Today, smart devices are ubiquitous as personal communications and entertainment devices. In most cases where the audio sound is played through the device’s speakerphone, the user has little privacy in that the sound can often be heard by bystanders. Compared to traditional audio-frequency loudspeakers that are currently employed in smart devices, parametric loudspeakers feature much better audio privacy, as the audio sound is highly directional and a private audio zone can be created. However, at present, parametric loudspeakers are only employed in outdoor applications and not portable smart devices due to their high power dissipation and subdued low frequency response. The Inventors have developed a technology that combines traditional and parametric loudspeakers to significantly reduce the device’s power dissipation while retaining the user’s privacy.