Parametric in-ear impedance matching device
View Patent ↗An ultrasonic audio transducer system includes an ultrasonic speaker. The ultrasonic speaker may be an electrostatic emitter, a piezoelectric emitter (single crystal or stack), a piezoelectric film emitter, or any other emitter capable of emitting ultrasound. The ultrasonic speaker is configured to be coupled (via a wired or wireless connection) to an audio modulated ultrasonic carrier signal from an amplifier, wherein upon application of the audio modulated ultrasonic carrier signal, the ultrasonic speaker is configured to launch a pressure-wave representation of the audio modulated ultrasonic carrier signal into the air. Additionally, the ultrasonic speaker is implemented with an impedance matching element or optimized for matching the response within a user's ear canal.
1. An ultrasonic transducer system, comprising:
an ultrasonic emitter comprising at least one ultrasound transmitting layer coupled to a signal line carrying an audio modulated ultrasonic carrier signal, wherein upon application of the audio modulated ultrasonic carrier signal, the at least one ultrasound transmitting layer launches a pressure-wave representation of the audio modulated ultrasonic carrier signal into an ear canal of a user; and
an impedance matching element disposed on the ultrasonic emitter for substantially matching impedance within the ear canal to impedance of the ultrasonic emitter, the ultrasonic emitter further receiving ultrasound reflected from an ear drum of the user as a result of the launching of the audio modulated ultrasonic carrier signal into the ear canal, the reflected ultrasound being convertible into reusable electrical energy for use by the ultrasonic transducer system.
2. The ultrasonic transducer system of claim 1 , further comprising an amplifier for amplifying the audio modulated ultrasonic carrier signal.
3. The ultrasonic transducer system of claim 1 , further comprising a driver circuit for driving the ultrasonic emitter using the audio modulated ultrasonic carrier signal from the amplifier.
4. The ultrasonic transducer system of claim 1 , further comprising a signal processing circuit for at least one of equalizing, compressing, and filtering an audio signal used in modulation of the audio modulated ultrasonic carrier signal.
5. The ultrasonic transducer system of claim 1 , wherein the ultrasonic emitter comprises an electrostatic ultrasonic emitter.
6. The ultrasonic transducer system of claim 1 , wherein the ultrasonic emitter comprises a piezoelectric film ultrasonic emitter.
7. The ultrasonic transducer system of claim 1 , wherein the ultrasonic emitter comprises a piezoelectric stack ultrasonic emitter.
8. The ultrasonic transducer system of claim 1 , wherein the ultrasonic emitter comprises a piezoelectric crystal.
9. The ultrasonic transducer system of claim 1 , further comprising one of a wired battery power source and a wireless battery power source.
10. The ultrasonic transducer system of claim 1 , further comprising an enclosure encapsulating the ultrasonic emitter and the impedance matching element.
11. The ultrasonic transducer system of claim 1 , wherein the impedance matching element comprises a cone, and wherein at least one of a shape, size, wall thickness, and conical angle of the cone are adjusted commensurate with impedance within the ear canal.
12. The ultrasonic transducer system of claim 1 , wherein an ultrasonic carrier frequency of the audio modulated ultrasonic carrier signal is tuned in accordance with ultrasound reflected from an ear drum of the user as a result of the launching of the audio modulated ultrasonic carrier signal into the ear canal such that the ear canal is made to resonate with a standing wave at the ultrasonic carrier frequency.
13. The ultrasonic transducer system of claim 1 , wherein the single line comprises a wired signal line or a wireless signal connection.
14. An ultrasonic transducer system, comprising:
an amplifier;
an earpiece housing; and
an ultrasonic emitter mounted in the earpiece housing and comprising:
at least one ultrasound transmitting layer coupled to at least one signal line for launching a pressure-wave representation of an audio modulated ultrasonic carrier signal amplified by the amplifier into an ear of a user; and
an impedance matching element disposed on the at least one audio transmitting layer to substantially match an impedance within or relative to the ear canal to an impedance of the ultrasonic emitter, the ultrasonic emitter further receiving ultrasound reflected from an ear drum of the user as a result of the launching of the audio modulated ultrasonic carrier signal into the ear canal, the reflected ultrasound being converted into reusable electrical energy for use by the ultrasonic transducer system.
15. The ultrasonic transducer system of claim 14 , further comprising a signal processing module for equalizing, compressing, and filtering audio signals from an audio source and modulating the audio signals onto respective ultrasonic carriers to generate the audio modulated ultrasonic carrier signal.
16. The ultrasonic transducer system of claim 14 , further comprising a driver circuit for driving the ultrasonic emitter using the audio modulated ultrasonic carrier signal from the amplifier.
17. The ultrasonic transducer system of claim 14 , wherein the ultrasonic emitter comprises an electrostatic ultrasonic emitter.
18. The ultrasonic transducer system of claim 14 , wherein the ultrasonic emitter comprises a piezoelectric film ultrasonic emitter.
19. The ultrasonic transducer system of claim 14 , wherein the ultrasonic emitter comprises a piezoelectric crystal.
20. The ultrasonic transducer system of claim 14 , wherein the ultrasonic emitter comprises a piezoelectric stack ultrasonic emitter.
21. The ultrasonic transducer system of claim 14 , further comprising one of a wired battery power source and a wireless battery power source.
22. The ultrasonic transducer system of claim 14 , wherein the earpiece housing is configured to rest within the ear canal, the impedance within the ear canal being measured from a reference plane relative to a location at which the earpiece housing rests within the ear canal.
23. The ultrasonic transducer system of claim 14 , wherein the impedance matching element comprises one of an conical element, an aerogel element, or a foam element.
24. An ultrasonic transducer system, comprising:
an amplifier;
an earpiece housing;
and an ultrasonic emitter mounted in the earpiece housing, the ultrasonic emitter comprising:
at least one ultrasound transmitting layer coupled to at least one of a pair of signal lines for launching a pressure-wave representation of an audio modulated ultrasonic carrier signal amplified by the amplifier into an ear canal of a user, wherein the at least one ultrasound transmitting layer is configured to substantially match an impedance within the ear canal to an impedance of the ultrasonic emitter, wherein an ultrasonic carrier frequency of the audio modulated ultrasonic carrier signal is tuned in accordance with ultrasound reflected from an ear drum of the user as a result of the launching of the audio modulated ultrasonic carrier signal into the ear canal such that the ear canal is made to resonate with a standing wave at the ultrasonic carrier frequency;
at least one signal processing module for equalizing, compressing, and filtering an audio signal from an audio source and modulating the audio signal onto an ultrasonic carrier to generate the audio modulated ultrasonic carrier signal; and
a driver circuit for driving the ultrasonic emitter using the audio modulated ultrasonic carrier signal from the amplifier.
25. The ultrasonic transducer system of claim 24 , wherein the at least one audio transmitting layer is configured with respect to at least one of thickness and curvature to substantially match the impedance within the ear canal.