Spectral Shaping of Detection Pulses for Inaudible Audio Accessory Identification

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Solution Overview

Problem

Existing methods for identifying audio accessories connected to electronic devices often introduce audible artifacts, such as clicks or noises, due to the difficulty in measuring impedance without causing disturbances, and may require repeated detection pulses to ensure accuracy, leading to undesirable delays and inaccuracies.

Innovation Solution

The method involves applying detection pulses that are shaped to be inaudible to humans by excluding energy components within the human audible frequency range, using low-frequency, low-amplitude, or high-frequency pulses, and spectrally shaping the pulses to minimize audible artifacts, allowing for accurate impedance measurement and identification of audio accessories without causing disturbances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional detection pulses are applied to measure impedance, then impedance measurement can be performed, but audible artifacts such as clicks or noises are introduced

Engineering Contradiction:
Improveimpedance measurement accuracyVSAvoidaudible artifacts
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies spectral shaping to modify the frequency domain parameters of detection pulses, redirecting energy from audible frequency ranges (20Hz-20kHz) to inaudible ranges (below 20Hz or above 20kHz). This parameter transformation allows impedance measurement to proceed while eliminating audible artifacts, as the modified pulses retain sufficient energy for accurate measurement without falling within the human audible range.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If repeated detection pulses are applied to ensure measurement accuracy, then measurement reliability improves, but detection delays increase

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoiddetection delay
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent employs a single-shot detection approach using spectrally shaped pulses that provide sufficient energy in one application to achieve reliable impedance measurement. This eliminates the need for repeated pulses, thereby reducing detection delays while maintaining measurement reliability through the optimized spectral distribution of the detection pulse energy.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If detection pulses with sufficient energy are applied to ensure accurate impedance measurement, then measurement accuracy improves, but audible disturbances increase

Engineering Contradiction:
Improveimpedance measurement accuracyVSAvoidaudible disturbances
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent transitions the detection pulse energy from the audible frequency dimension (20Hz-20kHz) to the inaudible frequency dimension (below 20Hz or above 20kHz) through spectral shaping. This dimensional shift in frequency space allows the pulses to maintain sufficient energy for accurate impedance measurement while existing outside the human audible range, thereby eliminating audible disturbances.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 approach enables reliable and fast identification of audio accessories while minimizing audible artifacts, improving user experience by reducing noise interference and ensuring accurate detection without prolonged delays.

Implementation Method 1

shaped to be inaudible to humans by excluding energy components within the human audible frequency range

Methodology Applied
Scientific EffectSpectral shaping:

Implementation Method 2

spectrally shaping the pulses to minimize audible artifacts

Methodology Applied
Scientific EffectFrequency domain transformation:

Data Source

PatentEP2763433B1Apparatus, systems and methods for inaudibly identifying an audio accessory using spectral shaping
Publication Date: 2017.04.05 BLACKBERRY LTD
  • EP2763433B1 patent drawingFigure 1
  • EP2763433B1 patent drawingFigure 2
  • EP2763433B1 patent drawingFigure 3

AI summary

A method for identifying an accessory coupled to an electronic device. The method includes applying at least one detection pulse to the audio accessory, each detection pulse being spectrally shaped to be generally inaudible to a human user, receiving at least one response signal corresponding to each detection pulse that is indicative of the impedance of the accessory, and based on the impedance, identifying the accessory.