Which tool is frequently used to measure airflow when placed over the face?

The pneumotachograph is a specialized device designed to measure airflow, and it is often placed over the face to capture the air that enters and exits the respiratory system. This tool employs a transducer that generates voltage signals proportional to the airflow rate, allowing for real-time analysis of breathing patterns and speech production. The accurate measurement of airflow is crucial in speech science as it informs clinicians about respiratory function and can help assess various speech disorders.

In contrast, an endoscope is primarily used for visual examination of internal structures rather than for measuring airflow. A stroboscope is utilized to visualize vocal fold vibration, providing insights into phonatory function but does not measure airflow. An electroglottoscope is designed to monitor vocal fold contact and does not measure airflow either. Therefore, the pneumotachograph stands out as the appropriate tool for measuring airflow directly over the face during speech and respiratory assessments.