The use of airborne ultrasonics for generating audible sound beams

摘要

A deveice known as a parametric array employs the nonlinearity of the air to create audible byproducts from inaudible ultrasound,resulting in an extremely directive,beam-like wide-band acoustical source.this source cna be projected about an area much like a spotlight,and creates an actual spatialized sound distant from the transducer.A basic theoretical analysis of the airborne parametric array is outlined and verified experimentally,and future channenges are discussed.