Conference Audio System Directional Sound via Time Delay
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Solution Overview
Problem
In large conference rooms, existing conference audio systems fail to provide directivity to audio signals, making it difficult for listeners to localize the speaker due to the simultaneous reproduction of audio signals by all delegate loudspeakers, which results in a loss of directional sound atmosphere.
Innovation Solution
The conference audio system introduces a time delay to each delegate loudspeaker based on its distance from the active microphone or sound source, utilizing the Haas effect to create directional properties by varying the timing of audio signal arrival, thereby enhancing listener perception of the sound source's location.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If all delegate loudspeakers reproduce audio signals simultaneously, then the system is simple and easy to operate, but directivity is lost and listeners cannot localize the speaker in large rooms
Solution Approach 1:
The system pre-calculates and stores time delay values for each delegate loudspeaker based on its distance from the active microphone. When a speaker activates, the corresponding pre-computed delay is immediately applied, enabling directional sound without real-time complex calculations. This preliminary preparation resolves the contradiction by making the delay application as simple as simultaneous reproduction while achieving directivity.
2Measurement precision
If time delay is added to each delegate loudspeaker to create directivity, then speaker localization is improved, but system complexity increases
Solution Approach 1:
Each delegate loudspeaker receives a customized time delay value specific to its spatial position relative to the active microphone. Instead of a uniform system-wide delay, locally optimized delays are applied at each loudspeaker based on its individual distance measurement. This local customization achieves precise speaker localization while keeping each local node simple.
Solution Approach 2:
The system creates virtual acoustic images by delaying audio signals at different loudspeakers, effectively copying the natural acoustic propagation delays that would occur in the absence of electronic reinforcement. This copying of natural acoustic behavior achieves localization precision without requiring complex active control mechanisms.
3Reliability
If delegate units are connected by wiring, then connection reliability is high, but installation complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical wiring system with wireless communication between delegate units and the control means. Each delegate unit equipped with a microphone and loudspeaker can communicate audio signals and control data wirelessly, eliminating the need for physical cable connections while maintaining system reliability through digital communication protocols.
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 effectively adds directivity to the audio atmosphere with minimal additional technical equipment, allowing listeners to better identify the speaker's position even at greater distances by using individually adjusted time delays, maintaining the Haas effect's effectiveness even with varying sound levels.
Implementation Method 1
the delegate loudspeakers emit the audio signal with the individual time delay, the audio signal generated by the active delegate microphone
Implementation Method 2
The time delay is preferably in accordance with the 'Haas effect'. The Haas effect is also called the precedence effect and describes the human psychoacoustic phenomena of correctly identifying the direction of the sound source heard in both ears but arriving at different times.
Data Source
AI summary
Conference audio systems are widely known and are usually used in political or economic debates, at fairs and wherever a plurality of people discuss with each other supported by a microphone-amplifier-loudspeaker system. In known systems each delegate of a conference has a seat with a working table in which the microphone and the loudspeaker is integrated. A conference audio system is proposed comprising a plurality of delegate units (2), each delegate unit (2) having a delegate loudspeaker (5) and/or a delegate microphone (4), a control means (3, 15) for distributing at least one audio signal from at least one of the delegate microphones (4) or another sound source to a plurality of the delegate loudspeakers (5), the plurality of delegate loudspeakers (5) generating a common audio atmosphere, delay means (16) operable to add a time delay on the audio signal, whereby the time delay is dependent from the distance between the position of the delegate microphone (4) or sound source, respectively, generating the audio signal and the individual delegate loudspeaker (5) position.