Hybrid audio delivery system and method therefor

• US 20110103614A1
• Filed: 01/04/2011
• Published: 05/05/2011
• Est. Priority Date: 04/15/2003
• Status: Active Grant

• Current Assignee: IpVenture, Inc.
• Original Assignee: IpVenture, Inc.
• Inventors: Cheung, Kwok Wai, Tong, Peter P., Thomas, C. Douglass
• Granted Patent: US 8,849,185 B2
• Time in Patent Office: Days
• US Class Current: 381/94.1
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: H04R 1/403 loud-speakers
• CPC Class Codes: H04R 2201/023 Transducers incorporated in garment, rucksacks or the like
• CPC Class Codes: H04R 2217/03 Parametric transducers where sound is generated or captured by the acoustic demodulation of amplitude modulated ultrasonic waves
• CPC Class Codes: H04R 25/405 by combining a plurality of transducers
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407

Abstract

Methods and systems to produce audio output signals from audio input signals. In one embodiment, a first portion of the audio input signals can be pre-processed, with the output used to modulate ultrasonic carrier signals, thereby producing modulated ultrasonic signals. The modulated ultrasonic signals can be transformed into a first portion of the audio output signals, which is directional. Based on a second portion of the audio input signals, a standard audio speaker can output a second portion of the audio output signals. Another embodiment further produces distortion compensated signals based on the pre-processed signals. The distortion compensated signals can be subtracted from the second portion of the audio input signals to generate inputs for the standard audio speaker to output the second portion of the audio output signals. In yet another embodiment, noise can be added during pre-processing of the first portion of the audio input signals.

Claims

1. An audio system that produces audio output signals comprising:

a filter configured to separate audio input signals into low frequency signals and high frequency signals;

a pre-processor operatively connected to the filter to receive the high frequency signals from the filter and to perform predetermined preprocessing on the high frequency signals to produce pre-processed signals;

a modulator operatively connected to the pre-processor to modulate ultrasonic carrier signals by the pre-processed signals thereby producing modulated ultrasonic signals;

an ultrasonic speaker operatively connected to the modulator to receive the modulated ultrasonic signals and to output ultrasonic output signals which are transformed into high frequency portion of the audio output signals, which is directional; and

a standard audio speaker operatively connected to output low frequency portion of the audio output signals based on the low frequency signals.

2. An audio system as recited in claim 1 further comprising:

a distortion compensation unit operatively connected to the pre-processor to produce distortion compensated signals based on the pre-processed signals; and

a combiner operatively connected to the filter to modify the low frequency signals based on the distortion compensated signals to generate inputs for the standard audio speaker to output the low frequency portion of the audio output signals.

3. An audio system as recited in claim 2,

wherein the combiner subtracts the distortion compensated signals from the low frequency signals to generate the inputs for the standard audio speaker, and

wherein the distortion compensated signals are configured to compensate for at least some of the non-linear distortion in the high frequency portion of the audio output signals produced from the transformation of the ultrasonic output signals.

4. An audio system as recited in claim 2,

wherein the combiner subtracts the distortion compensated signals from the low frequency signals to generate the inputs for the standard audio speaker, and

wherein the distortion compensation unit is configured to substantially simulate non-linear distortion effect due to self-demodulation of ultrasonic signals in air.

5. A speaker arrangement as recited in claim 2,

wherein the combiner subtracts the distortion compensated signals from the low frequency signals to generate the inputs for the standard audio speaker, and

wherein the distortion compensation unit is configured to twice differentiate at least a portion of the pre-processed signals thereby producing distortion compensated signals.

6. An audio system as recited in claim 1 further comprising an audio signal generating device configured to generate the audio input signals.

7. An audio system as recited in claim 1, wherein said audio system is portable.

8. An audio system as recited in claim 1, wherein said audio system is wearable.

9. An audio system as recited in claim 1, wherein said audio system is part of a portable electronic device.

10. An audio system as recited in claim 1, wherein said audio system is integral with or coupled to a wireless communication device.

11. An audio system as recited in claim 10, wherein the wireless communication device is a mobile phone.

12. An audio system as recited in claim 3, wherein the pre-processor adds noise to the pre-processed signals.

13. An audio system to produce audio output signals comprising:

a pre-processor operatively connected to receive at least a portion of audio input signals and to perform predetermined preprocessing on the at least a portion of the audio input signals to produce pre-processed signals;

a distortion compensation unit operatively connected to the pre-processor to produce distortion compensated signals from the pre-processed signals;

a modulator operatively connected to the pre-processor to modulate ultrasonic carrier signals by the pre-processed signals thereby producing modulated ultrasonic signals;

an ultrasonic speaker operatively connected to the modulator to receive the modulated ultrasonic signals and to output ultrasonic output signals which are transformed into a first portion of the audio output signals, which is directional;

a standard audio speaker; and

a combiner operatively connected to the distortion compensation unit to subtract the distortion compensated signals from at least a portion of the audio input signals to generate inputs for the standard audio speaker to output a second portion of the audio output signals,

wherein the distortion compensated signals are configured to compensate for at least some of the non-linear distortion in the first portion of the audio output signals produced from the transformation of the ultrasonic output signals.

14. An audio system as recited in claim 13 further comprising a filter configured to separate the audio input signals into low frequency signals and high frequency signals,

wherein the pre-processor is operatively connected to the filter to receive the high frequency signals to produce the pre-processed signals, and

wherein the combiner is operatively connected to the filter to subtract the distortion compensated signals from the low frequency signals to generate inputs for the standard audio speaker to output the second portion of the audio output signals.

15. An audio system as recited in claim 13, wherein the pre-processor adds noise to the pre-processed signals.

16. An audio system as recited in claim 13 further comprising an audio signal generating device configured to generate the audio input signals.

17. An audio system as recited in claim 13, wherein said audio system is portable.

18. An audio system as recited in claim 17, wherein said audio system is integral with or coupled to a wireless communication device.

19. A method to produce audio output signals from audio input signals comprising:

processing at least a first portion of the audio input signals to produce pre-processed signals;

modulating ultrasonic carrier signals by the pre-processed signals thereby producing modulated ultrasonic signals;

outputting ultrasonic output signals by an ultrasonic speaker based on the modulated ultrasonic signals, the ultrasonic output signals being transformed into a first portion of the audio output signals, which is directional; and

outputting by a standard audio speaker a second portion of the audio output signals based on at least a second portion of the audio input signals.

20. A method to produce audio output signals as recited in claim 19 further comprising:

producing distortion compensated signals based on the pre-processed signals; and

subtracting the distortion compensated signals from the second portion of the audio input signals to generate inputs for the standard audio speaker to output the second portion of the audio output signals.