Approach for partially preserving music in the presence of intelligible speech

• US 20170223451A1
• Filed: 03/31/2017
• Published: 08/03/2017
• Est. Priority Date: 06/09/2014
• Status: Active Grant

• Current Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Inventors: Kreifeldt, Richard Allen, Iyer, Ajay, Kirsch, James M.
• Granted Patent: US 10,368,164 B2
• Time in Patent Office: Days
• CPC Class Codes: G10L 21/02 Speech enhancement, e.g. noise reduction or echo cancellation reducing echo effects in line transmission systems H04B3/20; echo suppression in hands-free telephones H04M9/08
• CPC Class Codes: G10L 21/0364 for improving intelligibility
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10
• CPC Class Codes: G10L 25/84 for discriminating voice from noise
• CPC Class Codes: H03G 9/005 of digital or coded signals
• CPC Class Codes: H03G 9/025 frequency-dependent volume compression or expansion, e.g. multiple-band systems H03G9/10, H03G9/18 take precedence
• CPC Class Codes: H04R 1/1041 Mechanical or electronic switches, or control elements switches in general H01H
• CPC Class Codes: H04R 2420/01 Input selection or mixing for amplifiers or loudspeakers for hearing aids H04R25/43
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 2430/01 Aspects of volume control, not necessarily automatic, in sound systems
• CPC Class Codes: H04R 3/002 Damping circuit arrangements for transducers, e.g. motional feedback circuits
• 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 3/04 for correcting frequency response

Abstract

An audio processing system for a listening device includes an input device, a voice activity detector and a ratio-based attenuator. The input device is configured to receive a first audio signal emanating from an environment and including a signal of interest. The voice activity detector is configured to generate a control signal in response to the first audio signal. The ratio-based attenuator is configured to receive the control signal and determine whether the signal level of the first audio signal exceeds the signal level of an audio signal received from an audio playback device by at least a target difference. If so, then the audio level of the playback audio signal is maintained. Otherwise, the audio level of the playback audio signal is adjusted, where, at the adjusted value, the first signal level exceeds the playback signal level by at least the target difference.

Claims

1. An audio processing system, comprising:

an input device that receives a first audio signal;

a voice activity detector that;

receives a first control signal from a voice separator;

determines that a signal of interest is present in the first audio signal based on the first control signal exceeding a ducker threshold; and

generates a second control signal in response to the first audio signal; and

a ratio-based attenuator that;

receives the second control signal from the voice activity detector,

determines whether a first signal level associated with the first audio signal exceeds a second signal level associated with a second audio signal received from an audio playback device, and

if the first signal level exceeds the second signal, then maintains an audio level of the second audio signal, or

if the first signal level does not exceed the second signal level difference, then causes the audio level of the second audio signal to be adjusted from a first value to a second value.

2. The audio processing system of claim 1, further comprising a sound environment analyzer that performs one or more noise reduction operations on the first audio signal to remove a noise signal from the first audio signal.

3. The audio processing system of claim 1, further comprising the voice separator that:

applies a first bandpass filter to the first audio signal to generate a first filtered audio signal;

calculates a third signal level associated with the first filtered audio signal; and

generates the first control signal based on the third signal level.

4. The audio processing system of claim 3, further comprising an ambience separator that:

applies a second bandpass filter to the first audio signal to generate a second filtered audio signal;

calculates a fourth signal level associated with the second filtered audio signal; and

generates a third control signal based on the fourth signal level.

5. The audio processing system of claim 4, wherein the first bandpass filter and the second bandpass filter have the same frequency range.

6. The audio processing system of claim 4, wherein the voice activity detector further:

receives the third control signal from the ambience separator; and

determines that the signal of interest is present in the first audio signal based on the first control signal also exceeding the third control signal.

7. The audio processing system of claim 1, further comprising a first signal level detector that calculates the first signal level;

and a second signal level detector that calculates the second signal level.

8. The audio processing system of claim 1, further comprising an intelligent system monitor that:

determines that the signal of interest is no longer present in the first audio signal;

maintains the audio level of the second audio signal at the second level for a threshold duration of time; and

after the threshold duration of time has expired, causes the audio level of the second audio signal to increase to the first level.

9. The audio processing system of claim 1, further comprising attack/release logic that applies a first attack/release profile to the second audio signal when the signal of interest is present or removed and applies a second attack/release profile to the second audio signal when the presence of the signal of interest has been detected for a threshold duration of time.

10. The audio processing system of claim 1, wherein the ratio-based attenuator generates a third control signal that indicates an amount that the second audio level is to be adjusted, and includes a voltage controlled amplifier that attenuates the second audio signal based on the third control signal to generate a third audio signal.

11. The audio processing system of claim 10, further comprising a mixer that combines the first audio signal with the third audio signal to generate an output signal, and transmits the output signal to a speaker.

12. A computer-implemented method, comprising:

receiving a first audio signal emanating from an environment;

detecting that a signal of interest is present in the first audio signal based on a first control signal associated with the first audio signal exceeding a ducker threshold;

determining whether a first signal level associated with the first audio signal exceeds a second signal level associated with a second audio signal received from an audio playback device, and

if the first signal level exceeds the second signal level, then maintaining an audio level of the second audio signal, and

if the first signal level does not exceed the second signal level, then causing the audio level of the second audio signal to be adjusted from a first value to a second value.

13. The method of claim 12, further comprising:

applying a first bandpass filter to the first audio signal to generate a first filtered audio signal;

calculating a third signal level associated with the first filtered audio signal;

generating the first control signal based on the third signal level.

14. The method of claim 13, further comprising:

applying a second bandpass filter to the first audio signal to generate a second filtered audio signal;

calculating a fourth signal level associated with the second filtered audio signal;

generating a second control signal based on the first signal level.

15. The method of claim 14, further comprising determining that the signal of interest is present in the first audio signal based on the first control signal also exceeding the second control signal.

16. A non-transitory computer-readable storage medium including instructions that, when executed by a processor, cause the processor to perform the steps of:

receiving a first audio signal emanating from an environment;

detecting that a signal of interest is present in the first audio signal based on a first control signal associated with the first audio signal exceeding a ducker threshold;

determining whether a first signal level associated with the first audio signal exceeds a second signal level associated with a second audio signal received from an audio playback device, and

if the first signal level exceeds the second signal level, then maintaining an audio level of the second audio signal, and

if the first signal level does not exceed the second signal level, then causing the audio level of the second audio signal to be adjusted from a first value to a second value.