Method and Apparatus for In-Ear Canal Sound Suppression

• US 20090147966A1
• Filed: 10/03/2008
• Published: 06/11/2009
• Est. Priority Date: 05/04/2007
• Status: Active Grant

• Current Assignee: Staton Techiya, LLC
• Original Assignee: Personics Holdings, Inc.
• Inventors: McIntosh, Jason, Boillot, Marc, Usher, John, Goldstein, Steven
• Granted Patent: US 9,191,740 B2
• Time in Patent Office: Days
• US Class Current: 381/71.110
• CPC Class Codes: H04M 3/568 audio processing specific to telephonic conferencing, e.g. spatial distribution, mixing of participants echo suppression in two-way loud-speaking telephone systems H04M9/02; sound field processing per se H04S7/30
• CPC Class Codes: H04M 9/08 Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
• CPC Class Codes: H04R 1/1016 Earpieces of the intra-aural type
• CPC Class Codes: H04R 2460/01 Hearing devices using active noise cancellation
• CPC Class Codes: H04R 2460/05 Electronic compensation of the occlusion effect
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 3/02 for preventing acoustic reaction , i.e. acoustic oscillatory feedback specially adapted for hearing aids H04R25/453

Abstract

An earpiece (100) and acoustic management module (300) for in-ear canal suppression control suitable is provided. A method for suppressing signals for a conference call, a vehicle, and a general communication event is also provided. The earpiece can include an Ambient Sound Microphone (111) to capture ambient sound, an Ear Canal Receiver (125) to deliver audio content to an ear canal, an Ear Canal Microphone (123) configured to capture internal sound, and a processor (121) to generate a voice activity level (622) and suppress an echo, spoken voice, and media content in the electronic internal signal, and mix an electronic ambient signal with an electronic internal signal in a ratio dependent on the voice activity level and a background noise level to produce a mixed signal (323) that is delivered to the ear canal (131).

Claims

1. A method of listening to music or other media content during a full duplex communication event, the method comprising the steps of:

delivering audio content to an ear canal of a first user by way of an Ear Canal Receiver (ECR) to produce an acoustic audio content where the audio content includes music or other media content;

capturing in the ear canal of the first user by way of an Ear Canal Microphone (ECM) an electronic signal comprising the acoustic audio content and a spoken voice of the first user in the presence of the audio content delivered to the ear canal;

suppressing the audio content in the electronic signal while preserving the spoken voice to produce a modified electronic signal; and

sending the modified electronic signal to at least one other user so that the audio content is sufficiently inaudible and the spoken voice is audible during the full duplex communication.

2. The method of claim 1 where the step of suppressing the audio content includes the steps of:

generating a voice activity level of the spoken voice of the first user in the presence of the audio content delivered to the ear canal; and

suppressing the audio content in the electronic signal to produce the modified electronic signal when the voice activity level is above a first predetermined threshold.

3. The method of claim 2 further including a step of adapting a first set of filter coefficients of a Least Mean Squares (LMS) filter to model an inner ear-canal microphone transfer function (ECTF) of the first user.

4. The method of claim 3 further including the steps of:

monitoring a voice activity level of the modified electronic signal; and

freezing an adaptation of the first set of filter coefficients for the modified electronic signal if the voice activity level is above the first predetermined threshold.

5. The method of claim 4, further including the steps of:

adapting a second set of filter coefficients for a replica of the LMS filter; and

substituting the second set of filter coefficients for the first set of filter coefficients when the voice activity level is below a second predetermined threshold.

6. The method of claim 5 further including suppressing the modified electronic signal when the voice activity level is below the second threshold to prevent the audio content from being sent when the first user voice activity level is low.

7. The method of claim 2 further including a step of determining voice activity level by an energy level characteristic and a frequency response characteristic of the spoken voice.

8. The method of claim 2 further including a step of controlling a mixing of the audio content and the spoken voice to the ear canal of the first user based on the voice activity level.

9. The method of claim 8 further including the steps of:

increasing a gain of an audio content signal as voice activity levels of the first user decrease, while decreasing a gain of a signal received from the at least one other user as voice activity levels of the first user decrease, or

decreasing the gain of the audio content signal as voice activity levels of the first user increase, while

increasing the gain of the signal received from the at least one other user as voice activity levels of the first user increase.

10. A method of conferencing, the method comprising the steps of:

initiating a conference call with two or more people;

selecting to suppress the voice communication of at least one person on the conference call where a modified electronic signal is generated with the selected at least one person voice communication being inaudible; and

sending the modified electronic signal to at least one other person on the conference call.

11. The method of claim 10 further including a step of generating the modified electronic signal by mixing the voice communication of all the participants of the conference call except the at least one voice communication selected to suppress.

12. The method of claim 10 further including the steps of:

initiating the conference call from a first communication device;

receiving each voice communication from participants on the conference call on a separate channel;

generating the modified electronic signal by suppressing the voice communication from a predetermined channel; and

sending the modified electronic signal to at least one channel other than the predetermined channel.

13. The method of claim 12 further including the steps of:

delivering audio content corresponding to the conference call to the ear canal of a user of the first communication device by way of a Ear Canal Receiver (ECR) to produce an acoustic audio content where the acoustic audio content includes the voice communication of the selected participant of the conference call to be suppressed;

capturing in the ear canal of the user of the first communication device the acoustic audio content by way of an Ear Canal Microphone where the ECM provides an electronic internal signal; and

suppressing the voice communication from the predetermined channel in the electronic internal signal thereby generating the modified electronic signal.

14. A method of listening to audio content comprising the steps of:

listening to audio content from a transducer coupled to a communication device;

engaging in a full duplex voice communication with the communication device where the voice communication and the audio content is output by the transducer; and

suppressing the audio content from a transmitted signal from the communication device such that participants receiving the transmitted signal hear a spoken voice of a user of the communication device but the audio content is inaudible.

15. The method of claim 14 where the step of listening to audio content includes a step of receiving music or media content.

16. The method of claim 14 further including sending a modified electronic signal having no information when a voice activity level of the spoken voice of the user of the communication device is below a first predetermined threshold whereby participants receiving the transmitted signal do not hear the audio content being played by the transducer coupled to the communication device.

17. The method of claim 14 further including the steps:

enabling an adaptive filter for providing a modified electronic signal for transmission by the communication device when a voice activity level of the spoken voice of the user of the communication device is above a second predetermined threshold;

providing the audio content as a reference signal for an adaptive filter;

providing a signal that includes the spoken voice of the user of the communication device and the audio content to the adaptive filter; and

substracting the audio content from the signal using the adaptive filter to generate the modified electronic signal.

18. A method of improving sound quality of a transmitted communication signal from a vehicle while an external loudspeaker of the vehicle is outputting an acoustic signal, the method comprising the steps of:

generating an electronic signal corresponding to an acoustic content in a cabin of the vehicle where the electronic signal includes a portion of the acoustic signal output by the external loudspeaker of the vehicle;

providing the electronic signal to a signal subtracting unit;

filtering a reference signal where the reference signal corresponds to the acoustic signal output by the external loudspeaker and where the filtered reference signal is provided to the signal subtracting unit; and

subtracting the reference signal from the electronic signal to generate a modified electronic signal where the acoustic signal output by the external loudspeaker is reduced in the modified electronic signal.

19. The method of claim 18 further including a step of transmitting the modified electronic signal via a communication system.

20. The method of claim 18 where the step of filtering includes a step of using a fixed FIR filter for filtering the reference signal.

21. The method of claim 18 where the step of filtering includes the steps of:

using an adaptive filter for filtering the reference signal; and

updating filter coefficients of the adaptive to approximate the acoustic impulse response between the external loudspeaker and a microphone in the cabin of the vehicle such the acoustic signal output by the external loudspeaker is inaudible in the modified electronic signal.

22. The method claim 18 further including a step of generating an emergency warning signal using the external loudspeaker to warn others in proximity to the vehicle that the vehicle is approaching.

23. The method of claim 18 further including a step of providing an algorithmically generated signal as the reference signal.

24. The method of claim 18 further including a step of retrieving the reference signal from memory.