Earth's atmosphere. Every change of mechanical system movement causes change in the progress of acoustic pressure and therefore recorded sound contains lot of information about movement of the specified system.
If the sound recording is processed and analyzed correctly, it is possible to detect changes in the system, analyse a source of these changes and thus find reason of change of movement. Method of system's disorder detection using analysis of generated sound is used also in medicine.
Auscultation - examination of the patient by listening - is often used method for lung function examination and the first used method for respiratory disease diagnosis (e.g. asthma). This method is performed using phonendoscope.
Unfortunately this method has its limitations, such as the low sensitivity of human ear and also congestion of recording due to unwanted noise. Therefore, both the detection of small changes in the respiratory sound and diseases diagnosis in their initial phase is quite difficult.
But early disease diagnosis is important because it means more efficiently treatment [1]. To obtain better and more reliable data on the patient's condition and for easier disease diagnosis using breath sound analysis, it is necessary to use sufficiently sensitive sensor to sound record, to process the record well and precisely.