This paper presents a novel loudspeaker concept that realizes both conventional and directional loudspeaker functions using a single transducer component. The transducer component works in such a way that its low frequency characteristics satisfy the requirements of the conventional loudspeaker, while one of its natural frequencies is located in the ultrasonic range. When the input exciting signal is a conventional audio signal, the transducer can produce conventional audible waves. When the input signal is an ultrasonic signal modulated by audible signal, it can produce the ultrasound by working near the specific natural frequency of the transducer component. Then the nonlinear interaction of ultrasound in air can produce directional audible sound. In this study, a demonstrator is built for testing the feasibility of the concept. The experiment results indicate that this concept is feasible even though the performance of this demonstrator should be further improved and optimized.
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