Which of the following is NOT a form of articulation measure?

Pneumotachographs are primarily used to measure airflow and respiratory function rather than directly assessing articulation, which relates to the movement and positioning of the articulators (like the tongue and lips) during speech. Electropalatography (EPG) and ultrasound are both direct methods for examining articulatory movements; EPG provides real-time feedback on tongue contact with the hard palate, while ultrasound visualizes tongue shape and movement. Intramuscular electromyography (EMG) measures muscle activation patterns of the muscles involved in articulation. Although pneumotachographs contribute valuable information regarding the airflow aspects of speech, they do not directly measure the articulation itself, making it the correct answer in this context.