Wide audio bandwidth transduction method and device
AssigneeGN ReSound North America Corporation
InventorJon C. Taenzer
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Abstract
The present invention is directed to a communication system wherein bone conducted ultrasonic signals are used as carriers to efficiently produce high fidelity, wide audio bandwidth sound. Exemplary embodiments rely on the use of modulation techniques which can achieve high fidelity audible sound, such as carrier plus single sideband (SSB) modulation. Known non-linearities within the ear itself can be exploited to demodulate the modulated 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 modulated ultrasonic stimulation, are relied upon to detect audio information.
Claims14
A communication device comprising:
- means for establishing an ultrasonic signal;
- means for modulating the ultrasonic signal with an audio signal using carrier plus single sideband modulation to produce a modulated ultrasonic signal at an output;
- and
- means for mounting the output in proximity to a human ear at a location where bone conduction will transport the modulated ultrasonic signal to a hearing mechanism associated with the ear which receives the audio signal as inaudible ultrasonic acoustic energy, wherein
- a difference between the frequency of the ultrasonic signal and the frequency of a single sideband is substantially equal to the frequency of the audio signal.
A method for communicating audible sound by a communication device, comprising the steps of:
- producing an ultrasonic signal;
- modulating the ultrasonic signal with an audio signal using carrier plus single sideband modulation to produce a modulated ultrasonic signal at an output, the ultrasonic signal being modulated so that a difference between the frequency of the ultrasonic signal and the frequency of a single sideband is substantially equal to the frequency of the audio signal;
- and
- directing the output in proximity to a human ear at a location where bone conduction will transport the modulated ultrasonic signal to a hearing mechanism associated with the human ear which receives the audio signal as inaudible ultrasonic acoustic energy.
Dependencies are inferred from the claim text.