Room Acoustics Enhancement via Dynamic Convolution and Switching

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Solution Overview

Problem

Event rooms often have unsatisfactory acoustic conditions for different types of events due to their natural acoustics being tailored for specific uses, and existing electroacoustic systems struggle to enhance acoustics without causing feedback or unnatural sound localization.

Innovation Solution

A method and sound system that record sound signals, convolve them with predetermined impulse response functions, and reproduce them through multiple loudspeakers with a switching mechanism to avoid feedback and create a natural, pleasant sound image, using a combination of microphones, convolution devices, and switching devices to distribute optimized sound signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electroacoustic systems are used to enhance room acoustics, then acoustic quality is improved, but feedback occurs causing sound discoloration

Engineering Contradiction:
Improveacoustic qualityVSAvoidfeedback
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by continuously varying the parameters of the electroacoustic system. The transfer functions are changed continuously and randomly over time, and the amplitude and time delays of individual signals are modulated. This dynamic variation prevents the establishment of stable feedback loops between microphones and loudspeakers, thereby eliminating feedback while maintaining acoustic enhancement.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements periodic action through the continuous and random variation of transfer functions and signal parameters over time. This periodic modulation of acoustic signals ensures that any potential feedback paths do not maintain consistent phase relationships, preventing feedback oscillation while preserving the beneficial acoustic effects.

Inventive Principle:
Principle #19Periodic action

2Object-generated harmful factors

If synthetically generated reverberation is used, then feedback is reduced, but the sound appears unnatural to listeners

Engineering Contradiction:
ImprovefeedbackVSAvoidnatural sound quality
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent uses copying by recording the natural impulse responses of the actual room acoustics and using these recorded responses as transfer functions in the electroacoustic system. This approach copies the authentic acoustic characteristics of the room, ensuring that the enhanced sound maintains natural quality while the controlled application prevents feedback.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The system applies parameter changes by continuously varying the amplitude, time delays, and transfer functions of the reproduced signals. These parameter modulations prevent feedback while preserving the natural characteristics of the room acoustics, as the underlying impulse responses remain authentic recordings of the actual space.

Inventive Principle:
Principle #35Parameter changes

3Object-generated harmful factors

If highly directional microphones are used to suppress feedback, then feedback is reduced, but homogeneous sound recording across the stage area becomes difficult

Engineering Contradiction:
ImprovefeedbackVSAvoidsound recording homogeneity
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The patent applies universality by using omnidirectional or less directional microphones that can uniformly capture sound from all directions across the stage area. These microphones serve multiple functions: recording sound sources evenly while also being compatible with the dynamic parameter variation technique that prevents feedback, thus achieving both homogeneous recording and feedback suppression.

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

4Adaptability or versatility

If variable absorber surfaces and adjustable reflectors are used to adjust acoustics, then acoustic adaptability is improved, but technical and financial effort increases

Engineering Contradiction:
Improveacoustic adaptabilityVSAvoidtechnical effort
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical systems with electronic signal processing. Instead of using physical variable absorber surfaces and adjustable reflectors to change room acoustics, the system uses electroacoustic signal processing with dynamically varying transfer functions and parameters. This substitution achieves acoustic adaptability for different event types without the complex mechanical infrastructure.

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

The system effectively improves room acoustics by creating a natural and lively sound image without feedback, allowing for flexible adjustment to different event types and spatial changes, while ensuring high feedback security and maintaining the natural characteristics of the room's acoustics.

Implementation Method 1

performing a respective convolution of the recorded sound signal with a respective impulse response function to generate different optimized sound signals

Methodology Applied
Scientific EffectConvolution:

Data Source

PatentEP1900250B1Electroacoustic method
Publication Date: 2010.05.19 MUELLER BBM GMBH
  • EP1900250B1 patent drawingFigure 1
  • EP1900250B1 patent drawingFigure 2
  • EP1900250B1 patent drawingFigure 3

AI summary

Disclosed is a method for improving the perceived acoustics of a room. Said method comprises the following steps: at least one sound signal is recorded in the vicinity of at least one sound source located in the room via a recording means; the recorded sound signal is replicated once with one respective pulse response function to generate different optimized sound signals, the respective pulse response function being chosen among a selection of predefined pulse response functions for the room; the optimized sound signals are reproduced via sound reproducing means located in the room. A different optimized sound signal is fed to each sound reproducing means while the optimized sound signals are fed to the reproducing means following one respective switching interval such that the same optimized sound signal is fed to no reproducing means in directly succeeding switching intervals.