Standing wave
DEFINITION
A vibration state where sound waves travelling within the instrument and reflected at each end combine so that at certain positions they cancel to create a pressure node (q.v.), while at others they add to create a pressure antinode (q.v.). A sustained sound on a brass instrument requires standing waves<br><br>An acoustic signal between two reflective surfaces with a distance that is an even multiple of one-half of the wavelength of the signal's frequency.