Speaker-Based Wind Noise Detection and Cancellation

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Solution Overview

Problem

Background acoustic noise, particularly wind noise, significantly affects the quality of audio signals in communication devices by masking or saturating the microphone, making it difficult to hear a speaker's voice and rendering devices inoperable in persistent noise conditions.

Innovation Solution

An audio processing system that repurposes a speaker as a microphone to detect and process wind noise, using a signal routing device to route the speaker output signal to a signal processor for filtering and combining with the microphone output to reduce wind noise, thereby improving the quality of the audio signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a sensitive microphone is used to capture audio signals, then the quality of audio signal is improved, but the microphone becomes susceptible to wind noise saturation

Engineering Contradiction:

Improveaudio signal qualityVSAvoidwind noise saturation

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a speaker as an intermediary device that captures wind noise and converts it to an electrical signal. This speaker-mediated approach allows the system to detect and process wind noise separately, preventing direct saturation of the primary microphone while maintaining audio signal quality.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a copy of the wind noise signal through the speaker, which then acts as a reference signal for processing. By copying the wind noise characteristics through the speaker output, the system can subtract or filter this copied noise from the original microphone signal, preventing saturation while preserving useful audio.

Inventive Principle:

Principle #26Copying

2Ease of operation

If the microphone is used to capture audio in windy environments, then telephony function is provided, but the speaker's voice becomes unintelligible due to background noise

Engineering Contradiction:

Improvetelephony functionVSAvoidspeaker's voice intelligibility

Core Design Contradiction:

Ease of operationVSLoss of information

Solution Approach 1:

The patent implements a feedback mechanism where the speaker output signal (containing wind noise) is fed back to the signal processor. This feedback loop enables real-time detection and cancellation of wind noise, allowing the system to maintain speaker voice intelligibility while continuing to provide telephony function in windy environments.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent converts the harmful wind noise captured by the speaker into a useful reference signal for noise cancellation. By utilizing the speaker's output (which contains wind noise) as a beneficial reference, the system can actively subtract this noise from the microphone signal, transforming the previously harmful noise into a tool for improving voice intelligibility.

Inventive Principle:

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

3Object-affected harmful factors

If wind noise is present in all immediate vicinity, then moving to a different location is the only solution, but this reduces convenience and usability

Engineering Contradiction:

Improvewind noise impactVSAvoiddevice usability

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent enables the device to self-correct for wind noise interference through signal processing. The system uses its own speaker and microphone to detect, process, and cancel wind noise without requiring user intervention to move locations. This self-service capability allows the device to maintain usability in previously unusable windy environments.

Inventive Principle:

Principle #25Self-service

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 reduces the impact of wind noise on audio systems, enhancing the intelligibility of the speaker's voice and preventing microphone saturation, even in environments with persistent wind noise, by utilizing the speaker's output to modify and improve the audio signal.

Implementation Method 1

a speaker to convert an electronic signal corresponding to the callee's received voice into an acoustic output

Methodology Applied

Scientific EffectElectroacoustic transduction:

Implementation Method 2

a microphone to convert a caller's voice into an electronic signal for processing

Methodology Applied

Scientific EffectAcoustic transduction:

Data Source

PatentEP2996352B1Audio system and method using a loudspeaker output signal for wind noise reduction

Publication Date: 2019.04.17 NXP BV

Figure 1
Figure 2

AI summary

An audio processing system and method are described. A microphone is arranged to generate a microphone output signal responsive to an acoustic input. A speaker is arranged to generate an acoustic output responsive to a speaker input signal and to generate a speaker output signal responsive to the acoustic input. A wind noise detector is arranged to receive and process the microphone output signal and/or the speaker output signal to detect wind noise. A signal processor is arranged to receive the microphone output signal and is configured to process the speaker output signal when wind noise has been detected. The microphone output signal is modified using a result of processing the speaker output signal to reduce the amount of wind noise in a processed audio signal output by the signal processor.