They furnish a point of impingement in articulation, and play their part in sympathetic resonance.
"Resonance in Singing and Speaking"
Thomas Fillebrown
After her first burst of disappointment Joan began to take the mishap as she had taken Tess's original trouble, as she would have taken a wet holiday or failure in the potato-crop; as a thing which had come upon them irrespective of desert or folly; a chance external impingement to be borne with; not a lesson.
"Tess of the d'Urbervilles A Pure Woman"
Thomas Hardy
The instrument is so sensitive that with a delicate galvanometer it will show the impingement of the heat from a person's hand thirty feet away.
"Edison, His Life and Inventions"
Frank Lewis Dyer and Thomas Commerford Martin