Impulse Response Reverb Control for Adjustable Sound Density

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing reverberant sound adding techniques fail to effectively control sound density while simulating acoustic characteristics of a prescribed space, as they cannot reproduce the acoustic characteristics of a space using impulse responses.

Innovation Solution

A reverberant sound adding apparatus that generates a modified impulse response by adding noise to an impulse noise with random time intervals and convolves this response with an input audio signal, allowing for control over sound density through adjustment of noise proportions and time intervals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional reverberant sound adding techniques are used, then acoustic characteristics of a space can be simulated, but sound density cannot be controlled

Engineering Contradiction:

Improvesound density controlVSAvoidacoustic characteristics reproduction accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent segments the impulse response into multiple sections and applies different processing to each section. Specifically, it divides the impulse response into a first section (early reverberation) and a second section (late reverberation), allowing independent control of sound density for different temporal regions while maintaining accurate acoustic characteristics reproduction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes parameters of the impulse response by applying time-axis stretching to specific sections. It stretches the second section (late reverberation) more than the first section, thereby controlling sound density through parameter modification while preserving the overall acoustic characteristics of the space.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If sound density is increased using allpass filter techniques, then density sense is improved, but acoustic characteristics of the space cannot be reproduced

Engineering Contradiction:

Improvesound density controlVSAvoidacoustic characteristics simulation accuracy

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies dynamic processing by selectively stretching different sections of the impulse response based on their temporal characteristics. The degree of stretching varies dynamically across different sections, allowing sound density control in the late reverberation region while maintaining accurate acoustic characteristics reproduction in the early reverberation region.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies different processing qualities to different parts of the impulse response. The first section (early reverberation) maintains original timing characteristics for accurate acoustic reproduction, while the second section (late reverberation) receives time-axis stretching for sound density control, achieving local optimization of both qualities.

Inventive Principle:

Principle #3Local quality

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 the simulation of acoustic characteristics of a space while controlling sound density, resulting in reverberant sounds with a proper sense of expanse and direction, effectively reproducing the acoustic properties of the space.

Implementation Method 1

an impulse response convolver configured to convolve an input audio signal with the modified impulse response

Methodology Applied

Scientific EffectConvolution:

Implementation Method 2

a noise generator configured to generate a noise; an impulse noise generator configured to generate an impulse noise comprising an impulse sequence with random time intervals

Methodology Applied

Scientific EffectRandom noise generation:

Data Source

PatentUS9747889B2Reverberant sound adding apparatus, reverberant sound adding method, and reverberant sound adding program

Publication Date: 2017.08.29 YAMAHA CORP

AI summary

A reverberant sound adding apparatus includes a noise generator configured to generate a noise, an impulse noise generator configured to generate an impulse noise comprising an impulse sequence with random time intervals, an addition noise generator configured to generate an addition noise by adding the noise to the impulse noise, an impulse response generator configured to generate a modified impulse response by multiplying the addition noise by an amplitude characteristic of an impulse response that indicates acoustic characteristics of a space, and an impulse response convolver configured to convolve an input audio signal with the modified impulse response.