Audio Signal Path Validation via Acoustic Analysis

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Portable communication devices used by public safety personnel often suffer from component damage due to harsh environments and contaminants, leading to impaired communications, which existing self-tests cannot detect effectively, especially during active use.

Innovation Solution

A system and method that validate the operation of transducers and audio signal paths by analyzing audio signals generated from button presses and releases, using an audio power amplifier, analog-to-digital converter, and electronic processor to compare samples with reference signals, enabling detection of component failures and rerouting audio signals to maintain communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing self-tests are used to check components, then electronic continuity can be verified, but physical damage in components cannot be detected

Engineering Contradiction:

Improvecomponent failure detection capabilityVSAvoidcommunication reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent replaces electrical continuity testing with acoustic signal analysis. Instead of using electrical self-tests that only check circuit continuity, the system uses the transducer (speaker or microphone) to generate and capture acoustic signals, then analyzes these signals to detect physical damage. This substitution enables detection of physical damage that electrical tests cannot identify.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses the device's own transducer to generate test signals and capture the resulting acoustic responses. The transducer serves dual purposes: it is both the test stimulus generator and the response sensor, enabling self-diagnosis without requiring external testing equipment.

Inventive Principle:

Principle #25Self-service

2Measurement precision

If audio test signals are generated to test components, then component operation can be validated, but active communications are interrupted and users are annoyed

Engineering Contradiction:

Improvecomponent validation accuracyVSAvoidcommunication continuity

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

Instead of continuous or frequent test signals that would interrupt communication, the system performs acoustic validation periodically by analyzing natural acoustic events. The test is triggered by detecting button press acoustic signatures, allowing validation at appropriate intervals without continuously interrupting active communications.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system maintains continuous communication functionality while performing validation by using the same audio path for both communication and testing. Natural button press acoustic signals are utilized for validation purposes without requiring separate test signal generation, ensuring communication continuity.

Inventive Principle:

Principle #20Continuity of useful action

3Ease of manufacture

If electrical continuity tests are performed, then circuit connectivity can be confirmed, but physical damage such as shorted coils or damaged cones cannot be detected

Engineering Contradiction:

Improvetesting simplicityVSAvoidphysical damage detection

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent replaces simple electrical continuity testing with acoustic signal generation and analysis. By driving the transducer with electrical signals and capturing the resulting acoustic output (or vice versa for microphones), the system can detect physical damage conditions such as shorted voice coils, damaged diaphragms, or blocked acoustic ports that electrical continuity tests cannot identify.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This solution allows for the early detection of component failures, even during active use, and rerouting of audio signals to preserve communication, reducing the risk of interrupted communications and improving the reliability of portable communication devices in hazardous conditions.

Implementation Method 1

analyzing audio signals generated from button presses and releases, using an audio power amplifier, analog-to-digital converter

Methodology Applied

Scientific EffectTransducer conversion:

Implementation Method 2

using an audio power amplifier, analog-to-digital converter, and electronic processor to compare samples with reference signals

Methodology Applied

Scientific EffectAnalog-to-digital conversion:

Data Source

PatentUS20190349697A1Validating the operation of a transducer and an audio signal path

Publication Date: 2019.11.14 MOTOROLA SOLUTIONS INC

AI summary

Systems and methods for validating the operation of a transducer and an audio signal path to the transducer. An example method includes switching, with an audio switch, the audio signal path between an audio power amplifier and an analog-to-digital converter. The method includes routing an audio signal received from the transducer to the analog-to-digital converter when the audio power amplifier is not enabled. The method includes, upon receiving a button signal, processing, with an electronic processor, a digital version of the audio signal received from the analog-to-digital converter to generate a sample. The method includes comparing the sample to a reference audio sample. The method includes generating an alert when the sample does not match the reference audio sample.