Speech Enhancement Aggressiveness Control for Natural Denoising

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Solution Overview

Problem

Existing denoising techniques face a tradeoff between noise reduction and speech preservation, particularly when applied to diverse audio content such as dialog and music, leading to suboptimal results in either excessive noise or inadequate speech preservation.

Innovation Solution

Implementing an aggressiveness control parameter to manage the balance between speech preservation and noise reduction by adjusting the training and post-processing of machine learning models, including modifying training samples, target denoising masks, and model architecture, and using perceptual transformations based on human cochlear processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If aggressive speech enhancement processing is applied to improve speech intelligibility in noisy environments, then speech clarity is improved, but naturalness and quality of the speech deteriorate

Engineering Contradiction:
Improvespeech intelligibilityVSAvoidspeech naturalness
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts the degree of enhancement processing applied to different frequency components and time segments of speech based on noise conditions and speech characteristics. The enhancement amount is varied adaptively rather than applying uniform processing, allowing optimization of both intelligibility and naturalness in different contexts.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes multiple processing parameters including enhancement strength, spectral shaping, and temporal smoothing to balance intelligibility improvement with naturalness preservation. By adjusting these parameters based on speech quality metrics and noise levels, the system resolves the contradiction between aggressive enhancement and natural speech quality.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If speech enhancement processing is applied to improve speech quality, then speech clarity is improved, but musical sounds and background audio content are distorted or lost

Engineering Contradiction:
Improvespeech clarityVSAvoidbackground audio content
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The system applies enhancement processing selectively to speech frequency regions while preserving non-speech audio content in other frequency bands. By identifying speech segments and applying enhancement only where speech is present, the system improves speech clarity without distorting musical sounds or background audio that fall outside the speech spectrum.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system uses an audio content analysis intermediary that identifies and classifies different audio components (speech, music, background sounds). This intermediary guides the enhancement processing to target only speech portions, preventing distortion of other audio content while still achieving speech clarity improvement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If traditional speech enhancement methods are used to reduce noise, then noise suppression is achieved, but speech sounds unnatural and quality degrades

Engineering Contradiction:
Improvenoise suppressionVSAvoidspeech quality
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The system dynamically adapts the noise suppression strength based on the estimated noise level and speech characteristics. In high-noise conditions, stronger suppression is applied, while in lower-noise conditions, suppression is reduced to preserve naturalness. This dynamic adjustment resolves the contradiction between noise suppression effectiveness and speech quality preservation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from speech quality evaluation and naturalness metrics to adjust the enhancement and noise suppression parameters. When speech sounds unnatural, the system reduces processing intensity or adjusts spectral shaping to restore naturalness, thereby maintaining speech quality while still achieving noise suppression.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4430607B1Control of speech preservation in speech enhancement
Publication Date: 2026.04.29 DOLBY LABORATORIES LICENSING CORP
  • EP4430607B1 patent drawingFigure 1
  • EP4430607B1 patent drawingFigure 2
  • EP4430607B1 patent drawingFigure 3

AI summary

A method for performing denoising on audio signals is provided. In some implementations, the method involves determining an aggressiveness control parameter value that modulates a degree of speech preservation to be applied. In some implementations, the method involves obtaining a training set of training samples, a training sample having a noisy audio signal and a target denoising mask. In some implementations, the method involves training a machine learning model, wherein the trained machine learning model is usable to take, as an input, a noisy test audio signal and generate a corresponding denoised test audio signal, and wherein the aggressiveness control parameter value is used for: 1) generating a frequency domain representation of the noisy audio signals included in the training set; 2) modifying the target denoising masks; 3) determining an architecture of the machine learning model; or 4) determining a loss during training of the machine learning model.