Vehicle Audio Privacy Control via Anti-Phase Masking

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Solution Overview

Problem

In vehicles, passengers can inadvertently hear a talker's private conversations, compromising their privacy due to incomplete sound control measures.

Innovation Solution

A vehicle system featuring speakers and a controller that generate a masking sound tuned to cancel the talker's voice, using microphones to receive voice information and adjust audio signals, and outputting background sounds based on location or preset criteria to maintain privacy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If speakers output sound in the vehicle, then passengers can hear background sounds and entertainment, but the talker's private conversation becomes audible to other passengers

Engineering Contradiction:

Improveaudio output functionalityVSAvoidprivacy leakage

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The system applies preliminary anti-action by generating an inverted sound wave (anti-phase noise) that cancels out the talker's voice before it can be heard by other passengers. The controller detects the talker's voice through the microphone and immediately outputs an inverted sound wave through the speaker, creating destructive interference that neutralizes the harmful sound propagation.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The system converts the harmful talker's voice into a beneficial cancellation signal. By inverting the phase of the detected voice and outputting it through the speaker, the system transforms the privacy-violating sound into a tool for its own elimination, creating a masking sound that protects privacy while allowing normal audio output functionality.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If the speaker outputs masking sound to cancel the talker's voice, then privacy is protected, but the clarity of background sounds and music is reduced

Engineering Contradiction:

Improvevoice leakage preventionVSAvoidaudio quality

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The system applies partial action by selectively canceling only the talker's voice frequency range while allowing background sounds and music to pass through. The controller processes the microphone input to identify and invert only the relevant voice components, applying the masking sound specifically to the frequency ranges where talker's voice is present, thereby maintaining overall audio quality while preventing privacy leakage.

Inventive Principle:

Principle #16Partial or excessive action

3Measurement precision

If the microphone sensitivity is increased to detect talker's voice accurately, then voice cancellation is more effective, but background noise and echo are amplified

Engineering Contradiction:

Improvevoice detection accuracyVSAvoidbackground noise and echo

Core Design Contradiction:

Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The system applies local quality by adjusting the microphone's sensitivity characteristics to be directionally selective. The microphone is positioned and configured to have higher sensitivity to sounds coming from the talker's direction while maintaining lower sensitivity to background noise and echo from other directions. This directional sensitivity allows accurate voice detection without amplifying unwanted sounds.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The system uses feedback by continuously monitoring the output speaker sound through the microphone and adjusting the voice cancellation in real-time. The controller processes the microphone input to distinguish between the talker's voice and reflected echo, applying adaptive filtering that cancels the direct voice while allowing reflected sounds to pass through, thereby preventing infinite echo amplification.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Effectively prevents other passengers from hearing the talker's voice by generating a masking sound that cancels the voice frequency, ensuring the talker's privacy while allowing background sounds to be outputted.

Implementation Method 1

generating a masking sound that can cancel the voice of the talker

Methodology Applied

Scientific EffectDestructive interference: Interference

Implementation Method 2

a microphone configured to receive the passenger's voice or the talker's voice

Methodology Applied

Scientific EffectMicrophone transduction:

Data Source

PatentUS11455980B2Vehicle and controlling method of vehicle

Publication Date: 2022.09.27 HYUNDAI MOTOR CO LTD

AI summary

A vehicle and a controlling method thereof are disclosed. The vehicle includes a first seat in which a talker is seated; a second seat in which a passenger is seated; a plurality of speakers provided in the first seat and the second seat; a microphone for receiving the voice of the passenger or the voice of the talker; and a controller configured to control the speaker to output a masking sound tuned based on the voice of the talker or the voice of the passenger.