Shared Stereo Headphones With DSP Speech Ducking and Echo Control

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Solution Overview

Problem

Conventional headphones cannot be shared between users without disrupting the stereo nature of audio signals, leading to a compromised listening experience and isolation of users from each other.

Innovation Solution

A system utilizing digital signal processors (DSPs) to allow two users to listen to the same stereo audio source while maintaining verbal communication, by ducking audio signals in response to speech and canceling echoing caused by microphone feedback, allowing users to share audio and speech signals without interfering with each other's experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional headphones are shared between users by splitting left and right channels, then multiple users can listen to audio simultaneously, but the stereo nature of audio is disrupted and each user only experiences half of the intended audio

Engineering Contradiction:
Improveheadphone sharing capabilityVSAvoidstereo audio experience
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The system segments the audio distribution by providing separate stereo signals to each user through individual headphones or earbuds, rather than splitting channels between users. Each user receives complete stereo audio through their own left and right earpieces, preserving the full stereo experience for both users simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system creates separate copies of the stereo audio signal for each user. The audio source generates duplicate stereo signals that are independently transmitted to each user's headphones, ensuring both users receive identical complete stereo audio rather than split channels.

Inventive Principle:
Principle #26Copying

2Adaptability or versatility

If users wear headphones to share audio experience, then they can listen to audio together, but they cannot communicate with each other because both ears are covered

Engineering Contradiction:
Improveaudio sharing capabilityVSAvoidverbal communication capability
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The headphones are designed with multi-functionality, serving both audio listening and communication purposes. Each headphone includes integrated microphones and speakers that enable users to listen to audio while simultaneously engaging in verbal communication with each other without removing the headphones.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system introduces an intermediary communication channel through the headphones themselves. The integrated microphones and speakers act as intermediaries that transmit speech between users while the audio signal continues to play, allowing communication without compromising the audio sharing experience.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If audio signals are transmitted to multiple users simultaneously, then users can share the listening experience, but echoing and interference occur due to microphone feedback

Engineering Contradiction:
Improvemulti-user audio transmissionVSAvoidecho and interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The system implements feedback control mechanisms that detect echo and interference caused by microphone signals interacting with audio output. The system actively manages this feedback loop to suppress unwanted echoing while maintaining clear communication between users.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system converts the potentially harmful echo and feedback into beneficial information by using the feedback signals to adjust and optimize the audio transmission. The echo paths are analyzed and utilized to improve signal quality and reduce interference through adaptive processing.

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

Data Source

PatentEP3262851B1Techniques for sharing stereo sound between multiple users
Publication Date: 2024.04.24 HARMAN INT IND INC
  • EP3262851B1 patent drawingFigure 1
  • EP3262851B1 patent drawingFigure 2
  • EP3262851B1 patent drawingFigure 3

AI summary

A first digital signal processor (DSP) associated with a first user outputs audio to the first user via first headphones, and captures speech from the first user via a first microphone. Similarly, a second DSP associated with a second user outputs audio to the second user via second headphones, and captures speech from the second user via a second microphone. The first DSP is coupled to the second DSP in order to allow the first and second users to share music and communicate with one another. The first user may speak into the first microphone, and the first and second DSPs may then interoperate to output that speech to the second user without substantially disrupting audio output to the second user. Each of the first and second users may also select between first and second audio sources that may be coupled to the first and second DSPs, respectively.