Wayne Parham Messages: 18791 Registered: January 2001
Illuminati (33rd Degree)
Looks like there is a rivalry between American Technology Corporation and Holosonics for the same basic technology. Both use heterodyning interference between two ultrasonic wave carriers to develop an audible beat frequency in the audio band. The sound can be directed using beam steering techniques and since the carrier is a single high frequency that is modulated with audio, narrow-band techniques can be used. It is much easier to work with a single frequency or very narrow band than a wide band, particularly when doing beam steering. The main problem is that the ultrasonic carriers can be uncomfortable if high energies are used. Lower energy applications may have some promise.