Abstract: Embodiments of the present invention are directed a system using a microphone and a mobile computer device comprising a transducer through which a user is to exhale or inhale; the transducer is configured and operable to convert the spirometric flow rate into an audible signal having an audio frequency responsive to the spirometric flow rate, wherein the transducer comprises a rotor including a plurality of rotor blades configured to rotate the rotor responsive to a spirometric flow; wherein the microphone is external to the transducer and is adapted to detect the audible signal having the audio frequency and to convert the audible signal to a corresponding electrical signal having the audio frequency.