Background Sound Removal Circuit for Mobile Privacy

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Solution Overview

Problem

Mobile phones and wireless devices often transmit background noise along with voice, potentially revealing the caller's location, which can compromise privacy and cause embarrassment if background sounds are detected during calls.

Innovation Solution

A system and method for background sound removal using multiple microphones, noise reduction circuits, and background cancellation circuits to generate audio signals that eliminate or replace residual background noise with desired background sounds, allowing users to maintain privacy during calls.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If the mobile phone microphone picks up voice combined with background sounds, then the transmission includes complete audio information, but the background sounds disclose location information and compromise privacy

Engineering Contradiction:

Improveaudio information completenessVSAvoidprivacy disclosure

Core Design Contradiction:

Loss of informationVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes background sound components from the mixed audio signal captured by the microphone. The background sound cancellation circuit specifically targets and eliminates background noise while preserving the foreground speech, thereby removing the privacy-disclosing elements while maintaining complete audio information transmission

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies asymmetric processing to different audio components: foreground speech is preserved with high fidelity while background sounds are suppressed or removed. This asymmetric treatment allows the system to maintain audio information completeness for speech while eliminating the harmful background noise that discloses location

Inventive Principle:

Principle #4Asymmetry

2Ease of operation

If the receiving party answers the call hoping no background sound will be heard, then the call can proceed, but background sounds during the call cause embarrassment

Engineering Contradiction:

Improvecall accessibilityVSAvoidembarrassment from background sound

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary background sound cancellation processing to the audio signal before transmission. By preemptively removing background sounds from the captured audio, the system prevents the embarrassment scenario from occurring in the first place, allowing the receiving party to answer calls confidently without worrying about unwanted background sounds being heard

Inventive Principle:

Principle #9Preliminary anti-action

3Object-affected harmful factors

If background sound removal is applied to maintain privacy, then location information is protected, but the audio signal quality may be affected

Engineering Contradiction:

Improveprivacy protectionVSAvoidaudio signal quality

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent applies local quality processing by treating foreground speech and background sound differently. The background sound cancellation circuit identifies and removes only the background noise components while preserving the speech signal integrity. This localized processing approach maintains high audio signal quality for the important speech content while achieving privacy protection through background sound removal

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS8768406B2Background sound removal for privacy and personalization use

Publication Date: 2014.07.01 DSP GROUP

AI summary

A system for background sound removal, the system may include: a noise reduction circuit arranged to apply a background sound reduction process on multiple samples of background sound and speech to provide first signals that comprise residual background sound; a background cancellation circuit arranged to remove the residual background sound from the first signals to provide second signals; and an output circuit arranged to output a mixture of the second signals and at least zero selected signals to a sound generating circuit that is arranged to output audio signals representative of the mixture.