In the conventional group, the antral cross-section was monitored through ultrasonography to determine whether the tube entered the antrum based on the tube sound shadow
. Subsequently, the tube was advanced to a depth of 105-110 cm.
A surface that obstructs a source of sound may mediate, reflect, and absorb the acoustic signal, resulting in an acoustic or sound shadow
(Gordon & Rosenblum, 2004).
Synoground, for example, can tell when he's within 8 to 10 feet of a building because the structure alters sound, creating what Synoground refers to as a "sound shadow
" around it.
But Prof Wright's system is the first to produce a personal 'sound shadow
' that extends over a wide cone-shaped area in which everything but the unwanted noise can be heard - both indoors and outdoors.
Prof Wright's system, described in the magazine New Scientist today, is the first to produce a personal "sound shadow
" that extends over a wide cone-shaped area in which everything but the unwanted noise can be heard.