An amplifier circuit for a parametric transducer and a related audio device

An audio device comprising:

• (i) a signal processor for processing an input signal into first and second signals with different phase-shifts;
• (ii) at least a pair of parametric transducers;
• and
• (iii) at least two pairs of output stages arranged to respectively receive the first and second signals for generating two pairs of amplified signals, which are respectively provided to the parametric transducers for generating corresponding ultrasonic signals with the phase-shifts,
• wherein the signal processor, and output stages collectively form an amplifier circuit;
• wherein the input, first and second signals are arranged with a substantially similar frequency to cause a switching frequency of the amplifier circuit to be matched to carrier frequencies of the parametric transducers;
• and
• wherein the parametric transducers are arranged to direct the ultrasonic signals towards a common area in the air to cause interaction of the ultrasonic signals within the area to obtain an audible audio signal.