Airflow Measurement

The volume of air passing through a constriction in a given unit of time is the flow rate or volume velocity. Speech is produced as a result of respiratory processes that generate a pressurized air stream. The air stream is regulated (valved) by laryngeal and supralaryngeal constrictions along the vocal tract. These aerodynamic processes are responsible for the acoustic and perceptual manifestation of all speech sounds. The measurement of airflow, therefore, is essential to describe normal speech production and to facilitate diagnosis and management of various disorders. This entry discusses the devices used to measurement air flow and how those measurements assist diagnosis.