Abstract: A spirometry system operable to measure airflow through an air passage defined by a mouthpiece including one or more contact sensors configured to generate at least one mouth contact signal indicative of user mouth contact with the proximal portion of the mouthpiece. The spirometry system can further include an airflow sensor configured to generate an airflow signal corresponding to airflow within the air passage, and processor circuitry communicatively coupled to the one or more contact sensors and to the airflow sensor. The processor circuitry can be configured to determine an indication of an amount of user mouth contact for use with a measurement of airflow by the processor circuitry.