摘要 |
The present invention is directed to a communication system wherein ultrasonic signals can be used as carriers to efficiently produce high fidelity, wide audio bandwidth sound. Exemplary embodiments rely on the airborne transport of an inaudible ultrasonic carrier directly into the ear canal of a user, such that the non-linearities within the ear itself can be exploited to demodulate the ultrasonic carrier without producing audible sounds at the input to the user's ear. The non-linearities of the ear itself, in conjunction with the human brain's perception of audible frequencies generated in response to ultrasonic stimulation, are relied upon to detect audio information. The ultrasound-to-audio-sound conversion in the confined volume of the inner ear appears to be constant pressure, as opposed to constant velocity, such that all frequencies of the audio bandwidth (including low frequency bass signals) are produced with comparable sound intensity.
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