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.
