I know that most of us are able to hear sound, but to “see” sound? Unless you check out a printout sonic waves that have been visualized by a computer, here is a different way of doing it. Using wireless power transmission that relies on sound, the Hirose-Tanikawa Group from the University of Tokyo have managed to make sound beam routes visible to the masses. This is achieved thanks to a parametric speaker that will create a narrow sound beam using ultrasound. All sound from the speaker will be converted to electric power, where it will subsequently be used to light up LEDs.
Since the speaker is already commercially available, part of the work is already completed without having to spend time to research that. What needs to be done, however, is to design the circuit in order to convert the sound from the speaker to electric power. This particular circuit does not contain any batteries, but will comprise of just the microphone and the board. Output power has been rated at 10 mW at 50 cm, and 1 mW at 5 meters, allowing it to deliver enough juice to light up an LED 5 metres away.