American Technology Corp, the San Diego company with the revolutionary sound reproduction system that modulates thin air (CI No 2,964) has completed a $700,000 convertible debt financing to launch its new HyperSonic Sound system. The proprietary patent-pending technology is compatible with existing audio equipment and recording and broadcasting techniques yet none of the elements of traditional loudspeakers are employed in HyperSonic Sound, which uses the lowest harmonics of multiple ultrasonic frequencies to produce audible sound in air. The inaudible ultrasonic waves interact in space to produce audible sound – with ultra-wide dynamic range and ultra-wide frequency response. The cash will be used to move the technology from the laboratory and introduce it to audio equipment makers.