Breath Sound Acquisition in Different Environments

Breathing is one of the vital functions of a human. This is why the monitoring of breathing represents an important tool for diagnosing a medical condition in a patient, that is, for assessing health status. Apart from medical diagnostics, breath monitoring can be used for other purposes such as managing stress, optimizing sports performance, security applications, or human-computer interaction. Breath detection employs diverse sensors and approaches. The initial step in this process involves acquiring breath sound. This paper explores the potential for acquiring breath sound using several types of microphones in different environments. To this end, four microphones of varying types (digital MEMS, electret, studio condenser, and smartphone microphone) are utilized. Acquisition is conducted in two distinct environments or scenarios: with the microphone in the air in close proximity to the nose and mouth, and with the microphone in a military gas mask. The recorded signals are subsequently analyzed in both the time and spectral domains.