Multi-Pass Speech Enhancement With DNN Feedback Noise Suppression

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Solution Overview

Problem

Existing neural network architectures for speech enhancement in single-channel audio signals require significant processing power and memory, making them unsuitable for low-power edge devices like battery-powered headsets or earbuds, and often result in speech distortion or noise leakage.

Innovation Solution

A multi-pass neural network system that combines a deep neural network (DNN) with a statistical signal processor (SSP) to iteratively refine speech signals, using a feedback loop to recursively filter residual noise, reducing the need for additional memory and computational resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If larger neural networks are used for speech enhancement, then speech enhancement accuracy is improved, but processing power and memory requirements increase

Engineering Contradiction:
Improvespeech enhancement accuracyVSAvoidprocessing power and memory requirements
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the speech enhancement task into multiple passes, where each pass processes the audio signal through the same neural network model. Instead of using one large neural network, the system applies a smaller network iteratively multiple times (e.g., 2-5 passes), achieving comparable accuracy to larger networks while reducing memory requirements and power consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements continuous refinement by feeding the output of each pass back as input to the next pass. This iterative process continuously improves speech enhancement quality without requiring additional model complexity, maintaining accuracy while optimizing resource usage through repeated application of the same computational structure.

Inventive Principle:
Principle #20Continuity of useful action

2Measurement precision

If larger neural networks are used for speech enhancement, then speech enhancement accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvespeech enhancement accuracyVSAvoidneural network architecture complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the enhancement task into temporal segments (multiple passes) rather than increasing spatial complexity (network size). Each pass uses the same relatively simple network structure, but the iterative temporal processing achieves cumulative improvement in accuracy, effectively trading temporal computation for spatial simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system applies periodic refinement through multiple discrete passes, where each pass periodically processes the signal to further reduce noise. This periodic application of the same transformation achieves progressive improvement without requiring increasingly complex network architectures.

Inventive Principle:
Principle #19Periodic action

3Use of energy by moving object

If smaller neural networks are used to reduce resource consumption, then processing power and memory requirements are reduced, but speech enhancement accuracy deteriorates

Engineering Contradiction:
Improveprocessing power and memory requirementsVSAvoidspeech enhancement accuracy
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent compensates for the limited capability of smaller networks by applying them continuously across multiple passes. Each pass provides incremental improvement, and the cumulative effect of repeated application achieves accuracy levels comparable to larger single-pass networks, effectively using temporal repetition to overcome spatial limitations.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system implements feedback by feeding the enhanced output from each pass back as input to the next pass. This feedback loop allows the smaller network to iteratively refine its output, progressively improving speech enhancement quality without requiring the network to be larger or more complex in a single transformation.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS12505849B2Multi-pass neural network for speech enhancement
Publication Date: 2025.12.23 SYNAPTICS INC
  • US12505849B2 patent drawing
  • US12505849B2 patent drawing
  • US12505849B2 patent drawing

AI summary

This disclosure provides methods, devices, and systems for audio signal processing. The present implementations more specifically relate to multi-pass neural networks configured for speech enhancement. In some aspects, a speech enhancement system may include a deep neural network (DNN) and a statistical signal processor (SSP). The DNN is configured to receive an input audio signal and infer a speech signal representing a speech component of the input audio signal based on a neural network model. The SSP is configured to further denoise the speech signal output by the DNN based on one or more statistical signal processing operations. In some implementations, the denoised speech signal may be fed back into the DNN (as an input audio signal) for further speech enhancement. As such, the speech enhancement system may recursively filter or suppress residual noise in the speech signal over a number of passes or iterations of a feedback loop.