Hearing System Sidetone Signal Quality Control

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Solution Overview

Problem

Hearing systems with miniature devices face challenges in providing natural voice feedback and ambient sound awareness during telephone calls, leading to unpleasant sound artefacts like comb-filter effects or echoes due to delayed wireless transmission of sidetone signals.

Innovation Solution

The method involves picking up primary and secondary sidetone signals and adjusting their amplifications in an opposing manner to combine them effectively, improving sidetone signal quality by using directional sound processing and wireless communication links to manage signal latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wireless transmission is used to transmit the primary sidetone signal from the telephone to the hearing device, then the user can receive voice feedback from the remote participant, but sound artefacts like comb-filter effects or echoes occur due to signal delay

Engineering Contradiction:
Improvevoice feedback qualityVSAvoidsound artefacts
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by processing and adjusting the primary sidetone signal before transmission. The signal is picked up by the telephone microphone, processed through signal processing circuits, and adjusted for amplification levels before being transmitted wirelessly to the hearing device. This preliminary processing reduces the occurrence of sound artefacts like comb-filter effects and echoes during wireless transmission.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the hearing device microphone picks up ambient sounds for the secondary sidetone signal, then the user remains aware of surroundings, but the sidetone signal quality deteriorates in noisy environments

Engineering Contradiction:
Improveambient sound awarenessVSAvoidsidetone signal quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies dynamics by making the amplification levels of the primary and secondary sidetone signals adjustable and adaptable. The system can dynamically adjust the balance between the primary sidetone signal (from telephone microphone) and the secondary sidetone signal (from hearing device microphone) based on environmental conditions. This allows the user to maintain ambient sound awareness when needed while ensuring high sidetone signal quality in noisy environments by adjusting the relative amplification levels.

Inventive Principle:
Principle #15Dynamics

3Reliability

If both primary and secondary sidetone signals are transmitted and combined, then comprehensive voice feedback is provided, but the system complexity increases due to multiple amplification adjustments

Engineering Contradiction:
Improvevoice feedback completenessVSAvoidamplification control system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies feedback by implementing a control system that monitors the combined sidetone signal quality and automatically adjusts the amplification levels of both primary and secondary signals. The system provides comprehensive voice feedback by combining both signal sources while using feedback mechanisms to maintain optimal balance, thereby reducing the perceived complexity for the user. The control unit automatically manages the amplification adjustments based on signal quality metrics.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3072314B1A method of operating a hearing system for conducting telephone calls and a corresponding hearing system
Publication Date: 2019.05.22 SONOVA AG
  • EP3072314B1 patent drawingFigure 1~2
  • EP3072314B1 patent drawingFigure 3
  • EP3072314B1 patent drawingFigure 4~5

AI summary

The present invention proposes a method of operating a hearing system for conducting telephone calls as well as a hearing system capable of performing the proposed method. The hearing system comprises a communication device (4) with a communication device microphone (3') for picking up a first sound signal and providing a primary sidetone signal. The hearing system further comprises a hearing device (2) with a hearing device microphone (3) for picking up a second sound signal and providing a secondary sidetone signal. A first amplification is applied to the primary sidetone signal and a second amplification is applied to the secondary sidetone signal. Adjusting of the first amplification is dependent on adjusting of the second amplification, or alternatively, adjusting of the second amplification is dependent on adjusting of the first amplification. The primary and secondary sidetone signals are then combined and subsequently output by a hearing device loudspeaker (14).